Polycavernoside A: The Prins Macrocyclization Approach
|
|
|
- Robyn Chambers
- 5 years ago
- Views:
Transcription
1 Polycavernoside A: The Prins Macrocyclization Approach Sang Kook Woo and Eun Lee Seoul National University, Seoul, Korea J. Am. Chem. Soc. 2010, 132, H Me H Me Me Me Marie-Céline Frantz Wipf Group - Current Literature April 24, 2010 Marie-Celine Wipf Group Page 1 of 11 4/26/2010
2 Polycavernoside A Isolated by Yasumoto from the edible red alga Polycavernosa tsudai in Guam in Responsible for sudden and fatal human intoxication in Guam in 1991 and in the Philippines in Symptoms: gastrointestinal (vomiting, diarrhea) and neurological (scratching, muscle spasms, paralysis) disorders. Cyanobacterial origin speculated. Group of macrolides with: structurally unique 13-membered central lactone ring disaccharide and trienyl side chains. Polycavernoside A analogs also isolated: Estimated LD 99 in mice (ip) of PA and PB: µg/kg. SAR: macrocyclic core and ipr-polyene side chain required for high toxicity. Hydrolysis of the disaccharide in the stomach would deliver the aglycone bioactive form. Postulated mechanism of action: triggers an initial extracellular calcium entry into the cytosol, resulting in membrane depolarization. R 2 R 3 Me Me Me H Me R 1 PC PC2 diene triene Polycavernosides C R 1 R 2 R 3 diene Ac Me triene Me Me Yotsu-Yamashita, M.; Haddock, R. L.; Yasumoto, T. J. Am. Chem. Soc. 1993, 115, Yotsu-Yamashita, M.; Yasumoto, T.; Yamada, S.; Bajarias, F. F. A.; Formeloza, M. A.; Romero, M. L.; Fukuyo, Y. Chem. Res. Toxicol. 2004, 17, Yotsu-Yamashita, M.; Seki, T.; Paul, V. J.; Naoki, H.; Yasumoto, T. Tetrahedron Lett. 1995, 36, Yotsu-Yamashita, M.; Abe, K.; Seki, T.; Fujiwara, K.; Yasumoto, T. Tetrahedron Lett. 2007, 48, Barriault, L.; Boulet, S. L.; Fujiwara, K.; Murai, A.; Paquette, L. A.; Yotsu-Yamashita, M. Bioorg. Med. Chem. Lett. 1999, 9, Cagide, E.; Louzao, M. C.; Ares, I. R.; Vieytes, M. R.; Yotsu-Yamashita, M.; Paquette, L. A.; Yasumoto, T. Cell. Phys. Biochem. 2007, 19, 185. Marie-Celine Wipf Group Page 2 of 11 4/26/2010
3 Polycavernoside A: Structure Determination & Synthesis Yasumoto (1993): determination (1D/2D NMR) of the partial relative structure of: each sugar component, bottom (C1-C8) and upper (C9-C15) halves of the macrolactone part. Murai (1995): determination (synthetically) of the relative configuration of the sequence of the fucose-xylose bottom half of the macrolactone. Murai (1998): 1st total synthesis & determination of the absolute configuration. Yotsu-Yamashita, M.; Haddock, R. L.; Yasumoto, T. J. Am. Chem. Soc. 1993, 115, Fujiwara, K.; Amano, S.; Murai, A. Chem. Lett. 1995, 855. Fujiwara, K.; Murai, A.; Yotsu-Yamashita, M.; Yasumoto, T. J. Am. Chem. Soc. 1998, 120, Paquette, L. A.; Barriault, L.; Pissarnitski, D. J. Am. Chem. Soc. 1999, 121, Paquette, L. A.; Barriault, L.; Pissarnitski, D.; Johnston, J. N. J. Am. Chem. Soc. 2000, 122, 619. White, J. D.; Blakemore, P. R.; Browder, C. C.; Hong, J.; Lincoln, C. M.; Nagornyy, P. A.; Robarge, L. A.; Wardrop, D. J. J. Am. Chem. Soc. 2001, 123, Blakemore, P. R.; Browder, C. C.; Hong, J.; Lincoln, C. M.; Nagornyy, P. A.; Robarge, L. A.; Wardrop, D. J.; White, J. D. J. rg. Chem. 2005, 70, Marie-Celine Wipf Group Page 3 of 11 4/26/2010
4 ( )-Polycavernoside A: Murai's synthesis (1998) H (R)-(+)-Glycidol Stereoselective intramol. H C 2 Me EtS 14 steps H Bn Michael cyclization 7 steps t-buk H C 2 Me H Bn 91% C 2 Me Bn SEt Sulfoxide anion addition Bn TBS LDA; then H PMB H 17 steps TBS PMB 1. Swern 2. PMB cleavage 3. Pinnick 4. Cl 3 PhCCl, Et 3 N; DMAP; >75% Me H H Bn Yamaguchi macrolactonization TsH, MeH/(Me) 3 CH 65-68% PMB - Thio/sulfinyl gps removal - TBS cleavage - Cyclic Me acetal formation H TBS SEt 33% TBS Bn + PMB H TBS EtS SEt 46% TBS Bn Me Bn MgBr + 1. Dihydroxylation 2. xidative cleavage 3. PG manipulation 4. Takai iodovinylation 5. TFA/H 2 /THF, >95% Acid-mediated acetal rearrangement H 1. TsCl 2. NaNH 2 Z/E sep. H H Hg Cp 2 ZrCl 2 LiEt 3 BH; I 2 I 1. Glycosidation 2. Bn cleavage 3. Cross-coupling I t-buli; HgCl steps (longest linear sequence) Me H Me Me Me ( )-Polycavernoside A Fujiwara, K.; Murai, A.; Yotsu-Yamashita, M.; Yasumoto, T. J. Am. Chem. Soc. 1998, 120, H Marie-Celine Wipf Group Page 4 of 11 4/26/2010
5 ( )-Polycavernoside A: Paquette's synthesis (1999) 32 steps (longest linear sequence) Paquette, L. A.; Barriault, L.; Pissarnitski, D. J. Am. Chem. Soc. 1999, 121, Paquette, L. A.; Barriault, L.; Pissarnitski, D.; Johnston, J. N. J. Am. Chem. Soc. 2000, 122, 619. Marie-Celine Wipf Group Page 5 of 11 4/26/2010
6 ( )-Polycavernoside A: White's synthesis (2001) 25 steps (longest linear sequence) White, J. D.; Blakemore, P. R.; Browder, C. C.; Hong, J.; Lincoln, C. M.; Nagornyy, P. A.; Robarge, L. A.; Wardrop, D. J. J. Am. Chem. Soc. 2001, 123, Blakemore, P. R.; Browder, C. C.; Hong, J.; Lincoln, C. M.; Nagornyy, P. A.; Robarge, L. A.; Wardrop, D. J.; White, J. D. J. rg. Chem. 2005, 70, Marie-Celine Wipf Group Page 6 of 11 4/26/2010
7 The Prins Reaction Prins cyclization vs competing oxonia-cope rearrangement Cyclization of (E)- and (Z)-Homoallylic Alcohols H EtCH, EtAlCl 2 TBS DCM Cl TBS 38% (40% r.s.m.) H TBS 9:1 Z/E EtCH, EtAlCl 2 DCM Cl + TBS Cl 1 : 3 (36%) TBS Stereochemical outcome for Prins cyclizations Excellent stereocontrol. All the substituents in the equatorial position. Selectivity of nucleophilic capture at C4 dependent on reactivity: - Highly reactive nucleophile (e.g.: Br - ) and electrophile: axial attack - Less reactive nucleophile (e.g.: Ac -, TFA - ) and electrophile: equatorial attack Crosby, S. R.; Harding, J. R.; King, C. D.; Parker, G. D.;Willis, C. L. rg. Lett. 2002, 4, 577. Barry, C. S. J.; Crosby, S. R.; Harding, J. R.; Hughes, R. A.; King, C. D.; Parker, G. D.; Willis, C. L. rg. Lett. 2003, 5, Jasti, R.; Anderson, C. D.; Rychnovsky, S. D. J. Am. Chem. Soc. 2005, 127, Jasti, R.; Rychnovsky, S. D. J. Am. Chem. Soc. 2006, 128, Marie-Celine Wipf Group Page 7 of 11 4/26/2010
8 The Prins Reaction: Application in Total Synthesis Application in the total synthesis of ( )-Blepharocalyxin D (Lee, 2007) ptimization of the conditions of Willis & coworkers Me (1.2 equiv.) H H H H Me H CH TESTf (4.0 equiv.) TMSAc (1.0 equiv.) Me Me H Ac Ac AcH (40 equiv.) rt, 1 h, 60% single diastereomer Ac Ac Ac ( )-Blepharocalyxin D H Application of the intramolecular Prins macrocyclization in the total synthesis of (+)-Neopeltolide (Lee, 2008) Ko, H. M.; Lee, D. G.; Kim, M. A.; Kim, H. J.; Park, J.; Lah, M. S.; Lee, E. rg. Lett. 2007, 9, 141. Ko, H. M.; Lee, D. G.; Kim, M. A.; Kim, H. J.; Park, J.; Lah, M. S.; Lee, E. Tetrahedron 2007, 63, Woo, S. K.; Kwon, M. S.; Lee, E. Angew. Chem., Int. Ed. 2008, 47, Marie-Celine Wipf Group Page 8 of 11 4/26/2010
9 ( )-Polycavernoside A Total Synthesis: Title Paper (enantiomer) Woo, S. K.; Lee, E. J. Am. Chem. Soc. 2010, 132, Marie-Celine Wipf Group Page 9 of 11 4/26/2010
10 ( )-Polycavernoside A Total Synthesis: Title Paper H TBS HF py 81% Et Et 1. Ac 2 DMAP 2. HF py 90% Ac H Et Et TESTf TMSAc AcH 85% Prins 6:1 d.r. Ac * Ac 3 ; PPh 3 79% Ac Ac CrCl 2 CHI 3 Complex product mixture H H Et Et Fortuitous rearrangement upon prolonged exposure to Takai conditions 1. 3 ; PPh 3 2. CrCl 2, CHI 3 3. K 2 C 3 54% H TESTf (10 equiv) TMSAc (15 equiv) AcH H 69% Prins I 5.5:1 d.r. H * Ac 1. NBS, 4 A MS Me SPh Me Me Bn Me 2. DDQ 3. PdCl 2 Bu 3 Sn 23% Pt 2, C K 2 C 3 ; 2. TPAP, NM 4 A MS 4 A MS Me 72% (3 steps) 6-endo intramol. alkyne hydration Ac H 1. DMD; PPTS, MeH Me H Me Me Me ( )-Polycavernoside A Ac Woo, S. K.; Lee, E. J. Am. Chem. Soc. 2010, 132, Marie-Celine Wipf Group Page 10 of 11 4/26/2010
11 Conclusion and Perspectives Novel approach for the total synthesis of ( )-Polycavernoside A. Use of a Prins macrocyclization strategy to build chemical complexity in a single step: 2 new rings 3 new stereocenters Comparison of synthetic routes to the macrocycle: Murai Paquette White Lee Longest linear sequence (steps) verall yield (%) Perspectives: further applications of the Prins macrocyclization strategy in the synthesis of complex natural products. Marie-Celine Wipf Group Page 11 of 11 4/26/2010
11-Step Enantioselective Synthesis of ( )-Lomaiviticin Aglycon
11-Step Enantioselective Synthesis of ( )-Lomaiviticin Aglycon Seth B. erzon, Liang Lu, Christina M. Woo, and Shivajirao L. Gholap J. Am. Chem. Soc. ASAP DI 10.1021/ja200034b Melissa Sprachman Current
Studies toward the Synthesis of Azadirachtin: Total Synthesis of a Fully Functionalized ABC Framework and Coupling with a Norbornene Domain
Studies toward the Synthesis of Azadirachtin: Total Synthesis of a Fully Functionalized ABC Framework and Coupling with a Norbornene Domain Nicolaou and Co-workers Angew. Chem. Int. Ed. 2005, 44, 3443
April 2002 CUME Organic Chemistry Department of Chemistry University of Missouri Columbia Saturday, April 6th, 2002 Dr.
April 2002 CUME Organic Chemistry Department of Chemistry University of Missouri Columbia Saturday, April 6th, 2002 Dr. Rainer Glaser Announced Reading: Prins Cyclization Reactions 1 Question 1. Aldol-Prins
A New Strategy for Efficient Synthesis of Medium and Large Ring Lactones without High Dilution or Slow Addition
A ew Strategy for Efficient Synthesis of Medium and Large ing Lactones without High Dilution or Slow Addition BF 3 Et 2 TIPS 2,4,6-collidine n + n+2 ' ' Zhao, W.; Li, Z; Sun, J. J. Am. Chem. Soc. 2013
Total Synthesis of the Proposed Structure of Briarellin J
Total Synthesis of the Proposed Structure of Briarellin J Michael T. Crimmins, Mark C. Mans, and Abimael D. Rodríguez. rg. Lett. 2010, ASAP Ac Ac originally proposed structure revised structure Eric E.
Synthesis of Abyssomicin C. Marie-Caroline Cordonnier Litterature Review 23/01/2009
Synthesis of Abyssomicin C Marie-Caroline Cordonnier Litterature Review 23/01/2009 Isolation Isolated in 2004 from the actinomycete Verrucosispora strain collected from a sediment at a depth of 289m in
Short Literature Presentation 10/4/2010 Erika A. Crane
Copper-Catalyzed Enantioselective Synthesis of trans-1- Alkyl-2-substituted Cyclopropanes via Tandem Conjugate Additions-Intramolecular Enolate Trapping artog, T. D.; Rudolph, A.; Macia B.; Minnaard, A.
CEM 852 Final Exam. May 5, 2011
CEM 852 Final Exam May 5, 2011 This exam consists of 8 pages. Please make certain that your exam has all of the necessary pages. Total points possible for this exam are 150. In answering your questions,
Synthesis of Azadirachtin: A Long but Successful Journey
ynthesis of Azadirachtin: A Long but uccessful Journey Gemma E. Veitch, Edith Beckmann, Brenda J. Burke, Alistair Boyer, arah L. Maslen, and teven V. Ley Angew. Chem. Int. Ed. 2007, Early View And Gemma
Approaches to the Synthesis. of Tetrahydropyrans. (and closely related heterocycles)
Approaches to the Synthesis of Tetrahydropyrans (and closely related heterocycles) William Morris Literature Presentation July 6, 2004 I. Intro A Nomenclature B Prevalence in Nature C Biosynthetic Considerations
Synthetic Developments Towards the Preparation of Erythromycin and Erythronolide Derivatives
ynthetic Developments Towards the Preparation of Erythromycin and Erythronolide Derivatives Russell C. mith Denmark Group Meeting 8-9-2005 most extensive project in organic synthesis this phenomenon is
Direct Oxidative Heck Cyclizations: Intramolecular Fujiwara-Moritani Arylations for the Synthesis of Functionalized Benzofurans and Dihydrobenzofurans
Direct xidative eck Cyclizations: Intramolecular Fujiwara-Moritani Arylations for the Synthesis of Functionalized Benzofurans and Dihydrobenzofurans by Zhang,.; Ferreira, E. M.; Stoltz, B. M. Angewandte
Total Synthesis and Absolute Stereochemical Assignment of ( )-Communesin F
Total Synthesis and Absolute Stereochemical Assignment of ( )-Communesin F Zhiwei Zuo, Weiqing Xie, Dawei Ma* Shanghai Institute of rganic Chemistry, Shanghai, China J. Am. Chem. Soc. 2010, 132, 13226-13228.
Transition Metal-Catalyzed 1,2-Diamination of Alkenes. Group Meeting Timothy Chang
Transition Metal-Catalyzed 1,2-Diamination of Alkenes Group Meeting Timothy Chang 04-27-10 Valuable 1,2-Diamine Motif H H S Biotin CH H H Pt Eloxatin (Anticaner) H 2 AcH CHEt 2 Tamiflu (Antiviral) Et Ph
II. Special Topics IIA. Enolate Chemistry & the Aldol Reaction
P. Wipf - Chem 2320 1 3/20/2006 II. Special Topics IIA. Enolate Chemistry & the Aldol Reaction Boger Notes: p. 147-206 (Chapter VIII) Carey/Sundberg: B p. 57-95 (Chapter B 2.1) Problem of the Day: Wang,
Electrophilic Carbenes
Electrophilic Carbenes The reaction of so-called stabilized diazo compounds with late transition metals produces a metal carbene intermediate that is electrophilic. The most common catalysts are Cu(I)
Domino Reactions in Total Synthesis! Reporter: Tianhe Yang! Supervisors: Prof. Yang! Prof. Chen! Prof. Tang!
1! Domino Reactions in Total Synthesis! Reporter: Tianhe Yang! Supervisors: Prof. Yang! Prof. Chen! Prof. Tang! 2! utline! 1. Brief Introduction! 2. ucleophilic Dominoes! 3. Electrophilc Dominoes! 4. Radical
Radical Reactions. Radical Stability!!! bond dissociation energies X Y X + Y. bond BDE (kcal/mol) bond BDE (kcal/mol) CH 3 CH 3 CH 2 95 O H R 2 C H
adical eactions adical Stability!!! bond dissociation energies X Y X Y bond BDE (kcal/mol) bond BDE (kcal/mol) C 3 104 108 C 3 C 2 98 110 95 2 C 102 (-) 93 (C-) 92 C 3 C 3 36 89 85 C 3 C 3 80 adical eactions
Silenes in organic synthesis: a concise synthesis of (±)-epi-picropodophyllin
lenes in organic synthesis: a concise synthesis of (±)-epi-picropodophyllin obert D. C. Pullin, Jonathan D. Sellars, and Patrick G. Steel* rg. Biomol. Chem., 2007, 5, 3201-3206 H H C Adam Hoye Current
Highlights of Schmidt Reaction in the Last Ten Years
ighlights of Schmidt eaction in the Last Ten Years Dendrobates histrionicus Jack Liu ov. 18, 2003 Introduction Classical Schmidt reaction of aldehydes and carboxylic acids Classical Schmidt reaction of
A Modular Approach to Polyketide Building Blocks: Cycloadditions of Nitrile Oxides and Homoallylic Alcohols
A Modular Approach to Polyketide Building Blocks: Cycloadditions of itrile xides and Homoallylic Alcohols rganic Letters, 2005, ASAP ina Lohse-Fraefel and Erick M. Carreira * H H H + ' 1. t-bucl, -78 C
Synthesis of Amphidinolide X and an Exploration of Key Reactions
PJM 1/12/05 Synthesis of Amphidinolide X and an Exploration of Key eactions Lepage,.; Kattnig, E.; Furstner, A. JACS, 2004, 126, 15970-15971. 7 13 1 6 19 - Produced by marine dinoflagellates, Amphidinium
Total Synthesis of Oxazolomycin A
Total Synthesis of xazolomycin A Me xazolomycin A Me Eto, K.; Yoshino, M.; Takahashi K.; Ishihara, J.; atakeyama S. rg. Lett. 2011, 13, 5398 Dimas Paz Wipf group- Current Literature ctober 8, 2011 Dimas
Suggested solutions for Chapter 32
s for Chapter 32 32 PBLEM 1 Explain how the stereo- and regio- chemistry of these reactions are controlled. Why is the epoxidation only moderately diastereoselective, and why does the amine attack where
Stereoselective Organic Synthesis
Stereoselective rganic Synthesis Prabhat Arya Professor and Leader, Chemical Biology Program Dean, Academic Affairs, Institute of Life Sciences (An Associate Institute of University of yderabad Supported
Problem session (3) Daiki Kuwana. Please fill in the blank and explain reaction mechanisms and stereoselectivities.
Problem session (3) Daiki Kuwana Please fill in the blank and explain reaction mechanisms and stereoselectivities. 1. 1-1 1. (Ac) 2 (10 mol%), DPEphos (20 mol%) Et 3, toluene, 90 C 2. s 4 (14 mol%), M;
Large-Scale Synthesis of the Anti-Cancer Marine Natural Product (+)-Discodermolide
61.7 g prepared in 39 steps 43 chemists worked on the project which lasted 20 months Chris Kendall @ Wipf Group 1 3/27/04 8 22 1 5 24 carbon linear polypropionate chain containing stereocenters (6 hydroxyl
Synthesis of Resorcinylic Macrolides
Synthesis of Resorcinylic Macrolides X H H H H Cl X= Radicicol (1) X= CH2 Cycloproparadicicol (2) Danishefsky, S. J. J. Am. Chem. Soc. 2004, 126, ASAP Danishefsky, S. J. rg. Lett. 2004, 6, 413-416 Danishefsky,
Zr-Catalyzed Carbometallation
-Catalyzed Carbometallation C C C C ML n C C ML n ML n C C C C ML n ML n C C ML n Wipf Group esearch Topic Seminar Juan Arredondo November 13, 2004 Juan Arredondo @ Wipf Group 1 11/14/2004 Carbometallation
CEM 852 Final Exam. May 6, 2010
CEM 852 Final Exam May 6, 2010 This exam consists of 7 pages. Please make certain that your exam has all of the necessary pages. Total points possible for this exam are 150. n answering your questions,
Hennoxazole A. Philip Williams Group Meeting December 12, OMe. OMe 1 6 O H
ennoxazole A 1 6 11 17 24 Philip Williams Group eting December 12, 2007 Discovered Discovered by Paul cheuer at the University of awaii in 1991. Isolated 480mg ennoxazole A from 4.5kg from the sponge Polyfibrospongia
Ladderanes: Uses and Synthesis. Nicholas Anderson Denmark Group Meeting October 28, 2008
Ladderanes: Uses and Synthesis icholas Anderson Denmark Group Meeting ctober 28, 2008 utline Ladderane types and classifications Potential applications of ladderanes Synthesis of ladderanes Ladderane natural
Comparative Synthesis of Ingenol. Tyler W. Wilson SED Group Meeting
Comparative Synthesis of Ingenol Tyler W. Wilson SED Group eting 2.27.07 Ingenol: Biology, Isolation, and istory During WWII a latex was manufactured by precipitating the milky juice of the Euphorbia Ingen
CEM 852 Exam-2 April 11, 2015
CEM 852 Exam-2 April 11, 2015 This exam consists of 6 pages. Please make certain that your exam has all of the necessary pages. Total points possible for this exam are 100. In answering your questions,
Syntheses of Leucascandrolide A. Supergroup Meeting August 4 th, 2004 Yu Yuan
Syntheses of Leucascandrolide A Supergroup Meeting August 4 th, 2004 Yu Yuan Leucascandrolide A Me Me Me Dambrosio, M.; Guerriero, A.; Debitus, C.; Pietra, F. elvetica Chimica Acta 1996, 79, 51-60 Me 1
Massachusetts Institute of Technology Organic Chemistry 5.512
Massachusetts Institute of Technology rganic Chemistry 5.512 Problem Set 6 Solutions Stereocontrolled Carbonyl Reduction and Aldol Reactions May 5, 2006 Lucy Kohnen ( The target compound was used as an
Ynolate Chemistry. Jeff Kallemeyn October 22, 2002
Ynolate Chemistry While enolates have numbered among the most important reagents of organic chemistry for more than a century, ynolates have hitherto remained unknown although their chemistry should be
Introduction to Synthesis: Design (CHE686) Spring 2015 Exam #1 3/6/15
Introduction to ynthesis: Design (CE686) pring 2015 Exam #1 3/6/15 AME: KEY ome Pointers: 1. ELAX!! 2. ead the instructions for each question carefully. Be sure you understand what is required. If you
Convergent Route to ent-kaurane Diterpenoids: Total Synthesis of Lungshengenin D and 1α6α- Diacetoxy-ent-kaura-9(11),16-dien- 12,15-dione
Convergent Route to ent-kaurane Diterpenoids: Total Synthesis of Lungshengenin D and 1α6α- Diacetoxy-ent-kaura-9(11),16-dien- 12,15-dione Xiangbo Zhao, Wu Li, Junjie Wang, and Dawei Ma* Shanghai Institute
Short Lit
Short Lit. - 7-12-2010 Jonathan A. Brekan a Department of Chemistry, orthwestern University, 2145 Sheridan Road, 60208, Evanston, Illinois, United States of America Citronellal Monoterpenoid distillate
A Tandem Semipinacol Rearrangement/Alkylation of a-epoxy Alcohols: An Efficient and Stereoselective Approach to Multifunctional 1,3-Diols
A Tandem Semipinacol Rearrangement/Alkylation of a-epoxy Alcohols: An Efficient and Stereoselective Approach to Multifunctional 1,3-Diols B() 2 H H B() 2 H H Hu, X.-D.; Fan, C.-A.; Zhang, F.-M.; Tu, Y.
Amphoteric Molecules < Chemistry of Andrei K. Yudin > Hyung Min Chi 17 JUNE 2014
Amphoteric Molecules < Chemistry of Andrei K. Yudin > Hyung Min Chi 17 JUNE 2014 1 Amphoteric molecules Amphoteric? Greek word amphoteros (both of two) Amphoterism in acid/base chemistry Amino acids (thermodynatic
I. Liu Lab. Ka<e Boknevitz 1
A ighly Convergent Total Synthesis of Leustroducsin B Barry M. Trost,* Berenger Biannic, Cheyenne S. Brindle, B. Michael Keefe, Thomas J. unger, and Ming-Yu gai Department of Chemistry, Stanford University,
James D. White. A very productive professor 64 students graduated from his lab 94 postdocs have worked in his lab. Education Experience
A very productive professor 64 students graduated from his lab 94 postdocs have worked in his lab Education Experience Fraser Fleming University of Drexel Pavel agory University of Michigan Cambridge University,
CEM 852 Exam LDA, THF, 0 C, 15 min; then
CEM 85 Exam- April, 005 This exam consists of 5 pages. Please write ALL your answers in the answer books. Please write legibly and draw all structures clearly. Good luck. 1. Provide examples of the following
Organic Cumulative Exam October 13, 2016
rganic Cumulative Exam ctober 3, 206 Answer only three of the five questions. o more than three question answers will be graded and any work not to be considered must be clearly marked as such. Clearly
A 1,3 Strain and the Anomeric Effect. Michael Shaghafi Chem. Topics Feb. 6, 2012
A 1,3 Strain and the Anomeric Effect Michael Shaghafi Chem. Topics Feb. 6, 2012 Introduction: Definition of A 1,3 Strain m L L m m 3 L 3 1 1 otation about σ-bond between α-stereocenter and olefin is associated
Memory of Chirality: A Strategy for Asymmetric Synthesis
Memory of Chirality: A trategy for Asymmetric ynthesis David J. Richard eptember 14, 2005 Two Forms of Chirality Absolute (tatic) Chirality 2 - Absolute chirality - orientation of functional groups at
Synthesis of Polyfluorinated and Polychlorinated Hydrocarbons
Synthesis of Polyfluorinated and Polychlorinated Hydrocarbons Yong Guan Feb. 13, 2009 Nicoletti, M.; O Hagan, D.; Slawin, A.M.Z. J. Am. Chem. Soc. 2005, 127, 482. Hunter, L.; O Hagan, D.; Slawin, A.M.Z.
Total Syntheses of Nominine
Total Syntheses of ominine i Literature t Group eting Lizzie Bryan ctober 17, 2007 Aconite Alkaloids Atidane V eatchane Cycloveatchane Aconitane etisan Muratake,. M.; atsume, M.; akai,. Tetrahedron, 2006,
Scope and Facial Selectivity of the Prins-Pinacol Synthesis of Attached Rings
Scope and Facial Selectivity of the Prins-Pinacol Synthesis of Attached Rings By Larry E. verman and Emile J. Velthuisen Leading Reference J. rg. Chem. 2006, 71, 1581-1587 Presented by Zhenyu Zhong Journal
Back to Sugars: Enzymatic Synthesis
Back to Sugars: Enzymatic Synthesis Zhensheng Ding ov. 04 orthrup, A. B.; M acm illan, D. W. C. Science 2004, 305, 1752 orthrup, A. B. and MacMillan, D. W. C. J. Am. Chem. Soc. 2002, 124, 6798-6799 orthrup,
Total Synthesis of ( )-Nakadomarin A
Total Synthesis of ( )-Nakadomarin A Pavol Jakubec, Dane M. Cockfield, and Darren J. Dixon University of Oxford and University of Manchester, UK J. Am. Chem. Soc. 2009, ASAP DOI: 10.1021/ja908399s Marie-Céline
Use of the non-aldol aldol process in the synthesis of the C1 C11 fragment of the tedanolides: use of lactol ethers in place of tetrahydrofurans
Pergamon Tetrahedron Letters 41 (2000) 9719 9723 TETRAHEDRON LETTERS Use of the non-aldol aldol process in the synthesis of the C1 C11 fragment of the tedanolides: use of lactol ethers in place of tetrahydrofurans
Highly Efficient, Convergent, and Enantioselective Synthesis of Phthioceranic Acid
Highly Efficient, Convergent, and Enantioselective Synthesis of Phthioceranic Acid Shiqing Xu, Akimichi Oda, Thomas Bobinski, Haijun Li, Yohei Matsueda, and Ei-ichi Negishi Angew. Chem. Int. Ed. 2015,
Literature Report IX. Cho, S. H. et al. Org. Lett. 2016, 18, Cho, S. H. et al. Angew. Chem. Int. Ed. 2017, 56,
Literature Report IX ynthesis of β-aminoboronates by Copper(I)- Catalyzed Addition of Diborylalkanes to Imines Reporter Checker Date : hubo Hu : Xiaoyong Zhai : 2017-9-1818 Cho,. H. et al. rg. Lett. 2016,
Suggested solutions for Chapter 27
uggested solutions for Chapter 27 27 PRBLEM 1 uggest a mechanism for this reaction, commenting on the selectivity and the stereochemistry. Me 2 1. t-buk 2. Raney Ni Et The opportunity to explore the consequences
MULTICOMPONENT REACTIONS AND ORGANOCATALYSIS: A SUITABLE COMBINATION FOR STEREOSELECTIVE SYNTHESIS OF HIGHLY SUBSTITUTED BENZAZEPINES
MULTICMPET REACTIS AD RGACATALYSIS: A SUITABLE CMBIATI FR STERESELECTIVE SYTHESIS F HIGHLY SUBSTITUTED BEZAZEPIES Martina Spallarossa Department of Chemistry and Industrial Chemistry, University of Genoa
Rhenium-Catalyzed Synthesis of Multisubstituted Aromatic Compounds via C-C Single-Bond Cleavage
henium-catalyzed Synthesis of Multisubstituted Aromatic Compounds via C-C Single-Bond Cleavage Kuninobu, Y.; Takata,.; Kawata, A.; Takai, K. rg. Lett. ASAP Et 5 6 cat. [ebr(c) 3 (thf)] 2 5 6 Current Literature
Regioselective Reductive Cross-Coupling Reaction
Lit. Seminar. 2010. 6.16 Shinsuke Mouri (D3) Regioselective Reductive Cross-Coupling Reaction Glenn C. Micalizio obtained a Ph.D. at the University of Michigan in 2001 under the supervision of Professor
Aziridine Carboxylates, Carboxamides and Lactones: New Methods for Their Preparation and Their Transformation into α- and β-amino Acid Derivatives
Molecules 2000, 5 293 Aziridine Carboxylates, Carboxamides and Lactones: ew Methods for Their Preparation and Their Transformation into α- and β-amino Acid Derivatives obert H. Dodd Institut de Chimie
diene. If stereoisomeric mixtures form, indicate by drawing one and writing "+ enantiomer" and/or "+ diastereomer" in the box.
I. (9 points) Page A. Consider how varying the conditions of a reaction can vastly influence the rate of a reaction as well as the product(s) formed. First draw the product(s) that form in the reference
Total synthesis of marine natural products without using protecting groups
Total synthesis of marine natural products without using protecting groups ature (London, United Kingdom), Vol 446, March 2007, p. 404-408 Phil S. Baran, Thomas J. Maimone & Jeremy M. Richter Presented
Development of Chiral Phosphine Olefin Ligands and Their Use in Asymmetric Catalysis
Development of Chiral osphine lefin Ligands and Their Use in Asymmetric Catalysis 2 Wei-Liang Duan July 31, 2007 Research Works in Hayashi Group, Kyoto University (ct, 2003 Mar, 2007) Conventional Chiral
Catalytic Asymmetric Acyl Halide-Aldehyde Cyclocondensation Reactions of Substituted Ketenes
Catalytic Asymmetric Acyl Halide-Aldehyde Cyclocondensation eactions of Substituted Ketenes Scott G. elson, Cheng Zhu, and Xiaoqiang Shen J. Am. Chem Soc. 2004, 126, 14-15. Michael C. Myers, Literature
A Stereoselective Synthesis of (+)-Gonyautoxin 3
A Stereoselective Synthesis of (+)-Gonyautoxin 3 Mulcahy, J. V.; Du Bois, J. J. Am. Chem. Soc. 2008, 130, 12630-12631 Total Synthesis of (+)-Lithospermic Acid by Asymmetric Intramolecular Alkylation via
Total Synthesis of ( )-Virginiamycin M2
Total Synthesis of ( )-Virginiamycin M2 Jie Wu and James S. Panek, Angewandte Chemie International Edition, 2010, 49, 6165-6168 btained from the CDC Public ealth Image Library. Image credit: CDC/Dr. David
Guideline 5: Tactical Bonds
Guideline 5: Tactical Bonds f the molecule contains more than one functional group and hence there is a choice of which bonds to disconnect, how do you decide? Practice, but here are a few rough guidelines
Literature Report. A 11-Steps Total Synthesis of Magellanine through a Gold(І)-Catalyzed Dehydro Diels-Alder Reaction
Literature Report 11-Steps Total Synthesis of Magellanine through a Gold(І)-Catalyzed ehydro iels-lder Reaction Reporter: ong-qiang Shen Checker: Cong Liu ate: 2017/06/19 McGee, P.; Bétournay, G.; Barabé,
H CH 2 -OH (4) H b. H H (5) (6) a. b.
ame 215 F010-Exam o. 2 Page 2 I. (15 points) For each of the following pairs of compounds, predict which compound is more acidic. Compare the two underlined s for each pair and circle the compound that
Towards a Total Synthesis of Anatoxin-a(s)
Towards a Total Synthesis of Anatoxin-a(s) 2 P Me Me 2 Eric E. Buck Research Topic Seminar September 19, 2009 Eric Buck @ Wipf Group Page 1 of 27 10/3/2009 Background Anatoxin-a(s) is a neurotoxin produced
Strategies for Stereocontrolled Synthesis
Chemistry. Synthetic rganic Chemistry II Lecture 3 March, 2007 Rick L. Danheiser Massachusetts Institute of Technology! Thermodynamic Control Strategies! Kinetic Control Strategies! Strategies for the
JOC: 1985 Year in Review
Baran Group eting JC: 1985 Year in eview Syntheses discussed: thodoligies discussed: Quadrone 2 C (+)-irsutic Acid C (±) Coriolin (!)-Longifolene (!)-astanecine Manganese (III)-mediated "-lactone annulation
2. Reactions at Non-Anomeric Hydroxyl Groups
2. Reactions at Non-Anomeric Hydroxyl Groups 2.1 Ether-Type Protecting Groups u Alkyl and aryl ethers are relatively stable to acids and bases due to the high C bond energy (358 KJ/mol) u most useful ether-type
[3,3]-Sigmatropic rearrangements
![[3,3]-Sigmatropic rearrangements](/thumbs/75/71504906.jpg "[3,3]-Sigmatropic rearrangements")
1 [3,3]-Sigmatropic rearrangements heat R 1 R 3 R 1 R 3 R 1 R 3 A class of pericyclic reactions whose stereochemical outcome is governed by the geometric requirements of the cyclic transition state Reactions
Initials: 1. Chem 633: Advanced Organic Chemistry 2011 Final Exam
Initials: 1 ame: Chem 633: Advanced rganic Chemistry 2011 Final Exam Please answer the following questions clearly and concisely. In general, use pictures and less than 10 words in your answers. Write
Total Syntheses of Minfiensine
Total Syntheses of Minfiensine Douany, A. B.; umphreys, P. G.; verman, L. E.*; Wrobelski, A. D., J. Am. Chem. Soc. 2008, ASAP. D: 10.1021/ja800163v Shen, L.; Zhang, M.; Wu, Y.; Qin, Y.*, Angew. Chem. nt.
Towards Maoecrystal V: A Comparison of Recent Strategies
Towards Maoecrystal V: A Comparison of Recent Strategies Reactant/Reagent Current Literature: November 14, 2009 lissa Sprachman lissa Sprachman @ Wipf Group Page 1 of 14 12/28/2009 Maoecrystal V: Structural
Renaud Group Exercise Set
Renaud Group Exercise Set Prepared by ick Tappin 08/07/16 Spectroscopy 1. Deduce the structures for compounds A, B, and C C 6 10 3 A IR: 1745 and 1720 cm -1 13 C-MR: δ 208, 172, 51, 37, 32, and 27 ab 4
STEREOELECTRONIC EFFECTS (S.E.) IN ORGANIC CHEMISTRY
STEREOELECTRONIC EFFECTS (S.E.) IN ORGANIC CHEMISTRY Pierre Deslongchamps (version du 16 février 2010) Cf. pour le livre: http://pages.usherbrooke.ca/pdeslongchamps/cv.htm 1 SECTION 8 Stereoelectronic
Dual enantioselective control by heterocycles of (S)-indoline derivatives*
Pure Appl. Chem., Vol. 77, No. 12, pp. 2053 2059, 2005. DOI: 10.1351/pac200577122053 2005 IUPAC Dual enantioselective control by heterocycles of (S)-indoline derivatives* Yong Hae Kim, Doo Young Jung,
Total Synthesis of (+)-Sieboldine A J. Am. Chem. Soc. 2010, 132,
Total Synthesis of (+)-Sieboldine A J. Am. Chem. Soc. 2010, 132, 7876 7877. Current Literature Presentation 10JUL2010 Michael Yang Mike Yang @ Wipf Group Page 1 of 15 7/10/2010 Sieboldine A Background
Chem ORGANIC CHEMISTRY I
ORGANIC CHEMISTRY I CHEM 221 /2 01 Final Examination December 20, 2005 1400-1700 Dr. Cerrie ROGERS x x molecular model kits (without instructions) programmable calculators must be reset Chem 221 --- ORGANIC
Total Synthesis of Peloruside A Through Kinetic Lactonization and Relay Ring-Closing Metathesis Cyclization Reactions
Total Synthesis of Peloruside A Through Kinetic Lactonization and Relay Ring-Closing Metathesis Cyclization Reactions Thomas R. oye, Junha Jeon, Lucas C. Kopel, Troy D. Ryba, Manomi A. Tennakoon, and Yini
Copper-Catalyzed Synthesis of Esters from Ketones. Alkyl Group as a Leaving Group.
Copper-Catalyzed Synthesis of Esters from Ketones. Alkyl Group as a Leaving Group. akatani, Y.; Koizumi, Y.; Yamasaki, R.; Saito, S. rg. Lett. 2008, 10, 2067-2070. An Annulation Reaction for the Synthesis
Short Access to (+)-Lupinine and (+)-Epiquinamide via Double Hydroformylation
Short Access to (+)-Lupinine and (+)-Epiquinamide via Double Hydroformylation Kai Gao Checker: Changbin Yu Mann, A.* et al rg. Lett. 2009, ASAP Strategy for the formation of quinolizidine alkaloids R H
Nuggets of Knowledge for Chapter 17 Dienes and Aromaticity Chem 2320
Nuggets of Knowledge for Chapter 17 Dienes and Aromaticity Chem 2320 I. Isolated, cumulated, and conjugated dienes A diene is any compound with two or C=C's is a diene. Compounds containing more than two
Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes
![Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes](/thumbs/77/74720708.jpg "Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes")
Nickel-Catalyzed Three-Component [3+2+2] Cocyclization of Ethyl Cyclopropylideneacetate and Alkynes Selective Synthesis of Multisubstituted Cycloheptadienes 1 2 Cat. Ni 0 1 2 Komagawa, S.; Saito, S. Angew.
I. Introduction. Peng Zhao. Liu lab
Asymmetric Total Synthesis of Mycoleptodiscin A Shupeng Zhou, Hao Chen, Yijie Luo, Wenhao Zhang and Ang Li Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Road, Shanghai
(4) (5) (6) a. b. H. explanation: explanation:
ame Key 15 W11-Exam o. Page I. (15 points) For each of the following pairs of compounds, predict which compound is more acidic. Compare the two underlined s for each pair and circle the compound that is
Rhodium Catalyzed Alkyl C-H Insertion Reactions
Rhodium Catalyzed Alkyl C-H Insertion Reactions Rh Rh Jeff Kallemeyn 5/17/05 1. Cyclopropanation The Versatile and Reactive Rhodium Carbene R + Et Rh 2 (Ac) 4 R C 2 Et N 2 2. [2,3] sigmatropic rearrangement
1. Radical Substitution on Alkanes. 2. Radical Substitution with Alkenes. 3. Electrophilic Addition
1. Radical Substitution on Alkanes Only Cl and Br are useful at the laboratory level. Alkane reactivity: tertiary > secondary > primary > methyl Numbers below products give their relative yield. Relative
Organic Cumulative Exam December 1, 2001
Organic Cumulative Exam December 1, 2001 The Chemistry of Professor Eric Sorenson (PLEASE WRITE ALL ANSWERS ON THE FRONT PAGE OF THE EXAM) Professor Sorenson often derives ideas for his synthetic approaches
2/26/18. Practice Questions. Practice Questions B F. How many steps are there in this reaction?
Practice Questions Practice Questions D B F C E A G How many steps are there in this reaction? 1 Practice Questions D B F C E A G What is the highest-energy transitions state? Practice Questions D B F
Titanacyclopropanes as versatile intermediates for carbon carbon bond formation in reactions with unsaturated compounds*
Pure Appl. Chem., Vol. 72, No. 9, pp. 1715 1719, 2000. 2000 IUPAC Titanacyclopropanes as versatile intermediates for carbon carbon bond formation in reactions with unsaturated compounds* O. G. Kulinkovich
Total Synthesis of (+/-)-Goniomitine via a Formal Nitrile/Donor-Acceptor Cyclopropane [3 + 2] Cyclization
![Total Synthesis of (+/-)-Goniomitine via a Formal Nitrile/Donor-Acceptor Cyclopropane [3 + 2] Cyclization](/thumbs/82/85235286.jpg "Total Synthesis of (+/-)-Goniomitine via a Formal Nitrile/Donor-Acceptor Cyclopropane [3 + 2] Cyclization")
Total Synthesis of (+/-)-Goniomitine via a Formal itrile/donor-acceptor Cyclopropane [3 + 2] Cyclization (-)-Goniomitine Christian L. Morales and Brian Pagenkopf* rganic Letters, ASAP Current Literature
Total synthesis of Spongistatin
Literature Semminar 1. Introduction: Total synthesis of Spongistatin Chen Zhihua (M2) Isolation: Pettit et al. J. rg. Chem. 1993, 58, 1302. Kitagawa et al. Tetrahedron Lett. 1993, 34, 1993. Fusetani et
CHEMISTRY 252 Exam pts. Section 703 Grand Rapids 27 July 2006
ame PID CMISTRY 252 xam 1 100 pts. Section 70 Grand Rapids 27 July 2006 Make sure you have all 12 exam pages You will have 90 minutes to complete the 5 questions Please sign your name at the bottom of
Answer 3 out of the following 6 questions.
Answer 3 out of the following 6 questions. . J. Chem. Theory Comput. 205,, 4054 4063. (DI: 0.02/acs.jctc.5b00359) A. What is DLP-CCSD(T)? What does DLP stand for? Why is DLP-CCSD(T) faster than CCSD(T)?
Chiral Brønsted Acid Catalysis
Chiral Brønsted Acid Catalysis Aryl Aryl Aryl Aryl S CF 3 2 P Fe CF 3 CF 3 2 Jack Liu ov. 16, 2004 CF 3 Introduction Chiral Brønsted acid catalysis in nature: enzymes and peptides Chiral Brønsted acid