Third Midterm. Witig 2 /18... reactions 3 /32... retro 1 4 /40... mxn 1 6 /20... max 2 7 /15... Extra Credit /5. Infrared Correlation Chart C O

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1 EM 234, Spring 2009 Third Midterm Ian R. Gould PRITED FIRST AME ASWER PRITED LAST AME KEY ASU ID or Posting ID Person on your LEFT (or Aisle)!PRIT YUR AME EA PAGE! READ TE DIRETIS AREFULLY! USE BLAK PAGES AS SRAT PAPER work on blank pages will not be graded... WRITE LEARLY! MLEULAR MDELS ARE ALLWED D T USE RED IK Person on your RIGT (or Aisle) 1 /10 nomen... 2 /18... Witig 3 /32... reactions 4 /40... retro 1 5 /20 retro /20... mxn 1 7 /15... max 2 D'T EAT, USE MM SESE! Li Be B F e a Mg Extra redit /5 e Al Si P S l Ar K a Sc Ti V r Mn Fe o i u Zn Ga Ge As Se Kr Rb Sr Y Zr b Mo Tc Ru Rh Pd Ag d In Sn Sb Te I s Ba Lu f Ta W Re s Ir Pt Au g Tl Pb Bi Po At Rn (cm -1 ) amine alcohol (!, ppm) small range range of values broad peak R 2 R R R 3300 variable and condition dependent, ca. 2-6! peaks Aromatic Ar mainly usually strong R R 2 R Xe Infrared orrelation hart Total (incl Extra) / R Interaction Energies, kcal/mol Eclipsing / ~1.0 /Me ~1.4 Me/Me ~2.6 Me/Et ~ R broad with spikes ~ broad ~ R2 broad ~ MR orrelation harts X R 2 R X Gauche Me/Me ~0.9 Et/Me ~0.95 i-pr/me ~1.1 t-bu/me ~2.7 Approximate oupling onstants, J (z), for 1 MR Spectra Alkyl 3 Y > 2 Y > 1 Y Alkyl ~10 ~2 ~ ~8 ~2 ~7 3 Y > 2 Y > 1 Y 0 0 Aromatic R 2

2 M 234, Spring 2009, Midterm #3-2 - AME Question 1 (10 pts.) Give an unambiguous IUPA name for the following compound. Be sure to use cis/trans, E/Z or R/S where appropriate. 5-bromo-(3R)-hydroxypentanal Question 2 (18 pts) a) Give the structures of the best carbonyl compound and the best phosphonium ylide to prepare the provided alkene in a Wittig synthesis (do not give the mechanism). P 3 + b) Show how your phosphonium ylide would be synthesized from an alkyl bromide. Do not show mechanisms, but give the reagents and conditions for each step of the synthesis. P 3 P 3 BuLi P 3 Extra credit question (5 pts).!-carotene is synthesized using which reaction? lemmenson Grignard Wittig Aldol from weekly work #12

3 M 234, Spring 2009, Midterm #3-3 - AME Question 3 (32 pts.) Provide the mising reaction products or reagents/conditions as required Ts a) 2 4 K/heat b) 1. / + (cat.) 2. Et c) S 3 2 S 4 3 S d) Ts (cat.) heat R

4 M 234, Spring 2009, Midterm #3 Question 4 (40 pts.) In each case, synthesize the (target) molecules on the right from the starting molecules the left. this can not be done in one reaction. Give reagents and conditions and the intermediate molecules at each step. Do not show any mechanisms or transient intermediates AME a) 1. 3 Mg / + P b) l (cat.) ab 4 Et Mg.TF 3 + Mg Mg

5 M 234, Spring 2009, Midterm #3-5 - AME Question 5 (20 pts.) Synthesize the (target) molecule on the right from the starting molecule the left. this can not be done in one reaction. Give reagents and conditions and the intermediate molecules at each step. Do not show any mechanisms or transient intermediates. 2 l All KMn 4 / /boil /Fe 3 Zn(g) 3 l/ 2 2 S 4 2 separate isomers

6 M 234, Spring 2009, Midterm #3-6 - AME Question 6 (20 pts.) Give a complete arrow-pushing mechanisms for the following reactions Show exactly where each proton comes from and goes to (no + + or - + ). Indicate the lewis acid/base for each ITERmolecular step (LB or LA) and whether they are also ønsted bases/acids ( or ) D T ATTEMPT T DRAW ALL RESAE TRIBUTRS F TE ITERMEDIATES, DRAW LY TE RELEVAT ES l l l

7 - 7 - M 234, Spring 2009, Midterm #3 AME Question 7 (35 pts.) Give a complete arrow-pushing mechanisms for the following reactions Show exactly where each proton comes from and goes to (no + + or - + ). Indicate the lewis acid/base for each ITERmolecular step (LB or LA) and whether they are also ønsted bases/acids ( or ) DRAW ALL RESAE TRIBUTRS F TE ITERMEDIATES!! a) l b) Me l (cat.) Me Me Me Me LB LA l l 2