Organic Chemistry 2. CHEM222 and CHEM234

Transcription

1 STUDET LAST AME: FIRST AME: STUDET UMBER: FACULTY F SCIECE FIAL EXAMIATI rganic Chemistry 2 CEM222 and CEM234 Examiners: Prof K. Auclair 9 am, 18 Dec 2007 Associate Examiner: Prof. M. Damha ISTRUCTIS: Please write your ame and ID number in the space provided above. This is a Closed Book Examination. Questions 1-29 are worth 3 points each. Question 30 is worth 6 points and question 31 is worth 7 points. This exam contains 23 pages. Answer questions 1-27 on the computer sheet using pencil only, and questions directly on the exam paper. Molecular models and pen/pencils are allowed. Calculators, dictionaries, cell phones, mp3 and others are T allowed. At the end you must hand in ALL pages of your exam. McGill University values academic integrity. Therefore all students must understand the meaning and consequences of cheating, plagiarism, and other academic offenses under the code of students conduct and disciplinary procedures. Good Luck! CEM222/234 Version 1 1

2 1- From the MS spectrum below, what can you conclude? a) the molecule contains one Br atom b) the molecule contains at least two atoms of Cl or Br c) the molecule is an alcohol d) the molecule contains an odd number of atoms 2- From the IR spectrum below, what can you conclude? a) presence of C= in the molecule b) presence of in the molecule c) presence of a triple bond in the molecule d) aromatic molecule CEM222/234 Version 1 2

3 3- Which molecule corresponds to the 1 MR below? a b c d CEM222/234 Version 1 3

4 4-Which of the protons of the molecule below is the most acidic? choose a letter from A-D) A B C D 5- Which of the atoms of the molecule below is the most basic? (choose a letter from A-D) C D A B CEM222/234 Version 1 4

5 6-Which molecule corresponds to the 13C MR below? C 3 C 3 C 3 C 3 C 3 C 3 a b c d CEM222/234 Version 1 5

6 7-What would be the major product of the reaction sequence below? 2 (B 3 ) a b c d 8-What would be the major product of the reaction sequence below? g(ac) 2 ab 4 a b c d CEM222/234 Version 1 6

7 9-Which of the reactions below would T be a good way to make? a) C 3 C + C 3 C 2 C 2 Cl + Mg b) C 3 C=CC 2 C 3 + B 3 followed by 2 2 c) C 3 CC 2 C 2 C 3 + LiAl 4 d) C 3 Cl + Mg + C 3 C 2 C 2 C 10-Which of the reaction sequences below would yield Br a) B 3 Br b) C 3 C 3 Br c) PBr 3 PDC d) C 3 C 3 abr CEM222/234 Version 1 7

8 11-What would be the major product of the reaction below? C 3 Li Et Et Et a b c d 12-What would be the best reagent to perform the transformation below?? 2 2 a) ab 4 b) DIBAL c) 2, Pt d) LiAl 4 CEM222/234 Version 1 8

9 13- Which of the reaction sequences below would T work as drawn? 3 C C 3 a) C 3 + b) S S S S + c) + d) C 3 C 3 C C What would be the major product of the reaction below? (C 3 ) 2 (C 3 ) 2 + (C 3 ) 2 (C 3 ) (C 3 ) 2 a b c d CEM222/234 Version 1 9

10 15-What reagent is the best to perform the reaction below? Ph 3 P + -C 2 -C 2 -C=C-C Ph 3 P=C-C 2 -C=C-C a) LiAl 4 b) a c) BuLi d) Et 2 16-What would be the major product of the reaction below? Cl- Ph 3 P + C a Ph 3 P C a b c d CEM222/234 Version 1 10

11 17-What would be the best way to make the molecule? a) + a heat b) + a heat c) a heat d) a heat CEM222/234 Version 1 11

12 18-Which of the reactions below is T likely to work as drawn? a) C 3 ac 3 C 3 b) 3 C 2 C 2 C C 2 C 2 C 3 ac 2 C 3 C 2 C 2 C 3 c) C 3 C 2 C 3 ac 3 PhC 2 C 3 Ph C3 d) C 3 ac 2 C 3 C 2 C 3 19-Which of the reaction sequences below is T likely to yield the molecule 2 C 2? a) 2 Mg Br C 2 b) 2 KMn 4 c) 2 Br ac + 2 d) CEM222/234 Version 1 12

13 20-Which of the reactions below is T likely to yield the molecule C 2 C 3? a) 2 C 2 C 3 + DCC DMAP 3 C 2 C 2 b) SCl 2 c) + a 2 C 2 C 3 3 C 2 C 2 d) + 21-What would be the major product of the reaction below? eat C 2 3 C a b c d CEM222/234 Version 1 13

14 22- Which of the reaction sequences below is T likely to yield the molecule 3 C 3 C 2? a) 3 C a 3 LiAl 4 3 C Br b) 3 C 2, Rai 3 C 2 c) 3 C C 2, Pd 3 C d) 3 C 3 acb 3 3 C CEM222/234 Version 1 14

15 23- Which of the reactions below is T likely to yield the product shown? a) 2 b) (C 3 ) 2 (C 3 ) 2 c) d) CEM222/234 Version 1 15

16 24- Which of the reactions below is T likely to yield the product shown? a) 3 C P 2 3 C b) 2 + BF 4 F c) ac 2 + C d) C 3 Cl 2 + C 3 25-The equilibrium below is important in the mechanism for acetal formation and cleavage. Which direction must be favored to FRM an acetal? C 3 + C 3 + a) forward b) reverse CEM222/234 Version 1 16

17 26- What is the first intermediate in the mechanism of the Michael addition shown below? C 3 + ac 3 - a + C 3 - a + C 3 - a + C 3 C 3 C 3 C 3 C 3 C 3 a b c d 27- During the Wittig reaction, what happens right after the attack of the ylide onto the carbonyl group? a) water is eliminated to give the double bond b) the phosphorous is eliminated c) the oxygen attacks the phosphorous to form a 4-membered ring d) the oxygen picks up a proton CEM222/234 Version 1 17

18 28- Draw the product for the reaction sequence below. LY the molecule in the box will be considered. partial points will be given. +, 2 +, 2 Ph 3 P=C-C 2 C 3 a 29- Draw the product for the reaction sequence below. LY the molecule in the box will be considered. partial points will be given. 2 1) C ) ab 3 C a (excess) C 2 C 3 CEM222/234 Version 1 18

19 30-Propose a multistep synthesis to carry out the transformation below (~6 steps): Ph Si Ph CC 3 Br CEM222/234 Version 1 19

20 30-Propose a multistep synthesis to carry out the transformation below (~8 steps): 2 Ph CEM222/234 Version 1 20

21 CEM222/234 Version 1 21

22 R: 1-5 RC: 5-8 C-: C-: C-: C- 2 : C-Cl: C-Br: C-F: TMS : 0 F > Cl > Br > I CEM222/234 Version 1 22

23 IR Absorption Ranges C - (br,s) - (m) C- stretch (s) C C (m) C (m) combination bands (w) C= (s) C=C (m) C- (s) C- bend arom (s) Wavenumber (cm -1 ) Characteristic Infrared Absorptions of Functional Groups CEM222/234 Version 1 23