CHEMISTRY 216 WINTER TERM 2007 END OF TERM EXAM. Time Allowed 2 hours

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1 EMISTRY 216 WITER TERM 2007 ED F TERM EXAM Time Allowed 2 hours ame KEY GSI ame ID umber Lab Section Write legibly. Illegible or messy answers will not be graded. Read these instructions carefully. In questions 5 10 you will be given the molecular formula, IR, 13 MR and 1 MR spectra of a compound. You are required to deduce its molecular structure and give your answer as part d of each question. If you answer part d completely correctly you will receive full credit for the question. The answers to parts a, b, and c will help you deduce the structure. You will receive partial credit by answering these questions if your answer in part d is not correct. Tables summarizing IR stretching frequencies and 1 and 13 chemical shifts are provided. ote: 13 data refer to whether the carbon signal is expected to be a singlet (s), doublet (d), triplet (t) or quartet (q). The spectra you are given were recorded in decoupled mode (all the carbon peaks appear as singlets). owever, the multiplicity (when recorded in coupled mode) is indicated above each peak by these letters. The numbers below each peak in the 1 MR spectrum correspond to the relative integration for the peak. Total Points Points Awarded Total Points Points Awarded Q1 10 Q6 10 Q2 10 Q7 10 Q3 6 Q8 10 Q4 14 Q9 10 Q5 10 Q10 10 TTAL 100 1

2 ame Q1. For the molecule shown below sketch the expected proton MR spectrum. For full credit the chemical shift of each peak should be within 1 ppm of the expected value and you must show the correct coupling pattern, including relative intensities of peaks (do not worry about the size of the coupling constants). You do not need to indicate peak assignments in the spectrum points for having peaks in approx correct place up to 4 points 0.5 points for correct coupling pattern up to 4 points up to 2 points for showing peaks in approximately correct relative intensities

3 ame Q2. For the molecule shown below sketch the expected proton MR spectrum. For full credit the chemical shift of each peak should be within 1 ppm of the expected value and you must show the correct coupling pattern, including relative intensities of peaks (do not worry about the size of the coupling constants). You do not need to indicate peak assignments in the spectrum. Up to 7 points for correct shifts (one for each peak). Up to 3 points for correct splitting patterns (1 for the singlets, 1 for Each of the sets of Br doublets). I 2 3

4 ame B Q 3 For each of the peaks A, B,, D, E, F indicated in the IR spectrum shown above, in the corresponding boxes circle the atoms and bond(s) involved in the vibration giving rise to that peak. (nly need to circle one example of each bond to get credit) 4 A D E F A 1 pt 1 pt B 1 pt D 1 pt E F 1 pt 1 pt

5 ame Q 4 Assign each of the protons and carbons in the following structure to the appropriate peaks in the 1 and 13 MR spectra. Use the structure on page 5 for the 1 spectral assignments, and the structure of page 6 for the 13 assignments. 3 d c c b b f 3 2 e a 1 Point for each correctly identified peak. 5

6 ame Q 5 ompound A has molecular formula:

7 ame Q 5 a The number of double bond equivalents for compound A is: Q 5 b The functional group or groups present in compound A is/are: (write one functional group in each box, you may not need both boxes) 1 alkyl Q 5 c The substructures or fragments (containing more than one carbon atom) that make up compound A are: (write one substructure in each box, you may not need all the boxes) 2 Q 5 d The structure of compound A is: (draw your answer in the box) 10 points for correct structure. If not, 2 points for each box that is filled in correctly (up to 6 points). 7

8 ame Q 6 ompound A has molecular formula: 5 8 8

9 ame Q 6 a The number of double bond equivalents for compound A is: Q 6 b The functional group or groups present in compound A is/are: (write one functional group in each box, you may not need both boxes) 2 alkyl - = Q 6 c The substructures or fragments (containing more than one carbon atom) that make up compound A are: (write one substructure in each box, you may not need all the boxes) = Q 6 d The structure of compound A is: (draw your answer in the box) 10 points for correct structure. If not, 2 points for each box that is filled in correctly (up to 6 points). 9

10 ame Q 7 ompound A has molecular formula: ote: At 120 ppm, there are 2 peaks, one would be a singlet, and one a doublet in a proton coupled spectrum. 10

11 ame Q 7 a The number of double bond equivalents for compound A is: Q 7 b The functional group or groups present in compound A is/are: (write one functional group in each box, you may not need both boxes) 6 Q 7 c The substructures or fragments (containing more than one carbon atom) that make up compound A are: (write one substructure in each box, you may not need all the boxes) R Q 7 d The structure of compound A is: (draw your answer in the box) 10 points for correct structure. If not, 1 point for each box that is filled in correctly (up to 6 points). 11

12 ame Q 8 ompound A has molecular formula: o u.v. spectrum above 200 nm 12

13 ame 13

14 ame Q 8 a The number of double bond equivalents for compound A is: 2 Q 8 b The functional group or groups present in compound A is/are: (write one functional group in each box, you may not need both boxes) or Q 8 c The substructures or fragments (containing more than one carbon atom) that make up compound A are: (write one substructure in each box, you may not need all the boxes) Q 8 d The structure of compound A is: (draw your answer in the box) 10 points for correct structure. If not, 2 point for each box that is filled in correctly (up to 6 points). 14

15 ame Q 9 ompound B has molecular formula: 6 11 o peaks in u.v. spectrum above 200 nm 15

16 ame Q 9 a The number of double bond equivalents for compound B is: 2 Q 9 b The functional group or groups present in compound B is/are: (write one functional group in each box, you may not need both boxes) - Q 9 c The substructures or fragments (containing more than one carbon atom) that make up compound B are (write one substructure in each box, you may not need all the boxes) 3 3 Q 9 d The structure of compound B is (draw your answer in the box) 10 points for correct structure. If not, 2 point for each box that is filled in correctly (up to 6 points). 16

17 ame Q 10 ompound has molecular formula: U.V. spectrum peaks at 254 nm (int for interpreting proton MR: this is a chiral molecule) 17

18 ame Q 10 a The number of double bond equivalents for compound is: 5 Q 10 b The functional group or groups present in compound is/are: (write one functional group in each box, you may not need both boxes) - 2 Also K Q 10 c The substructures or fragments (containing more than one carbon atom) that make up compound are (write one substructure in each box, you may not need all the boxes) X Q 10 d The structure of compound is (draw your answer in the box) 10 points for correct structure. If not, 1 point for each box that is filled in correctly (up to 6 points). Y 2 18