EXAM 3
Comprehensive Organic Chemistry
CHEMISTRY 225b
Friday, March 31, 2006
NAME (print): _______________________________________________________________
TA:_____________________ Section Day:_________________ Section Time:__________
No Calculators! Take a few moments to look over the exam. Answer each question on the exam paper.
Important clues and structures are in bold.
Do all preliminary drawing or computations on the work sheets at the end of the exam. The work sheets will not be graded.
The exam is 55 minutes.
STOP writing and hand in your exam when you are asked to do so.
Remember: Neatness is to your advantage.
1. (25 pts) Structure ______
2. (25 pts) Potpourri ______
3. (25 pts) Reactions ______
4. (25 pts) Synthesis ______
___________________________________________
Total (100 pts)
1. ( 25 pts.) Structure: Compound (S)-A (C7H15Br) reacts readily with water to give optically active B, C7H16O. Compound A reacts with aq. NaOH to give achiral C (major) and optically active D (minor). When compound A is exposed to tert-C4H9OK/tert-C4H9OH, the ratio C/D decreases relative to the same ratio in the reaction with NaOH. What are the structures A-D? Explain and illustrate.
2. (5 x 5 pts. = 25 pts.) Potpourri: Complete each of the following questions.
a) The compound C14H25BrClN3O has how many degrees of unsaturation? Show work.
b) Circle the compound expected to have the greatest rate of E2 elimination.
c) Circle the greatest number of compounds at the same oxidation level.
d) Circle the terms that may apply to E2 reactions.
0o dihedral angle concerted bond cleavage isotope effect
bimolecular kinetically controlled
e) As a rule, a convergent synthesis is preferred over a linear synthesis. Explain briefly.
3. Reactions:
Complete each of the following questions. Pay attention to
stereochemistry, etc.
4. Synthesis: Design a synthesis of 3-ethyl-3-hexanol using only C1 and C2 compounds as the source of carbon atoms. All other reagents are available to you.
Work Sheets
Work Sheets
Work Sheets