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