sample-practice-midterm

Part I (10 marks) - Multiple Choice (1 mark each) Place your answers in the boxes on the
answer sheet.

A. The structure of codeine, an alkaloid which is a derivative of opium and a drug which has
been used for centuries as a pain-killer and sedative, is shown below. Questions 1 to 2 pertain to
this structure.




↑


1. How many possible stereoisomers of codeine are there?
(a) 16 (b) 5 (c) 32 (d) 64 (e) 8

2. What is the configuration of the atom labeled “a” in the codeine structure?
(a) R (b) S (c) E (d) Z (e) not a stereocenter

3. Which is the best nucleophile in methanol?
(a) Br-
(b) NH3
(c) CH3S-
(d) CH3O-
(e) HO-

4. Rank the following in INCREASING acidity:




(a) A>B>C
(b) C>B>A
(c) B>A>C
(d) C>A>B
(e) A>C>B

5. Which of the following statements is TRUE regarding the reaction below?

, I- The mixture of products formed is optically active.
II-The stereoisomer shown is a meso compound.
III- The stereoisomer shown has a (1R, 2S) configuration.
IV-The stereoisomers formed are diastereomers relative to each other.
V-The stereoisomers are formed in a 50:50 ratio.

(a) I and IV only
(b) II, IV and V
(c) III, IV and V
(d) I, II, and IV
(e) I, III and IV



6. Which of the following mechanisms does NOT contain an error?




a)




b)




c)




d)