Organic Chemistry 354 Quiz - October 19, 2000

Dr. Sundin

1. For each of the following, state if the operating mechanism is SN1 or SN2 or if the mechanism can’t be determined from the given data.

Reaction is: R-X + Nu-1 ---> R-Nu + X-1.

a. Rate = [Nu-1] [R-X]. Answer

b. Optically active R-X gives racemic R-Nu. Answer

c. (CH3)3C-X is faster than CH3CH2CH2CH2-X. Answer

d. Reaction is faster when X = iodine than when X = chlorine. Answer

e. Reaction is faster when Nu = iodine than when Nu = chlorine. Answer

f. (CH3)3CCHXCH3 ---> (CH3)2CHCNu(CH3)2 Answer

2. For each of the following, give the correct answer:

a. Better nucleophile, iodide ion or chloride ion. Answer

b. Better leaving group, iodide ion or chloride ion. Answer

c. Better nucleophile, hydroxide ion or water. Answer

d. Better leaving group, hydroxide ion or water. Answer

e. Mechanism with a symmetrical intermediate, SN1 or SN2. Answer

3. For each of the following, state if the operating mechanism is SN1, SN2, E1, or E2, or if the mechanism can’t be determined from the given data.

Reaction is: R-X + Y-1 ---> ? (There are no other functional groups in R.).

a. Rate = [Y-1] [R-X] and the product is an alkene. Answer

b. Optically active R-X gives racemic R-Y. Answer

c. CH3CH2CH2CH2C-X gives predominantly CH3CH=CHCH3. Answer

d. Reactant is CH3X. Answer

e. Isopropyl iodide and isopropyl chloride give propene at the same rate. Answer

4. The same substrate can react by either the SN1 or SN2 mechanism depending upon other reaction conditions. Show the mechanism and predict the structure (including stereochemistry!) of all organic products in the following reactions:

a. Answer

b. Answer

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