480 CHAPTER 12 Reactions of Alcohols, Ethers, Epoxides, and Sulfur-Containing Compounds- One method used to synthesize an epoxide is to treat an alkene with an aqueous solution of followed by an aqueous solution
of sodium hydroxide.
a. Propose a mechanism for the conversion of cyclohexene into cyclohexene oxide by this method.
b. How many products are formed when cyclohexene oxide reacts with methoxide ion in methanol? Draw their structures. - Which of the following reactions occurs most rapidly? Why?
a. b. c.- When bromobenzene reacts with propene in a Heck reaction, two constitutional isomers are obtained as products. Give the
structures of the products and explain why two products are obtained. - A vicinal diol has OH groups on adjacent carbons. The dehydration of a vicinal diol is accompanied by a rearrangement called the
pinacol rearrangement. Propose a mechanism for this reaction. - Although 2-methyl-1,2-propanediol is an asymmetrical vicinal diol, only one product is obtained when it is dehydrated in the
presence of acid.
a. What is this product? b. Why is only one product formed? - What product is obtained when the following vicinal diol is heated in an acidic solution?
- Two stereoisomers are obtained from the reaction of cyclopentene oxide and dimethylamine. The R,R-isomer is used in the
manufacture of eclanamine, an antidepressant. What other isomer is obtained? - Propose a mechanism for each of the following reactions:
H 2 SO 4
∆H 3 C COCH 3CH 3+CH 3HOOH
H 3 C CH 3a.b.OH 2 SO 4
∆CH (^2) CH
3
O
CH
OH
OH
HO
CH 3 C
OH
CH 3
C
OH
CH 3
CH 3 CH 3 C
CH 3 O
CH 3
CCH 3 H 2 O
H 2 SO 4
∆ +
O
OH
Br
HO−
H 2 O
C(CH 3 ) 3 C(CH 3 ) 3
O
OH
C(CH 3 ) 3
Br
HO−
H 2 O
C(CH 3 ) 3
O
C(CH 3 ) 3
OH
Br
HO−
H 2 O
C(CH 3 ) 3
Br 2 ,
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