16.11The cis epoxide is achiral. It is a meso form containing a plane of symmetry. The trans isomer ischiral; its two mirror-image representations are not superposable.Neither the cis nor the trans epoxide is optically active when formed from the alkene. The cis epox-ide is achiral; it cannot be optically active. The trans epoxide is capable of optical activity but isformed as a racemic mixture because achiral starting materials are used.16.12(b)Azide ion is a good nucleophile, reacting readily with ethylene oxide to yield2-azidoethanol.(c)Ethylene oxide is hydrolyzed to ethylene glycol in the presence of aqueous base.(d)Phenyllithium reacts with ethylene oxide in a manner similar to that of a Grignard reagent.(e)The nucleophilic species here is the acetylenic anion CH3CH2C>C:2, which attacks a carbonatom of ethylene oxide to give 3-hexyn-1-ol.16.13Nucleophilic attack at C-2 of the starting epoxide will be faster than attack at C-1, because C-1 ismore sterically hindered. Compound A, corresponding to attack at C-1, is not as likely as com-
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