摘要：

The products of the solvolyses in glacial acetic acid of the p-toluenesulfonates of the stereoisomers of 3-phenyl-2-pentanol and 2-phenyl-3-pentanol have been analyzed. With regard to the acetate products of the reaction, the sulfonate ester of D-erythro-3-phenyl-2-pentanol and D-erythro-2-phenyl-3-pentanol give essentially the same mixture of 58% D-erythro-2-acetoxy-3-phenylpentane and 42% D-erythro-3-acetoxy-2-phenylpentane. Analogously, the sulfonate ester of D-threo-3-phenyl-2-pentanol gives about the same mixture of 58% D-threo-2-acetoxy-3-phenylpentane and 42% L-threo-3-acetoxy-2-phenylpentane as does the sulfonate ester of L-threo-2-phenyl-3-pentanol. Simple solvolysis reactions without involvement of the phenyl group account for only minor amounts of acetate product. These facts are interpreted in terms of phenonium sulfonate ion-pairs as intermediates in these reactions. The production of widely differing balances of olefinic products in the solvolyses of the four sulfonate esters provides evidence that the olefin and acetate products arise through at least two different primary processes. The presence of rearranged olefin (both conjugated and unconjugated) among the products in each experiment is interpreted as evidence for an isomerization reaction, the p-toluenesulfonate of D-erythro-3-phenyl-2-pentanol giving the p-toluenesulfonate of D-erythro-2-phenyl-3-pentanol and vice versa, and the p-toluenesulfonate of D-threo-3-phenyl-2-pentanol giving the p-toluenesulfonate of L-threo-2-phenyl-3-pentanol and vice versa. Different ratios of conjugated to unconjugated 2-phenylpentene were obtained from the p-toluenesulfonates of D-erythro-2-phenyl-3-pentanol and D-threo-2-phenyl-3-pentanol. These differences are interpreted in terms of the steric requirements for the formation of a phenyl vs. a hydrogen-bridge from materials of the erythro as compared to the threo configuration.

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