The generation of a number of 1,2-diarylcyclopropane-1,2-diols is reported.
Reaction of these in situ with acid gives, primarily, an
α,β-unsaturated ketone in which the aryl substituent attached to the
double bond is that which is best able to stabilize a benzylic cation. It is
proposed that the reaction proceeds by O-protonation of
the cyclopropane-1,2-diol, followed by loss of water and opening of the
resulting cyclopropyl cation and final deprotonation. Such initial
O-protonation contrasts with the
C-protonation normally observed in the acidolysis of
cyclopropanols and other dialkyl- and alkylaryl-cyclopropane-1,2-diols.
报道了一系列1,2-二芳基环丙烷-1,2-二醇的生成。这些物质与酸在原位反应主要生成一种α,β-不饱和酮,其中连接到双键的芳基取代基是最能稳定苄基阳离子的。据推测,该反应通过环丙烷-1,2-二醇的O-质子化开始,随后失去水分并打开所得环丙基阳离子,最终去质子化。这种初始的O-质子化与通常观察到的C-质子化形成鲜明对比,后者在环丙醇和其他二烷基和烷基芳基环丙烷-1,2-二醇的酸解中通常被观察到。