Sasaki Michiko, Kawanishi Eiji, Nakai Yoshio, Matsumoto Tatsuya, Yamaguchi Kentaro, Takeda Kei
Department of Synthetic Organic Chemistry, Graduate School of Medical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima 734-8551, Japan.
J Org Chem. 2003 Nov 28;68(24):9330-9. doi: 10.1021/jo0352934.
Metalated O-silyl cyanohydrins of beta-silyl-alpha,beta-epoxyaldehyde have been found to serve as functionalized homoenolate equivalents by a tandem sequence involving base-promoted ring opening of the epoxide, Brook rearrangement, and alkylation of the resulting allylic anion. On the basis of mechanistic studies involving competitive experiments using the diastereomeric cyanohydrins, we propose a reaction pathway involving a silicate intermediate 36 formed by a concerted process via an anti-opening of the epoxide followed by the formation of an O-Si bond.
已发现β-硅基-α,β-环氧醛的金属化O-硅基氰醇可作为官能化的同烯醇酸酯等价物，通过一个串联序列实现，该序列涉及碱促进的环氧化物开环、布鲁克重排以及所得烯丙基阴离子的烷基化。基于使用非对映体氰醇进行竞争实验的机理研究，我们提出了一条反应途径，该途径涉及通过环氧化物的反式开环然后形成O-Si键的协同过程形成的硅酸盐中间体36。
