Conjugate addition reactions of chiral (E)-crotylsilanes: application to an asymmetric [3 + 2] cyclopentane annulation
作者:James S. Panek、Nareshkumar F. Jain
DOI:10.1021/jo00061a001
日期:1993.4
Functionalized (E)-crotylsilanes 1 undergo Lewis acid promoted conjugate addition reactions with alpha-substituted enals and methyl vinyl ketone 2 to produce tetrasubstituted cyclopentanes 3 with high levels of diastereoselection. The reaction is believed to proceed by an initial 1,4-addition which is followed by a 1,2-silyl migration and a final cyclization step involving the derived boron enolate resulting in the construction of the cyclopentanoid product.