Addition of kinetic boron enolates generated from β-alkoxy methyl ketones to aldehydes. Density functional theory calculations on the transition structures
作者:Luiz C. Dias、Sávio M. Pinheiro、Vanda M. de Oliveira、Marco A.B. Ferreira、Cláudio F. Tormena、Andrea M. Aguilar、Julio Zukerman-Schpector、Edward R.T. Tiekink
DOI:10.1016/j.tet.2009.08.042
日期:2009.10
of 1,5-anti stereoinduction are obtained in boron enolate aldol reactions of 1,2-syn β-alkoxy methyl ketones with achiral aldehydes, when the β-alkoxy protecting group is part of a benzylidene acetal. We have also investigated the effects of the ligands on boron, the α-, β-, and γ-substituents and the β-alkoxy protecting group on the boron enolates, using density functional theory (B3LYP) and Møller–Plesset
enantioselective synthesis of the polyhydroxylatedchaincommon to marine natural products oscillariolide and phormidolidesA–C is described herein. This chain represents a synthetic challenge that needs to be solved before the total synthesis of this family of natural products can be approached. It contains seven stereocenters, six of them having a syn-hydroxylated functionality, and a tricky terminal (E)-bromomethoxydiene