Asymmetric synthesis of cyclic β-hydroxyallylsilanes via sequential allyltitanation-ring closing metathesis
作者:Jean-Michel Adam、Laurence de Fays、Michel Laguerre、Léon Ghosez
DOI:10.1016/j.tet.2004.05.058
日期:2004.8
Highly enantioenriched cyclic β-hydroxyallylsilanes have been prepared via enantioselective allylation of unsaturated aldehydes using a chiralallyltitaniumreagent, followed by a ring-closing metathesis. Functionalized rings of various sizes have been synthesized and the electronic effect of the silicon group in the RCM reaction has been studied. The resulting cyclic β-hydroxyallylsilanes reacted
The Lewis acid promotedallylation of aldehydes has become an important carbon−carbon bond forming reaction in organic chemistry. In this context, we have developed an alternative over existing catalytic processes, wherein aldehydes are subject in acetonitrile to reaction of allylation with allyltributylstannane in the presence of 1.0 equiv of cerium(III) chloride heptahydrate (CeCl3·7H2O), an inexpensive