text] Treatment of formyl alpha,beta-enones with a TiCl(4)-R(4)NX combination induces an intramolecular aldol cyclization to furnish 2-acyl-3-halocyclohexanol with three controlled consecutive stereogenic centers. The reaction of bis-alpha,beta-enones with the combination provides cyclic diketones with high stereoselectivity via an intramolecular Michael addition reaction.
[反应:见正文]用TiCl(4)-R(4)NX组合处理甲酰基α,β-烯酮可诱导分子内羟醛环化,以提供具有三个可控连续立体中心的2-酰基-3-卤代
环己醇。双-α,β-烯酮与该组合的反应通过分子内迈克尔加成反应提供具有高立体选择性的环状二酮。