Asymmetric Tandem Wittig Rearrangement/Mannich Reactions
作者:Natalie C. Giampietro、John P. Wolfe
DOI:10.1002/anie.201000609
日期:2010.4.6
choice is yours: A highly stereoselective synthesis of α‐alkyl‐α‐hydroxy‐β‐amino esters is accomplished through a tandem Wittig‐rearrangement/Mannich reaction sequence. Transformations of N‐benzyl or N‐Boc imines proceed with high selectivity for formation of syn‐amino alcohol derivatives, whereas N‐Boc‐2‐(phenylsulfonyl)amines generate anti‐amino alcohol products. Auxiliary cleavage (transesterification
Asymmetric Tandem Wittig Rearrangement/Aldol Reactions
作者:Natalie C. Giampietro、Jeff W. Kampf、John P. Wolfe
DOI:10.1021/ja905930s
日期:2009.9.9
the asymmetric synthesis of alpha-alkyl-alpha,beta-dihydroxy esters that involves tandem Wittig rearrangement/aldol reactions of O-benzyl- or O-allylglycolate esters derived from 2-phenylcyclohexanol is described. This sequence constructs two C-C bonds and two stereocenters, one of which is quaternary, to afford syn diol products with excellent stereocontrol. Cleavage of the chiral auxiliary affords
描述了一种不对称合成 α-烷基-α,β-二羟基酯的新方法,该方法涉及衍生自 2-苯基环己醇的 O-苄基-或 O-烯丙基乙醇酸酯的串联 Wittig 重排/羟醛反应。该序列构建了两个 CC 键和两个立体中心,其中一个是四元的,以提供具有出色立体控制的合成二醇产品。手性助剂的裂解提供了高达 95% ee 的对映异构体富集产品。还描述了该方法在制备抗真菌剂交链桂酸合成中的关键中间体中的应用。