Stereoselective synthesis of functionalised cycloalkene α-quaternary α-amino acid derivatives
作者:Mioara Andrei、Kjell Undheim
DOI:10.1016/j.tetasy.2003.10.013
日期:2004.1
A route for the preparation of unsaturated cyclic α-quaternary α-amino acid derivatives is described. Stepwise and stereocontrolled alkylations of the chiron (R)-2-isopropyl-3,6-dimethoxy-2,5-dihydropyrazine provided gem-disubstituted derivatives with an alkene and an alkoxo substituent. The Wacker oxidation was compatible for chemoselective oxidation of the alkene function. Formation of a methyl ketone
描述了制备不饱和环状α-季α-氨基酸衍生物的途径。Chiron(R)-2-异丙基-3,6-二甲氧基-2,5-二氢吡嗪的逐步和立体控制的烷基化提供了具有烯烃和烷氧基取代基的宝石-二取代的衍生物。Wacker氧化兼容于烯烃官能团的化学选择性氧化。甲基酮或醛的形成取决于底物。二氧羰基基质中的螺环化反应是通过碳酸铯在乙腈中的分子内羟醛缩合实现的。区域化学是底物依赖性的。在温和的酸性条件下裂解杂螺烷提供环状α-季α-氨基酸衍生物。