A Temporary Stereocentre Approach for the Stereodivergent Synthesis of Either Enantiomer of α-Methyloctanal
作者:D. Gangani Niyadurupola、Iwan R. Davies、Richard Wisedale、Steven D. Bull
DOI:10.1002/ejoc.200700782
日期:2007.11
The aldol reaction of a chiral N-(acyl)oxazolidin-2-one with 2-methyleneoctanal or (E)-2-methyloct-2-enal affords chiral aldol products whose alkene functionalities were hydrogenated using Brown's or Wilkinson's catalyst to afford syn- or anti-selective products with excellent levels of diastereocontrol. Subsequent retro-aldol cleavage of these syn- or anti-adducts resulted in the formation of either
手性 N-(酰基) 恶唑烷-2-one 与 2-亚甲基辛醛或 (E)-2-methyloct-2-enal 的羟醛反应提供手性羟醛产物,其烯烃官能团使用布朗或威尔金森催化剂氢化以提供合成-或具有出色非对映控制水平的抗选择性产品。随后这些顺式或反加合物的逆羟醛裂解导致形成 α-甲基辛醛的 (R)-或 (S)-对映异构体,没有发生外消旋化,可以原位衍生化以提供手性对映体纯形式的二噻烷、醇或 α,β-不饱和酯产品。