Diastereoselective synthesis of α-bromo amides leading to diastereomerically enriched α-amino-, α-hydroxy- and α-thiocarboxylic acid derivatives
作者:By Robert S Ward、Andrew Pelter、Dominique Goubet、Martyn C Pritchard
DOI:10.1016/0957-4166(95)00032-k
日期:1995.2
prepared diastereoselectively starting from racemic α-bromo acids, and undergo epimerisation under appropriate conditions leading to an enhanced d.e.. By reacting the individual isomers or the mixture of diastereoisomers with a suitable nucleophile it is possible to obtain α-substituted carboxylic acids, including α-amino- α-hydroxy- and α-thiocarboxylic acid derivatives, in diastereomerically enriched
可以从外消旋α-溴酸开始非对映选择性地制备来源于Oppolzer樟脑的α-溴酰胺,并在适当条件下进行差向异构化,从而提高de值。通过使单个异构体或非对映异构体的混合物与合适的亲核试剂反应,可以获得非对映体富集形式的α-取代的羧酸,包括α-氨基-α-羟基和α-硫代羧酸衍生物。