A combination of a stereoselective addition of benzenethiol to α,β-unsaturated carboxylic acid derivatives and a subsequent substitution reaction of the corresponding sulfonium group with O-alkylhydroxamate anion has provided a new practical and stereoselective method for the construction of 3,4-disubstituted cis- and trans-β-lactams. A successful application was demonstrated by the formal asymmetric
苯硫醇立体选择性加成到α,β-不饱和
羧酸衍
生物中以及相应的sulf基随后与O-烷基异羟
肟酸根阴离子的取代反应相结合,为3,4-二取代顺式的构建提供了一种新的实用的立体选择性方法。-和反式-β-内酰胺。(+)-PS-5的形式不对称合成证明了成功的应用。