申请人:Harvard University
公开号:US04665171A1
公开(公告)日:1987-05-12
1-Benzyl (or substituted benzyl)-3.beta.-[4(S)-aryloxazolidin-2-one-3-yl]-4.beta.-(2-arylvinyl)azet idin-2-ones are provided via cycloaddition of a 4(S)-aryloxazolidin-2-one-3-ylacetyl halide and an imine formed with a benzylamine and a 3-arylacrolein, e.g. cinnamaldehyde. The azetidinones are useful chiral intermediates in an asymmetric synthesis of 1-carba(1-dethia)-3-hydroxy-3-cephem-4-carboxylic acids and esters and to monocyclic .beta.-lactam antibiotics.
通过将4(S)-芳基氧唑烷-2-酮-3-基乙酰卤与苄胺和3-芳基丙烯醛(如肉桂醛)生成的亚胺进行环加成反应,可以制备1-苄(或取代苄基)-3-β-[4(S)-芳基氧唑烷-2-酮-3-基]-4-β-(2-芳基乙烯基)氮杂环丙酮。这些氮杂环丙酮是1-羰基(1-硫代)-3-羟基-3-头孢-4-羧酸和酯的手性中间体,在β-内酰胺类抗生素的不对称合成中起到重要作用。