【摘要】 由（Ｒ）－丙叉甘油醛得到的手性亚胺１能与烯酮２ 在温和条件下迅速反应。而由混合酸酐或双烯酮代替酰氯，中间体也可能是烯酮或烯醇５。［２＋ ２］环加成在手性亚胺和烯酮２或烯醇５之间进行，前者主要生成顺式结构的β－内酰胺，后者为３－乙酰基反式异构体，且均有较高的立体选择性和较高的化学收率。更多还原

【Abstract】 Chiral imine 1 derived from (R) glyceraldehyde acetonide could rapidly react with ketenes 2 which was converted from mixed anhydride or acid chloride under mild conditions. Similarly, using diketene to replace mixed anhydride or acid chloride, intermediate enol 5 may be obtained. The main procedure, a classical [2+2] cycloaddition took place between the chiral imine 1 and ketenes 2 or enol 5, with the former to produce cis β Lactams 3 and with the latter to trans , but both were with high stereoselection and in chemical yield.更多还原