DIASTEREOSELECTIVE SYNTHESIS OF SPIRO-beta-LACTAMS VIA STAUDINGER REACTION

摘要

In this work,eleven new spiro-beta-lactams have been prepared using the Staudinger reaction of isomaleimides (1a-d) and carboxylic acids (chloroacetic acid,(-)-menthoxyacetic acid (7) and an oxazolidinone derived acid (10)) in the presence of triphosgene under mild condition.All reactions have been shown to be stereoselective.The new stereogenic centers were assigned by X-ray diffraction.