The synthesis of Beta-Carbonhomologous Intermediate of Norcardicin A. A General Method for Selective Preparation of The Beta-Lactam Ring in the Presence of Free Phenolic Hydroxyl Groups

Abstract

<em>The synthesis of cis-N-[</em><em>a</em><em>-carbobenzyloxy-</em><em>b</em><em>-(p-hydroxyphenyl)ethyl]-3-phthalimido-4-styryl-2-azetidinone is described. We have found that the electron-rich Schiff bases can afford the cis-</em><em>b</em><em>-lactam ring even in the presence of the free hydroxyl functions. The mechanisms of cis and trans-</em><em>b</em><em>-lactam ring formation are discussed. The discussions are consistent with the recent publications.</em>