Application of diethyl ethynylphosphonate to the synthesis of 3-phosphonylated β-lactams via the Kinugasa reaction

Abstract

The easily available diethyl ethynylphosphonate reacts with diverse aldonitrones under Kinugasa reaction conditions at room temperature, providing 3-phosphonylated β-lactams in good yields. In all cases, the reaction led to the trans-isomer exclusively. The trans-configuration was assigned based on 1H-NMR spectroscopic analysis. (Chemical Equation Presented).