β-Lactam Antifungals. II. Enantiocontrolled Synthesis of (2R, 5S)-2-Hydroxymethyl-1-carbapenam, the Carba-Analog of a Clavam Antifungal

Abstract

(2R, 5S)-2-Hydroxymethyl-1-carbapenam (3), the carba-analog of an antifungal β-lactam (2R, 5S)-2-(hydroxymethyl)clavam (1), was synthesized in an enantiocontrolled manner, starting from the coupling reaction of an optically active phthalimido-acetate (3S, 4S)-4 and an allylsilane 7, followed by removal of the phthalimido group that was crucial for asymmetric induction. Hydroboration, protecting-group interconversion, and cyclization gave 3 stereoselectively.