Unusual fused tricyclic 2-azetidinones: Stereocontrolled synthesis of rigid dipeptide surrogates from beta-lactam-tethered imines via sequential cycloaddition/ring-closing metathesis

摘要

The combination of [3+2] and [2+2] cycloaddition reactions of 2-azetidinone-tethered imines with ring-closing methatesis offers an asymmetric entry to a variety of unusual fused tricyclic 2-azetidinones bearing a bridgehead nitrogen atom, related to conformationally restricted peptidomimetics. [References: 24]