Olivanic acid analogues. Part 6. Biomimetic synthesis of (±)-PS-5, (±)-6-Epi-PS-5, and (±)-benzyl MM22381

Abstract

Michael addition of thiols to 6-substituted azabicyclo[3.2.0]hept-2-ene-2-carboxylates, followed by reintroduction of the double bond with iodobenzene dichloride–pyridine under anhydrous conditions, provides a biomimetic strategy for the synthesis of 3-alkylthio-substituted olivanic acids (carbapenems) and their derivatives. This is illustrated by syntheses of representatives of the PS-5 and MM22381 series of antibacterial natural products.