A general synthesis of chiral C-4-alkylated azetidin-2-ones which are of potential use as intermediates for 1β-heteroatom-substituted carbapenems
Abstract
A highly diastereocontrolled alkylation at the C-4 position of 4-acetoxyazetidin-2-one (5) employing chiral tin(II) enolates of heteroatom-substituted acetyl derivatives (3a–e) furnishes new synthetic intermediates (6a–e) for 1β-heteroatom-substituted carbapenems (2).