Oxidation process for preparing 4-acyloxy azetidinones in a two-phase system

摘要

Process for preparing compounds according to formula (I) <IMAGE> (I) wherein R1 and R2 represent a hydrogen atom or a protective group and R3 represents a C1-C10 alkyl or an aryl group, by oxidation of compounds according to formula (II) <IMAGE> (II) wherein R1, R2 and R3 have the above-mentioned meanings, in a two-phase system comprising: a) an organic phase including a 4-acylazetidinone compound (II) and an "onium" salt dissolved in a medium immiscible with water, b) an aqueous solution including an alkali or alkaline-earth metal salt of an organic or inorganic peracid. 4-Acyloxyazetidinones (I) are useful intermediates in the synthesis of anti-bacterial compounds.