PREPARATION OF ALKYL ESTERS OF N-PROTECTED OXO-AZACYCLOALKYLCARBOXYLIC ACIDS

摘要

A process for the preparation of alkyl esters of N-protected oxo-azacycloalkylcarboxylic acids of Formula III: comprises contacting a ketosulfoxonium ylide of Formula II: with an iridium catalyst to obtain Compound III, wherein PG1 is an amine protective group group; k is 0, 1, or 2; and RU, R1, R2, and R3 are defined herein. An embodiment of the process further com rises contacting a compound of Formula I: with a sulfoxonium halide of formula (RU)3S(O)Z, wherein Z is halide, in the presence of a strong base to obtain Compound II. Additional embodiments add a series of process steps leading to the synthesis of 7-oxo-1,6- diazabicyclo[3.2.1]octanes suitable for use as ß-lactamase inhibitors.