A concise enantioselective synthesis of a fully oxygen substituted ring A taxol precursor

A concise synthesis of the oxygen substituted ring A compound found in Taxol® and Taxotere® starting from 2,2-dimethylcyclohexane-1,3-dione and proceeding via the key intermediates and , is described. The absolute configuration of was established from an X-ray crystal structure determination of a 4-bromophenylbenzoate derivative, viz. .