A practical route for enantioselective total synthesis of (+)-11-deoxy-19-norcorticosterone via intramolecular Diels–Alder addition to an ortho-quinodimethane

Abstract

A convenient and practical route for enantioselective synthesis of the A-nor-B-trienic steroid 2via an intramolecular [4 + 2] cycloaddition of the olefinic ortho-quinodimethane 3 generated in situ by thermolysis of the olefinic benzocyclobutene 4 is reported. This leads to the total synthesis of (+)-11-deoxy-19-norcorticosterone 1 by use of a usual chemical manipulation on intermediate 2.