Synthesis of a morphinan from a benzocyclobutene derivative. X-Ray structure of 3,3-ethylenedioxy-1,2,3,4,4a,10aα-hexahydro-6,7-dimethoxy-phenanthrene-4aβ-carbonitrile

Abstract

A stereoselective synthesis of a morphinan ring system has been achieved by employing an intramolecular Diels–Alder reaction of a benzocyclobutene derivative (3) to provide a tricyclic compound (4) having a B/Ccis ring junction. After manipulation of a cyano group, the resulting amine (13) was converted into a morphinan derivative (16) by cyclization of an aminylium ion.