The first totalsynthesis of 3-aza-11-thia-1,3,5(10)-trieno steroids was achieved via an intramolecular Diels–Alder cycloaddition of o-quinodimethanes as the key step.
We set out to describe a new and versatile method for preparing 3-aza-11-oxa-1,3,5(10)-trieno steroids via an intramolecular Diels-Alder cycloaddition of o-quinodimethanes as the key step. The characteristic H-1 and C-13 NMR spectroscopic features of the synthesized compounds are reported. (c) 2006 Elsevier Inc. All rights reserved.