A Stereospecific Synthesis of Ring A-aromatic Steroids

Abstract
A diene synthesis using 2,6-xyloquinone as dienophile and boron trifluoride as catalyst does not follow the normal orientation rules and leads to a facile synthesis of ring A-aromatic steroids. A tetracyclic adduct prepared by a similar reaction and containing the steroidal C19-methyl group is also reported.