Stereoselective total synthesis of a novel D-homosteroid by a twofold Heck reaction

The D-homosteroid 1 was synthesized by two successive Heck reactions starting from enantiopure 3 and the bromoarene 2 containing a (Z)-bromovinyl group. The first intermolecular Pd-catalyzed reaction leads to 6 in a highly regio- and diastereoselective way which forms 1 with an unusual cis-junction of the rings B and C by a second intramolecular Heck reaction.