Stereoselektive Totalsynthese von rac-Yohimb-15-enon

Stereoselective Synthesis of rac-Yohimb-15-enone The Robinson annulation of an octahydroindolo[2,3-α]quinolizin-2-one is a general concept for the synthesis of yohimbine alkaloids. Using the phenylsulfonyl group for activation, a diastereoselective synthesis of rac-yohimben-17-one 21 has been developed. A new synthesis of aromatic amines 23 and 24 has been discovered.