Forskolin has been synthesized in 11 steps with a 17% overall yield from ptychantins A and B, which have been isolated from the liverwort Ptychanthus striatus in good yield. The I a-hydroxy group was furnished by stereoselective reduction of the corresponding carbonyl group by sodium cyanoborohydride. The 9 alpha-hydroxy group was introduced stereoselectively by epoxidation of Delta(9,11)-enol ether.