A new synthesis of(-)-rishitin (1) is reported, starting with chiral pool molecules. The crucial step is a stereoselective vinyl radical cyclization, which gives a 10:1 ratio of 21 to 22. (C) 1997 Elsevier Science Ltd.
The regio- and stereo-selective synthesis of rishitin (1) from (−)-α-santonin (2) is described. The transformation involves twelve steps including two known processes, the overall yield amounting to 2.9% from the santonin (2).
A new synthesis of(-)-rishitin (1) is reported, starting with chiral pool molecules. The crucial step is a stereoselective vinyl radical cyclization, which gives a 10:1 ratio of 21 to 22. (C) 1997 Elsevier Science Ltd.