STEREODIVERGENT ALLYLINDATION OF CYCLOPROPENES - REMARKABLE STEREODIRECTION AND ACCELERATION BY NEIGHBORING CARBOXYL AND HYDROXYL-GROUPS

Stereodivergent allylindation of cyclopropene derivatives has been rea lised regio- and stereoselectively. The coupling occurs exclusively at the gamma-carbon of allylic indium reagents and the more substituted carbon of the cyclopropene double bond The carboxyl and hydroxymethyl groups on the cyclopropene C-3-carbon exert significant effects in cis -direction and acceleration of the allylindation based on the intramol ecular chelation, whereas the ester group directs a trans-addition owi ng to the steric interaction with incoming allylindium reagents. (C) 1 998 Elsevier Science Ltd. All rights reserved.