Acyliminium Cyclization of Several Chiral N-Alkenylsuccinimide Derivatives

The acyliminium intermediate derived from (3R,4R)-N-(3-butenyl)-3,4-bis(benzyloxy)succinimide cyclized to give (8aS)- and (8aR)-hexahydro-3(2H)-indolidinone derivatives. On the other hand, those derived from N-3-hexenyl derivatives afforded (8aS)-hexahydro-3(2H)-indolidinone(s) exclusively. The geometry of the double bond reflected the stereochemistry of the products.