The synthesis of indoles bearing alkenyl and alkynyl moieties in different positions of the nucleus is described. These compounds are used as substrates for the intermolecular Pauson-Khand reaction leading to tetracyclic cyclopentenones with formation of additional five- to seven-membered rings. Products are related to alkaloids such as mitosenes, clausines, ergotamines, or apogeissochizines.
Copyright 2004 American Chemical Society