Observations Regarding the Regiochemical and Stereochemical Course of the Cyclization of Complex 5-Hexenyl Radicals: An Approach to Perhydronaphthalenes

Article abstract of DOI:10.1021/jo00249a015

Iodo lactones 4 and 5 were prepared from m-anisic acid (10) and m-(isopropylthio)benzoic acid (15), respectively, by using a reductive alkylation-haloctonization-free radical cyclization sequence.Enones 6-9 were prepared from benzoic acid by way of acid chloride 30 by using a palladium-catalyzed coupling reaction.Tri n-butyltin hydride mediated cyclization of 4-7 and 9 afforded substituted perhydronaphthalenes with good stereoselectivity.The radical derived from enone 8 gave perhydroindan 40.A transition-state geometry for the cyclization of enones 6-9 is proposed.