Thermal and Catalyzed Intramolecular Diels-Alder Cyclizations of 2,8,10-Undecatrienals

Article abstract of DOI:10.1021/jo00383a012

A comparative study of thermal and Lewis acid catalyzed intramolecular Diels-Alder cyclizations of substituted 2,8,10-undecatrienals was undertaken to determine the effect of substituents on the stereochemistry of the reaction.Substituents examined included 11-methyl, 4-methyl, 9-Me₃Si, 7-OMOM, 7-OTBS, and anti-4,6-dimethyl in various combinations.In all cases, the catalyzed reactions were highly endo selective (90:10 or greater).In thermal cyclizations the 9-Me₃Si, the 4-methyl, and the anti-4,6-dimethyl derivatives showed complete endo selectivity and the 11-methyl derivative was moderately endo selective.