Influence of Geminal Disubstitution on Samarium Diiodide Induced Reductive Cyclizations of gamma-Aryl Ketones

摘要

Geminal disubstitution at the alkyl chain of gamma-aryl ketones significantly influences the efficacy of samarium diiodide induced cyclizations providing significantly higher yields. beta,beta-Disubstituted aryl ketones 11a-e and gamma,gamma-disubstituted aryl ketone 14 could be converted into the corresponding hexahydronaphthalene derivatives in good yields. On the other hand, alpha,alpha-disubstituted ketone 9 only gave the secondary alcohol 10 along with recovered starting material. Aryl ketones containing substituents with heteroatoms could also be cyclized in high yields and substrates such as 11d with sterically demanding cyclic substituents efficiently afforded spiro compounds.