Vinylindenes and some heteroanalogues in the Diels-Alder reaction. III. Benzoquinone, 1,4-Naphthoquinone and Benzo[b]thiophen 1,1-Dioxide as dienophiles

Abstract

3-Vinylindene gives high yields of adducts with 1,4-benzoquinone, 1,4- naphthoquinone, and benzo[b]-thiophen 1,1-dioxide. The structures and stereochemistries of the adducts are confirmed by p.m.r. and mass spectrometry. The effects of various oxidation procedures on the 1,4- naphthoquinone adduct are described; no skeletal rearrangement accompanies oxidation with oxygen in base. Some adducts of 34sopropenylindene and 2-methyl-3-vinylindene are also described.