Synthesis and Reactivity of Some Thiochroman-3,4-diones.

Article abstract of DOI:10.1016/S0040-4020(01)85270-4

Thiochroman-3,4-diones, which result from the reaction of thiochroman-4-ones with isoamyl nitrite, form fused heterocycles on reaction with 1,2-diamines and with p-anisaldehyde and ammonium acetate.Cyclopenta<1>benzothiopyran-2-one, formed on reaction with dibenzyl ketone, yields a dibenzothiopyran after cycloaddition of DMAD.With methyl magnesium iodide, a mixture of thiochroman-3- and 4-ols is formed which was separated only after the selective dehydration of the 4-ol.The resulting 4-methylene derivative was isolated as the hetero Diels-Alder spiro-linked adduct.