The syntheses of 5, 7, 8-trimethyl-, 2, 5, 7, 8-tetramethyl-, and 2, 2, 5, 7, 8-pentamethyl-6- hydroxythiochromans have been achieved by a Michael-type condensation of methyl acrylate and related methyl esters with 2, 3, 5-trimethyl-4-hydroxythiochromans followed by cyclization of the free acid and reduction. These three previously unknown compounds can serve as simple models for the still unknown 1-thia-a-tocopherol (l), which could not be ...
