Synthesis of dl-.ALPHA.-tocopherol and dl-.ALPHA.-tocotrienol.

Abstract

α-Tocopherol (1) and α-tocotrienol (2) were synthesized in racemic form by a method in which their side chains were constructed by the coupling reaction of a key intermediate, 6-methoxymethoxy-2, 5, 7, 8-tetramethyl-2-(5-mercaptothiazolinyl-4-methyl-3-penten-1-yl) chroman (7), with geranyl bromide. Desulfurization of the reaction product and then hydrolysis afforded α-tocotrienol, which, upon reduction, gave the desired α-tocopherol in good yield. This method, using a mercaptothiazolinyl derivative, is more convenient than previous approaches which use the Wittig or Grignard reaction for the synthesis of the side chain.