ortho-Directed metallation in the regiocontrolled synthesis of enantiopure 2- and/or 3-substituted (S)S (p-tolylsulfinyl)-1,4-benzoquinones

Article abstract of DOI:10.1016/S0957-4166(97)00062-1

Enantiomerically pure (S)S-(p-tolylsulfinyl)-1,4-benzoquinones with alkyl and methoxy substituents at C-2 and/or C-3 are synthesized by CAN oxidation of adequately substituted (S)S-(p-tolylsulfinyl)-1,4-dimethoxyaromatic precursors 2 or 3. These compounds were obtained by ortho-directed metallation or bromo-metal exchange from the corresponding p-methoxyanisoles in a highly regiocontrolled manner.