SYNTHESIS AND ASYMMETRIC DIELS-ALDER REACTIONS OF (S)-2-p-TOLYLSULFINYL-1,4-BENZOQUINONE

Article abstract of DOI:10.1016/S0040-4039(00)99307-9

Optically pure (S)-2-p-tolylsulfinyl-1,4-benzoquinone (5) is readily obtained by deketalization of the corresponding quinone bisketal 4, synthesized by Andersen's type synthesis on 2-bromo-1,4-dimethoxybenzene (1) followed by anodic oxidation of the resulting sulfoxide.The Diels-Alder reaction of cyclopentadiene with 5 took place on C₅-C₆ dienophilic double bond showing high facial selectivity, which can be inverted by using different Lewis acids, and total endo selectivity.