Optically pure (S)-p-tolylsulfinyl substituted quinones were synthesized by deketalization of the corresponding quinone bisketals obtained by Andersen's type synthesis starting from 2- bromo-1, 4-dimethoxy aromatic derivatives, followed by anodic oxidation of the resulting sulfoxide.
[Gupta, Dharmendra N.; Hodge, Philip; Davies, J. Eric Journal of the Chemical Society, Perkin Transactions 1: Organic and Bio-Organic Chemistry (1972-1999), 1981 , p. 2970 - 2973]