2-Aryl-2-[1-(2-hydroxypropyl)]-1,3-dithianes as versatile building blocks for the preparation of enantiomerically pure drugs

Article abstract of DOI:10.1002/ardp.19953280306

An efficient access to chiral, non racemic arylbutanols 1a-c (ee > 98%) as drug intermediates is described. Thioacetalization of substituted benzaldehydes 3a-c with 1,3-propanedithiol gave 2-aryl-1,3-dithianes 4a-c. Lithiation of 4a-c followed by reaction with racemic, (R)- or (S)-propylene oxide, respectively, gave racemic, (R)- or (S)-hydroxyalkyldithianes 5a-c in high yields. Subsequent desulfurization with tributyltin hydride (TBTH) resulted in almost quantitative formation of the arylbutanols 1a-c. Ketols 6 were obtained by hydrolysis of the hydroxyalkyldithianes 5a.