Abstract The Baker's yeast reduction of 1-(1, 3-dithian-2-yl)-1, 2-propanedione gave highly enantio-and diastereoselectively (S)-(+)-(1-1, 3-dithian-2-yl)-2-hydroxy-1-propanone or (1S, 23-(+)-(1)-(1, 3-dithian-2-yl-1, 2-propanediol, depending on the reaction time. The hydroxy ketone was reduced with diisobutylaluminum hydride to give (1R, 2S)-1-(1, 3-dithian-2-yl)-1, 2-propanediol with high diastereoselectivity. The former (1S, 2S)-diol was converted into L ...