Two enzyme-mediated methods are presented for the preparation of enantiomerically enriched C 2 1, 3-dithiane-1, 3-dioxide. The first takes advantage of a trans stereoselective oxidation by NaIO 4 of enantiomerically pure (R) 1, 3-dithiane-1-oxide obtained by cyclohexanone monooxygenase. In the second method, a kinetic resolution consisting of a domino hydrolysis-decarboxylation process of (±) 2-carbethoxy-1, 3-dithiane-trans-1, 3- ...