Stereoselective Chemo-Enzymatic Approaches to the Synthesis of C₂ 1,3-Dithiane-1,3-dioxide

Abstract

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-dioxide is described. The target molecule is obtained with enantiomeric excesses up to 90%.

Keywords:

• C ₂-symmetric bis(sulfoxides)
• cyclohexanone monooxygenase
• 1,3-dithiane-trans-1,3-dioxide
• kinetic resolution
• pig liver esterase
• subtilisin Carlsberg

Dedicated to Professor Marian Mikołajczyk, CBMiM PAN in Łódź, Poland, on the occasion of his 70th birthday.

Notes

^a Determined by ¹H NMR spectroscopy.

^b Determined by HPLC.

^c Pig liver esterase.