Synthesis of isotopically labeled 1,3‐dithiane

The 1,3‐dithiane is a protected formaldehyde anion equivalent that could serve as a useful labeled synthon. We report a facile synthesis of 1,3‐[2‐ 13 C]‐ and 1,3‐[2‐ 13 C, 2‐ 2 H 2 ]dithiane in two steps from [ 13 C]‐ or [ 13 C, 2 H 3 ]methyl phenyl sulfoxide. We have previously reported the high yield synthesis of [ 13 C]methyl phenyl sulfide from [ 13 C]MEOH and the oxidation of [ 13 C]methyl phenyl sulfide to [ 13 C]methyl phenyl sulfoxide. Here, we describe the facile exchange of deuterium from 2 H 2 O into [ 13 C]methyl phenyl sulfoxide to yield [ 13 C, 2 H 3 ]methyl phenyl sulfoxide. Thus, from [ 13 C]MEOH and 2 H 2 O, all possible C2 stable isotopomers of 1,3‐dithiane are available. Our synthetic route is also amenable to preparation of radiolabeled 1,3‐dithianes. Copyright © 2014 John Wiley & Sons, Ltd.