Dihydroxylation of 4-substituted 1,2-dioxines: a concise route to branched erythro sugars.

The synthesis of 2-C-branched erythritol derivatives, including the plant sugar (+/-)-2-C-methylerythritol 2, was achieved through a dihydroxylation/reduction sequence on a series of 4-substituted 1,2-dioxines 3. The asymmetric dihydroxylation of 1,2-dioxines was examined, providing access to optically enriched dihydroxy 1,2-dioxanes 4. The synthesized 1,2-dioxanes were converted to other erythro sugar analogues and tetrahydrofurans through controlled cleavage of the endoperoxide linkage.