1-Deoxy-d-xylulose:  Synthesis Based on Molybdate-Catalyzed Rearrangement of a Branched-Chain Aldotetrose

1-Deoxy-d-xylulose has been prepared in seven steps and ∼21% overall yield from 2,3-O-isopropylidene-d-erythrono-1,4-lactone. The key reaction involves transformation of a branched-chain aldotetrose to the 1-deoxy-2-ketopentose catalyzed by molybdic acid. Other branched-chain aldotetroses containing bulkier substituents at C2 also engage in the conversion, suggesting routes to protected 2-ketoses and α-ketoacids/esters. This synthetic route mimics reactions of the non-mevalonate isoprenoid pathway in plants and bacteria.