Oxidation of a branched-chain alditol by acetobacter suboxydans: a stereospecific synthesis of L-dendroketose.

A synthesis of L-dendroketose (5) has been achieved by microbiological oxidation by Acetobacter suboxydans of the branched-chain alditol 2-C-(hydroxy-methyl)-D-erythro-pentitol (4). Treatment of the oxidation product with acetone, copper(II) sulfate, and sulfuric acid afforded the two di-O-isopropylidene-L-dendro-ketose derivatives 6 and 7. Assignment of configuration at the branching carbon atom (C-4) and at the anomeric center in 6 and 7 was made on the basis of the carbon-13 magnetic resonance spectra of these derivatives.