Branched-chain Sugars. XXII. Synthesis of Benzyl 2,3-Di-<i>O</i>-benzyl- and 2,3-<i>O</i>-Methylene-β-L-<i>threo</i>-pentopyranosid-4-uloses, and the Corresponding 6-Deoxy-α-D-<i>xylo</i>-hexopyranosid-4-uloses
The title compounds were synthesized from L-arabinose and D-glucose as intermediates to a few naturally occuring branched-chain sugars. Oxidation conditions of precursors to the corresponding 4-uloses were examined.