The synthesis of D-ribose-2-t from D-arabinose is described and its conversions in aqueous alkali in the presence and absence of oxygen reported. In both situations a significant amount of label is transferred from C-2 to -1 and a relatively small proportion is released to the solvent. It is concluded that hydride transfer is occurring and that enolization, which requires the loss of hydrogen from C-2, is not an obligatory first step in base-catalyzed rearrangements of D-ribose.