ChemInform Abstract: Isopropylidenation of L-Arabinose N,N-Dimethylhydrazone.

ChemInform Abstract

Direct isopropylidenation of the title compound was studied. Four major products (I), (IV), (VI) and (VII) were produced in varying ratios depending upon the conditions as shown for example in the scheme. The dimethoxypropane (V) and H₂SO₄ at 20°C gave the best yield of the desired (IV). Attempted aldol condensations directly on (IV) with paraformaldehyde were unsuccessful. (IV) was readily hydrolyzed to the corresponding protected aldehyde (VIII) which underwent an aldol-Cannizzaro reaction to give the branched chain pentitol (X) in high yield.