Methylribose → 6-Deoxyaltritol

As shown in FIG. 23, first, 6-deoxy L-psicose was prepared from L-rhamnose, using L-rhamnose isomerase and D-tagatose 3-epimerase (The Annual Meeting of the Japan Society of Bioscience, Biotechnology and Agrochemistry 2007). As a consequence of the hydrogenation with a nickel catalyst under high-pressure conditions, a mixture of 1-deoxy D-allitol (6-deoxy-L-allitol) and 1-deoxy D-talitol (6-deoxy-L-tallitol) was obtained (FIGS. 24 and 26). The mixture as a substrate was subjected to a bacterial cell reaction with the bacterial strain IK7 (NITE BP-271) of the genus Enterobacter (FIGS. 25 and 27). Consequently, only 1-deoxy D-allitol was selectively oxidized to 1-deoxy D-psicose. Almost no reduction of the total weight of both the substrates with the bacterial strain IK7 of the genus Enterobacter was observed. The productivity of 1-deoxy D-psicose from 1-deoxy D-allitol was about 90%. The reaction products were separated from each other. Consequently, 1-deoxy D-psicose and 1-deoxy D-talitol were obtained individually as pure products. A photograph of the crystal of the resulting 6-deoxy L-psicose is shown in FIG. 28. The product was identified by comparison with the chemically synthesized 1-deoxy D-psicose and confirmed on the basis of the coincidence of the 13C NMR spectra (FIG. 29) of the two and the optical rotation degrees of the two.