A new synthesis of d-psicose (d-ribo-hexulose)

Bioproduction ofD-Psicose from Allitol withEnterobacter aerogenesIK7: A New Frontier in Rare Ketose Production

“…There have been few reports on the chemical synthesis of D-psicose. It can be produced from D-fructose using molybdate ion catalyst, 10) or synthesized from 1,2:4,5-di-O-isopropylidene--D-fructopyranose 11) or by boiling in ethanol and triethylamine. 12) Biotransformation is finding increasingly wide-spread application not only in academia but also in industry.…”

Organic chemistry section:

“…In contrast to these results for the acetals (1)(2)(3)(4) of the aldopentoses, the sole 2-pentulose acetal for which a detailed study was made, namely, 2 , 3-0-isopropylidene-3-Dthreo -pentulofuranose (9) 3 required 8 hr for complete hydrolysis.…”

“…arabinopyranose (1-e, the enantiomorph of 1), 1,2 : 3 , 5-di-0-isopropylidene-a-g-xylofuranose (2), 2 ,3-0-isopropylidene-a-D-xylofuranose (3), and 2 , 3-0-isopropylidene-D-ribofuranose (4)] are completely hydrolyzed to the corresponding free sugar within 2 hr at 65°C, regardless of (a) the presence of a pyranoid (1) or a furanoid ring (2)(3)(4), or (b) the positions of attachment of the isopropylidene groups . However, as previously noted [2], hydrolysis of 2 to 1,2-0-isopropylidenea-g-xylofuranose is complete in 40 min at 25°C, but hydrolysis of 1-e to a monoisopropy lidene acetal, at either 25 1-4, the m-dioxane ring c is -fused at C-3,C-4 of 2 is much less stable than any of the cis -fused 1, 3-dioxolane rings.…”

Organic chemistry section:

“…One-step aromatization of m^jo-inositol (5) (a cyclohexanehexol) , following treatment with methyl sulfoxide-acetic anhydride in the presence of pyridine, has been reported previously [7]; the product, namely, pentaacetoxybenzene (,6b) was isolated in about 50 In order to test the general applicability of this procedure [7] 5 compound 5 was separately treated with propionic, butyric, and isobutyric anhydrides [8]. As expected, compound 5 was converted into the corresponding fatty acid esters of benzenepentol (,6a Attempts with all known acetylation procedures were incapable of providing an isolable acetate of that compound.…”

“…McDonald [50] found mp 101-102°C; [ and co-workers [51]. We have repeated their method of isolation of compound 2 3 and find it satisfactory.…”