2-DEOXY SUGARS .15. 4 ISOMERIC METHYL GLYCOSIDES OF 2-DEOXY-D-RIBO-HEXOSE

Brief treatment of 2-deoxy-d-ribo-hexose in methanol with a small proportion of hydrogen chloride resulted in a 100-% yield of crystalline methyl 2-deoxy-α,β-d-ribo-hexofuranoside in an anomeric ratio of 1:1, fractional recrystallization of which resulted in partial separation of the α-d anomer. The furanoside mixture was converted into its tris-p-nitrobenzoate, and, thence, into crystalline 2-deoxy-3,5,6-tri-O-p-nitrobenzoyl-d-ribo-hexosyl bromide. The new halide underwent methanolysis to yield mainly methyl 2-deoxy-β-O-ribo-hexofuranoside. Methanolysis of 2-deoxy-3,4,6-tri-O-p-nitrobenzoyl-α-d-ribo-hexosyl bromide, followed by deacylation, gave the hitherto-unknown methyl 2-deoxy-β-d-ribo-hexopyranoside. Controlled hydrolysis of methyl 4,6-O-benzylidene-2-deoxy-α-d-ribo-hexopyranoside with acid gave crystalline methyl 2-deoxy-α-d-ribo-hexopyranoside, hitherto reported as a syrup. © 1969.