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• 604-68-2 α-D-glucopyranose peracetylate 

Relevant academic research and scientific papers

Esterase-catalysed regioselective 6-deacylation of hexopyranose per-acetates, acid-catalysed rearrangement to the 4-deprotected products and conversions of these into hexose 4- and 6-sulfates

The esterase from Rhodosporidium toruloides has been used to catalyse the hydrolysis of a series of per-acetylated α-D-hexopyranoses and α-D-hexopyranosides. Per-acetylated glucose 4, mannose 6, N-acetylgalactosamine 8, galactose 10, methyl α-D-glucoside 12, methyl α-D-mannoside 14 and methyl α-D-galactoside 16 have been selectively cleaved at the C-6 position by the esterase to give the 6-OH derivatives 5, 7, 9, 11, 13, 15 and 17. Acid-catalysed rearrangement of acetates 5, 7, 13, 15, 11, 17 and 9 with 4→6 acetyl migration gives the corresponding 4-deprotected derivatives 22-28, respectively. Hydrolyses of β-D-glucose pentaacetate 20 and α-D-lactose octaacetate 21 have been attempted, but no hydrolyses have been observed. 1,2,3,6-TetraacyIated α-D-hexopyranoses 3 and 22, derivatives of N-acetylglucosamine and glucose respectively, and 2,3,6-triacetylated α-D-hexopyranosides 24 and 25, derivatives of glucose and mannose, respectively, have been hydrolysed by the esterase to the corresponding 4,6-dihydroxy acetates 29, 18, 30 and 31. Acylation of methyl α-D-glucopyranoside 32 catalysed by the esterase provides the C-6 monoacetate 33 and the C-3 monoacetate 34 in 4 and 5% yield, respectively. The sodium salts of N-acetylglucosamine, glucose, N-acetylgalactosamine, galactose and mannose 6-sulfates 38-42, respectively, are prepared in two steps from the 6-deacetylated hexopyranoses 2, 5, 9, 11 and 7, respectively. The sodium salts of N-acetylglucosamine, glucose and mannose 4-sulfates 43-45, respectively, are prepared in two steps from the 4-deacetylated precursors 3, 22 and 26 which are obtained via acid catalysed 4→6 acyl migration of compounds 2, 5 and 7.

Enzymes in Carbohydrate Synthesis: Lipase-Catalyzed Selective Acylation and Deacylation of Furanose and Pyranose Derivatives

A number of furanose and pyranose derivatives were selectively acylated and deacylated on a preparative scale in lipase-catalyzed reactions.The primary hydroxyl functions of the methyl furanosides of D-ribose, D-arabinose, D-xylose, and 2-deoxy-D-ribose were selectively acetylated by crude porcine pancreatic lipase in tetrahydrofuran by using 2,2,2-trifluoroethyl acetate as the acyl donor.Selective deacetylations of the primary hydroxyl functions in the peracetylated methyl furanosides of D-ribose, D-arabinose, D-xylose, and 2-deoxy-D-ribose were best accomplished in a 9:1 solution of 0.1 N phosphate buffer (pH 7) and N,N-dimethylformamide using Candida cylindracea lipase.Selective cleavage of the 1-O-acetyl groups from 1,2,3,5-tetra-O-acetyl-D-ribose and -D-xylose were similarly accomplished with Aspergillus niger lipase.Similar regioselectivites were observed in the pyranose series.The Candida lipase was found to be the best for selective deacylation of the primary position from the peracylated methyl pyranosides, and porcine pancreatic lipase was the best for selective hydrolysis of the 1-O-acetyl groups from peracetylated pyranoses.