Kerstin D. Philips

The nitrous acid deamination of glycosides and acetates of 2-amino-2-deoxy-D-glucose

A procedure is described for the nitrous acid deamination of 2-amino-2-deoxy-D-glucose hydrochloride (1), and reduction of the product with buffered borohydride, to afford crystalline 2,5-anhydro-D-mannitol (3) in 71% yield. Similar treatment of the methyl α-pyranoside (4) of 1 gives 59% of crystalline 3, and the same product is obtained in 44% yield from 1,3,4,6-tetra-O-acetyl-2-amino-2-deoxy-α(or β)-D-glucopyranose hydrochloride (5 or 6) by the deamination-reduction sequence with subsequent deacetylation. These results provide a model, for a nonhydrolytic, depolymerization technique for structural characterization of glycosaminoglycans.

Diazo Derivatives of Sugars. Synthesis of methyl 2-deoxy-2-Diazo-d-arabino-Hexonate, Its Behaviour on Photolysis and Thermolysis, and Conversion into a Pyrazole Derivative

Abstract The action of nitrous acid on methyl 2-amino-2-deoxy- d -gluconate hydrochloride ( 5 ) and acetylation of the product gives methyl 3,4,5,6-tetra- O -acetyl-2deoxy-2-diazo- d - arabino -hexonate ( 6 ); 4,6- O -benzylidene analogs of the methyl ( 4 ) and ethyl ( 3 ) esters are similarly prepared. Photolysis of the diazo sugar 6 in isopropyl alcohol gives mainly methyl 3,4,5,6-tetra- O -acetyl-2-deoxy- d - arabino -hexonate ( 13 ) and a small proportion of methyl 4,5,6-tri- O -acetyl-2,3-dideoxy- trans ,- d - erythro -hex2-enoate ( 14 ), whereas photolysis of 6 in methanol gave a cis,trans mixture of methyl 3,4,5,6-tetra- O -acetyl-2-deoxy- d -erythro-hex-2-enoate ( 10 ); the same mixture ( 10 ) of enol acetates was obtained by thermolysis of 6 . The diazo sugar 6 underwent cycloaddition with phenylacetylene to give a crystalline ( R or S )-3-( d - arabino -tetraacetoxybutyl)-3-methoxycarbonyl-5-phenyl-3 H -pyrazole ( 9 ) in 85% yield.

Synthesis of 1,6-anhydro derivatives of 2-amino-2-deoxy-β-D-talopyranose and 4-amino-4-deoxy-β-D-talopyranose

Abstract The oxime ( 2 ) of 1,6-anhydro-3,4- O -isopropylidene-β- D - lyxo -hexopyranos-2-ulose ( 1 ) in aqueous hydrochloric acid is reduced stereospecifically by hydrogen and a platinum catalyst, with concomitant hydrolysis of the O -isopropylidene group, to give 2-amino-1,6-anhydro-2-deoxy-β- D -talopyranose hydrochloride ( 3 ) in high yield. Hydrolysis of the anhydro sugar 3 under more vigorous conditions gave crystalline 2-amino-2-deoxy-α- D -talopyranose hydrochloride ( 4 ). In aqueous solution, the amino sugar 4 exists as a 1:2 mixture of the α and β- D -pyranose anomers. Reduction of 1,6-anhydro-2,3- O -isopropylidene-β- D - lyxo -hexopyranos-4-ulose oxime ( 5 ) in aqueous hydrochloric acid, with hydrogen over platinum, also occurred stereospecifically, to give a crystalline product formulated as 4-amino-1,6-anhydro-4-deoxy-β- D -talopyranose hydrochloride ( 6 ), which was further characterized as the peracetylated derivative 7 . Attempted hydrolysis of 6 to give 4-amino-4-deoxy- D -talose hydrochloride ( 8 ) gave only unchanged 6 and tarry products, presumably because the free 4-amino sugar derivative 8 undergoes rapid destruction in the acid solution by way of a pyrrole derivative.