THE PREPARATION AND OXYAMINATION OF 4,6-DI-O-ACETYL-2,3-DIDEOXY-α-D-erythro-HEX-2-ENOPYRANOSYL 4,6-DI-O-ACETYL-2,3-DIDEOXY-α-D-erythro-HEX-2-ENOPYRANOSIDE. SYNTHESIS OF TWO NEW DIAMINO DERIVATIVES OF α-D-MANNOPYRANOSYL α-D-MANNOPYRANOSIDE

Article abstract of DOI:10.1016/0008-6215(84)85021-1

4,6-Di-O-acetyl-2,3-dideoxy-D-erythro-hex-2-enopyranose (4,6-di-O-acetyl-D-pseudoglucal), prepared from 3,4,6-tri-O-acetyl-1,5-anhydro-2-deoxy-D-arabino-hex-1-enitol (tri-O-acetyl-glucal), was condensed, by catalysis with boron trifluoride, with an equivalent of the original glycal, to give crystalline 4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranosyl 4,6-di-O-acetyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside in 40 - 50 percent yield.The dienic disaccharide was cis-oxyaminated with chloramine-T in the presence of osmium tetraoxide, furnishing in 72 percent yield an ca. 2:3.5:1 mixture of the 2,2'-dideoxy-2,2'-di-(p-toluenesulfonamido), 2,3'-dideoxy-2,3'di-(p-toluenesulfonamido), and 3,3'-dideoxy-3,3'-di-(p-toluenesulfonamido) derivatives of α-D-mannopyranosyl α-D-mannopyranoside 4,6,4',6'-tetraacetate.Separation of the mixture, achieved partly before and partly after O-deacetylation, was followed by high-yielding, reductive N-desulfonylations of the individual isomers with sodium in liquid ammonia, to give two new disaccharides, namely, 2-amino-2-deoxy-α-D-mannopyranosyl 2-amino-2-deoxy-α-D-mannopyranoside and its 2,3'-diamino-2,3'-dideoxy isomer, and the known 3,3'-diamino-3,3'-dideoxy isomer.The amino sugars were isolated as their dihydrochlorides, and characterized further by preparation of their di-N-acetyl derivatives.