Synthesis of a trehalose homolog, 6-deoxy-α-d-gluco-heptopyranosyl 6-deoxy-α-d-gluco-heptopyranoside, and the corresponding bis(heptosiduronic acid)

✍ Scribed by Hans H. Baer; Roger L. Breton; Yaping Shen

• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 910 KB
• Volume: 200
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(90)84204-8

✦ Synopsis

ABSTRAC-I

Crystalline 6-deoxy-a-D-gluco-heptopyranosyl 6-deoxy-a-o-gluco-heptopyranoside ( 8) and (6-deoxy-a-D-gluco-heptopyranosyluronic acid) 6-deoxy-a-D-gluco-heptopyranosiduronic acid (7) were synthesized from a,a-trehalose (1). Reaction of2,3,4,2',3',4'-hexa-O-acetyl-6,6'-di-O-tosyl-a,a-trehalose with sodium dicarbonylcyclopentadienyliron, followed by oxidative hydrolysis or methanolysis, gave the 2,3,4,2',3',4'-hexa-acetate of 7 or its dimethyl ester, respectively. O-Deacetylation (Zempltn) then gave 7 and its dimethylester.

Reduction of the hexa-O-acetyldicarboxylic acid with borane axolane complex yielded 8.

Alternatively, cyanide displacement of hexa-O-acetyl-a,a-trehalose. 6,6'-ditriflate gave the dinitrile hexaacetate of 7, which was O-deacetylated and then hydrolyzed with alkaline hydrogen peroxide to yield 7. 2,3,4,2',3',4'-Hexa-O-benzyl-a,a-trehalose6,6'-ditriflatewas similarlyconvertedinto thedinitrile, whichwas hydrolyzed to the corresponding diamide. Treatment of the 2,3,4,2',3',4'-hexa-O-acetyl-a,a-trehalosuronic acid 16 with thionyl chloride followed by diazomethane gave a crystalline bisdiazoketone which, however, failed to produce the expected bis(heptosiduronic acid) on attempted Wolff rearrangement.