A New Base-induced Rearrangement of Hexopyranuronic Acid Derivatives with Solvent Participation. Preliminary communication
✍ Scribed by Joseph Kiss; Wolf Arnold
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- German
- Weight
- 213 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
Abstract
Uronates (as pyranosides or furanosides) bearing good leaving groups (mesylates, tosylates, phosphates, etc.) in β‐ and γ‐position to the alkoxycarbonyl group (e.g. 1) give the epimeric β,γ‐unsaturated α‐alkoxy‐β,γ‐dideoxy‐uronates 4 by treatment with organic or inorganic bases in alcoholic solution.
This new rearrangement of carbohydrates was exemplified with a D‐glucosamine derivative: an alcoholic solution of methyl [O (1)‐benzyl‐2‐C‐benzyloxyformamido]‐2‐deoxy‐3,4‐bis [O (methylsulfonyl)]‐α‐D‐glucopyranosiduronate 1 in the presence of KOH, DBU, or strong alkaline anion exchange resins gave the C(5)‐epimeric mixture of methyl [benzyl‐2‐[C‐(benzyloxy)formamido]‐2,3,4‐trideoxy‐5‐alkoxy‐α‐D‐glycero‐hex‐3‐enopyranosid]uronates (4a–e). The reaction took place with stoichiometric solvent participation using primary, secondary or tertiary alcohols. Other polyfunctional compounds having an alcoholic hydroxyl group can also participate in this reaction. Compounds obtained have been characterized in the form of their crystalline amides.