Selective Degradation of Carbohydrates

Control of degradation reactions of carbohydrates and their applications to short-step syntheses of useful synthetic intermediates by using D-glucono-1, 5-lactone, D-glucopyranuronic acid, and D-glucofuranurono-6, 3-lactone as starting materials are described.The conversion of carbohydrate derivatives to useful synthetic intermediates is successfully achieved by alcoholysis of the degradation products obtained under acetylation conditions.Under acetylation conditions, mono-unsaturated derivatives of D-glucono-1, 5-lactone and D-glucopyranuronic acid, α-pyrone derivatives, butenolide derivatives, a sorbic acid derivative, comanic acid, etc. are obtained from D-glucono-1, 5-lactone, tetraacetate of D-glucopyranuronic acid, and triacetate of D-glucofuranurono-6, 3-lactone in high yields.4, 5-Mono-unsaturated derivative of D-glucopyranuronic acid and α-pyrone derivatives are selectively converted to cyclopentenone derivatives under alcoholysis conditions in the presence of base. On the other hand, 2, 3-mono-unsaturated derivative of D-glucono-1, 5-lactone affords furan derivative under alcoholysis conditions using acid as catalyst.Further, 4-hydroky-4-methoxycarbonyl-2-cyclopentenone, prepared from D-glucono-1, 5-lactone via α-pyrone derivative, is successfully degraded to afford a valuable synthetic intermediate, 1, 3-cyclopentanedione.