Ryohei Yamasaki

Derivatives of sucrose 3′,4′-epoxide

Abstract A facile, one-pot synthesis of α- d -glucopyranosyl 3,4-anhydro-β- d -tagatofuranoside (1) from sucrose in good yield is reported. Derivatives of 1 can also be obtained from 4,6:2,1′-di-O-isopropylidenesucrose and from 2,3,6,1′,6′-penta-O-benzoylsucrose by treatment with triphenylphosphine and diethyl azodicarboxylate. The n.m.r. spectra (13C,1H) and conformation of derivatives of 1 are discussed. A new anhydrosucrose (1′,4′) is reported.

Formation of 3′,6′-anhydrosucrose by Mitsunobu dehydration of sucrose

Le traitement du saccharose avec la triphenylphosphine et le azodicarboxylate de diethyle dans le DMF (reaction de Mitsunobu) fournit lanhydro-3,4 saccharose et le compose presuppose lanhydro-1,4 saccharose. Lauteur montre ici par letude des spectres RMN que ce second compose est en fait le saccharose anhydro-3,6

d-fructose derivatives modified at C-4 by direct displacementand by oxirane opening

Abstract The epoxide ring of methyl 3,4-anhydro- β - d -tagatofuranoside is opened byattack of nucleophiles at C-4 to yield derivatives of D-fructose. Treatment of 2,3- O -isopropylidene-1,6-di- Op -tolylsulfonyl- β - d -fructofuranose with sulfuryl chloride resulted in attack at C-6, not C-4. 2,3- O -Isopropylidene-1,6-di- O - p -tolylsulfonyl- β - d -tagatofuranose behaved normally with this reagent. Methyl 4-deoxy- β - d - threo -hexulofuranoside was not hydrolysed by invertase.

Epoxidations with triphenylphosphine and diethyl azodicarboxylate. Part 1. Synthesis of methyl 3,4-anhydro-D-tagatofuranosides

Treatment of methyl β-D-fructofuranoside (6) with triphenylphosphine and diethyl azodicarboxylate in dimethylformamide gives a high yield of methyl 3,4-anhydro-β-D-tagatofuranoside (5); no blocking of the hydroxy-groups at C-1 and C-6 is necessary. The structure of the product was confirmed by an X-ray structural study of its 1,6-bis-O-(p-tolylsulphonyl) derivative and by an unambiguous synthesis. A similar reaction of methyl α-D-fructofuranoside yielded the 3,4-anhydro-α-D-tagatofuranoside. The reaction mechanism is discussed.

Epoxidation using triphenylphosphine–diethyl azodicarboxylate: synthesis of methyl 3,4-anhydro-α- and -β-D-tagatofuranosides

Facile syntheses of the title compounds have been achieved by the one-step reaction of methyl α- or β-D-fructofuranoside with triphenylphosphine and diethyl azodicarboxylate in dimethylformamide; no blocking groups were necessary.