José Fuentes Mota

Isothiocyanates and cyclic thiocarbamates of α, α′-trehalose, sucrose, and cyclomaltooligosaccharides☆

Abstract 6,6′-Dideoxy-6,6′-diisothiocyanato-α, α′-trehalose (4), 6-deoxy-6-isothiocyanato-α- d -fructofuranose β- d -fructopyranose 1,2′:2,1′-dianhydride (11), 6,6′-dideoxy-6,6′-diisothiocyanatosucrose (16), and per(6-deoxy-6-isothiocyanato)-cyclomaltohexaose (23), -cyclomaltoheptaose (27), and -cyclomaltooctaose (31) have been prepared in high yield by reaction of the corresponding amino sugars with thiophosgene. In the absence of base, all isothiocyanates were stable and could be stored and acetylated without decomposition. In the presence of triethylamine, 6,6′-dideoxy-6,6′-diisothiocyanato-α, α′-trehalose underwent intramolecular cyclisation involving HO-4 to give the corresponding bis(cyclic thiocarbamate). The product of cyclisation at a single glucopyranosyl unit was obtained in the treatment of the above diisothiocyanate with mixed (H+, HO−) ion-exchange resin. Under identical reaction conditions, 6,6′-dideoxy-6,6′-diisothiocyanatosucrose yielded exclusively the product of intramolecular cyclisation at the d -glucopyranosyl moiety, while derivatives of α- d -fructofuranose β- d -fructopyranose 1,2′:2,1′-dianhydride and cyclomaltooligosaccharides remained unchanged.

Regioselective benzoylations of glycopyranosylamines: Synthesis of partially protected glycopyranosyl isothiocyanates

Abstract Regioselective benzoylations of N -(2,2-diethoxycarbonylvinyl)-β- d -galactopyranosylamine ( 1 ) yielded 2,3,6-tri- O - ( 3 ) and 3,6-di- O -benzoyl- N -(2,2-diethoxycarbonylvinyl)-β- d -galactopyranosylamine ( 4 ), whereas, from the β- d - gluco analogue 5 , the 2,3,6-tri- ( 7 ), 3,6-di- ( 8 ), and 2,6-di- O -benzoyl ( 9 ) derivatives were obtained together with the fully esterified compounds ( 2 and 6 ). Treatment of 3 with bromine and of 7 with chlorine gave the 2,3,6-tri- O -benzoyl-β- d -glycopyranosylamine hydrohalides ( 10 and 11 , respectively), which reacted with thiophosgene to afford 2,3,6-tri- O -benzoyl-β- d -galactopyranosyl isothiocyanate ( 12 ) and the β- d - gluco analogue 14 , respectively. 3,6-Di- O -benzoyl-β- d -galactopyranosyl isothiocyanate ( 13 ) was prepared from 4 by successive treatments with bromine and thiophosgene.

Syntheses of d-ribosylamines, d-ribopyranosyl isothiocyanates, and d-ribopyranosylthioureas, and their transformations into heterocyclic compounds☆

Abstract The synthesis of 2,3,5-tri- O -benzoyl-β- d -ribofuranosylamine hydrobromide and 2,3,4,-tri- O -benzoyl-β- d -ribopyranosylamine from d -ribosylamine, via ribosylenamines, is reported. The reaction of 2,3,4-tri- O -benzoyl-β- d -ribopyranosylamine hydrobromide with thiophosgene in a basic medium yields, 2,3,4,-tri- O -benzoyl-α-( 7 ) and -β- d -robopyranosyl isothiocyanate ( 8 ). 5-Methyl-1-(2,3,4,-tri- O -benzoyl-β- d -ribopyranosyl)-4-imidazoline-2-thione was obtained by reaction of 8 with aminoacetone hydrochloride. Treatment of 7 and 8 with phenacylamine hydrochlorides gave the N -phenacyl- N ′ -(2,3,4,-tri- O -benzoyl-α- and -β- d -ribopyranosyl)thioureas. The 5-aryl-2-(2,3,4-tri- O -benzoyl-α- and -β- d -ribopyranosylamino)thiazoles were prepared by cyclodehydration with acetic anhydride and phosphoric acid of the corresponding phenacylribopyranosylthioureas.

Syntheses of β-iodourea derivatives of carbohydrates and glycosylamino-oxazolines

Abstract Syntheses of N -(β- d -glycopyranosyl)- N ′-( trans -2-iodocyclohexyl)ureas ( 3 — 7 , N -(β- d -glucopyranosyl)- N ′-(2-iodo-3,3-dimethylbutyl)ureas ( 8 and 9 ), N -(2-iodo-1,1-diphenylethyl)- N ′-(β- d -xylopyranosyl)-urea ( 10 ), 1,3,4,6-tetra- O -acetyl-2-deoxy-2-[3-( trans -2-iodocyclohexyl)ureido]-α-( 11 ) and -β- d -glucopyranoses ( 12 ), 2-(2,3,4,6,-tetra- O -acetyl-β- d -glucopyranosylamino)- cis -3a,4,5,6,7,7a-hexahydrobenzoxazole ( 15 ), and 4,4-diphenyl-2-(β- d -xylopyranosylamino)-2-oxazoline ( 16 ) are reported.

Glucosylenamines as glycosyl acceptors: synthesis of gentiobiosylenamines

The preparation of 2,3,4-tri-O-benzyl- (3), 2,3,4-tri-O-acetyl- (4), and 2,3,4-tri-O-benzoyl-N-(2,2-diethoxycarbonylvinyl)-6-O-trityl-beta- D-glucopyranosylamine (5) is described. The reaction of 3-5 with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide yields 2,3,4-tri-O-benzyl- (9), 2,3,4-tri-O-acetyl- (10), and 2,3,4-tri-O-benzoyl-N-(2,2-diethoxycarbonylvinyl)-6-O-(2,3,4,6-tet ra-O- acetyl-beta-D-glucopyranosyl)-beta-D-glucopyranosylamine (11), respectively. 2,3,4-Tri-O-benzyl- (6), 2,3,4-tri-O-acetyl- (7), and 2,3,4-tri-O- benzoyl-N-(2,2-diethoxycarbonylvinyl)-beta-D-glucopyranosylamine (8) are also described.

Synthesis of glycofurano[2,1-d]imidazolidin-2-ones

Abstract Several 2-(3-arylureido)-2-deoxyglycopyranoses ( 13–16 ) have been converted into the corresponding 1-aryl-(1,2-dideoxyglycofurano)[2,1- d ]imidazolidin-2-ones ( 17–20 ) by acid-catalyzed cyclization. Acetylation of these compounds gave 1-aryl-(per- O -acetyl-1,2-dideoxyglycofurano)[2,1- d ]imidazolidin-2-ones ( 21–24 ) or 3-acetyl-1-aryl-(per- O -acetyl-1,2-dideoxyglycofurano)[1,2- d ]imidazolidin-2-ones ( 25–28 ) depending on the reaction. 3-Ethyl-1-phenyl-(1,2-dideoxy- d - glycero -β- d - talo -heptofurano)[2,1- d ]imidazolidin-2-one ( 33 ) was obtained by the reaction of 2-deoxy-2-ethylamino- d - glycero -β- d - talo -heptopyranose with phenyl isocyanate, and converted into the tetra-acetate 34 .

Synthesis of N-Hetarylthiourea Derivatives of Carbohydrates

ABSTRACT The syntheses of N-hetaryl (thiazole-2-yl, 2-thiazoline-2-yl, 4,4-diphenyloxazoline-2-yl, cis-3a,4,5,6,7,7a-hexahydrobenzoxazole-2-yl)-N′-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyl) thioureas (1a-1d), N-hetaryl (2-thiazoline-2-yl, 4,4-diphenyloxazoline-2-yl)-N′-(2,3,4,6-tetra-O-benzoyl-β-D-galactopyranosyl) thioureas (2b, 2c) and 1,2,3,4,6-tetra-O-acetyl-2-deoxy-2-[3-(4′, 4′-diphenyl-2′-y1) thioureido]-β-D-glucopyranose (3c) are described. The structures and conformational properties of prepared compounds are based on analytical and spectroscopic (UV, IR, NMR and MS) data.