PubMed:3401878 JSONTXT

{"project":"sentences","denotations":[{"id":"TextSentencer_T1","span":{"begin":0,"end":98},"obj":"Sentence"},{"id":"TextSentencer_T2","span":{"begin":99,"end":486},"obj":"Sentence"},{"id":"TextSentencer_T3","span":{"begin":487,"end":762},"obj":"Sentence"},{"id":"TextSentencer_T4","span":{"begin":763,"end":959},"obj":"Sentence"},{"id":"TextSentencer_T5","span":{"begin":960,"end":1086},"obj":"Sentence"},{"id":"TextSentencer_T6","span":{"begin":1087,"end":1239},"obj":"Sentence"},{"id":"TextSentencer_T7","span":{"begin":1240,"end":1460},"obj":"Sentence"},{"id":"TextSentencer_T8","span":{"begin":1461,"end":1617},"obj":"Sentence"},{"id":"T1","span":{"begin":0,"end":98},"obj":"Sentence"},{"id":"T2","span":{"begin":99,"end":486},"obj":"Sentence"},{"id":"T3","span":{"begin":487,"end":762},"obj":"Sentence"},{"id":"T4","span":{"begin":763,"end":959},"obj":"Sentence"},{"id":"T5","span":{"begin":960,"end":1086},"obj":"Sentence"},{"id":"T6","span":{"begin":1087,"end":1239},"obj":"Sentence"},{"id":"T7","span":{"begin":1240,"end":1460},"obj":"Sentence"},{"id":"T8","span":{"begin":1461,"end":1617},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"Synthesis of methyl 6''-deoxy-6'-fluoro-alpha-isomaltoside and of the corresponding trisaccharide.\nMethyl 6-O-(6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl)-2,3,4-tri- O-benzyl-alpha-D-glucopyranoside (5) was formed with high stereoselectivity when the condensation of methyl 2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl (1) with 6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl chloride in ether was promoted with silver perchlorate in the presence of 2,4,6-trimethylpyridine. O-Deacetylation of 5, followed by treatment of the formed 6, containing only HO-6' unsubstituted, with diethylaminosulfur trifluoride (DAST) or dimethylaminosulfur trifluoride (methyl DAST) gave the per-O-benzyl derivative (9) of methyl 6'-deoxy-6'-fluoro-alpha-isomaltoside. Compound 9 was also obtained by condensation of 1 with 2,3,4-tri-O-benzyl-6-deoxy-6-fluoro-beta-D-glucopyranosyl fluoride (4) in the presence of silver perchlorate and anhydrous stannous chloride. The fully benzylated methyl alpha-glycoside (15) of 6-deoxy-6-fluoro-isomaltotriose, was obtained by condensation of 6 with 4. Hydrogenolysis of 9 and 15 gave the methyl alpha-glycosides of isomaltose and isomaltotriose fluorinated at C-6 of their (nonreducing) D-glucosyl group. Fluoride-ion displacements involving DAST and methyl DAST gave practically identical results, but mixtures arising from reactions involving the latter reagent were lighter-colored and easier to resolve by chromatography. The isolation of methyl alpha-glycosides of 6'-deoxy-6'-fluorogentiobiose and of 6'-O-(6-deoxy-6-fluoro-beta-D-glucopyranosyl) isomaltose is also described."}

{"project":"GlyCosmos15-Glycan","denotations":[{"id":"T1","span":{"begin":1150,"end":1160},"obj":"Glycan"},{"id":"T2","span":{"begin":1588,"end":1598},"obj":"Glycan"}],"attributes":[{"id":"A1","pred":"glycosmos_id","subj":"T1","obj":"https://glycosmos.org/glycans/show/G36281WI"},{"id":"A3","pred":"image","subj":"T1","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G36281WI"},{"id":"A2","pred":"glycosmos_id","subj":"T2","obj":"https://glycosmos.org/glycans/show/G36281WI"},{"id":"A4","pred":"image","subj":"T2","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G36281WI"}],"text":"Synthesis of methyl 6''-deoxy-6'-fluoro-alpha-isomaltoside and of the corresponding trisaccharide.\nMethyl 6-O-(6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl)-2,3,4-tri- O-benzyl-alpha-D-glucopyranoside (5) was formed with high stereoselectivity when the condensation of methyl 2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl (1) with 6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl chloride in ether was promoted with silver perchlorate in the presence of 2,4,6-trimethylpyridine. O-Deacetylation of 5, followed by treatment of the formed 6, containing only HO-6' unsubstituted, with diethylaminosulfur trifluoride (DAST) or dimethylaminosulfur trifluoride (methyl DAST) gave the per-O-benzyl derivative (9) of methyl 6'-deoxy-6'-fluoro-alpha-isomaltoside. Compound 9 was also obtained by condensation of 1 with 2,3,4-tri-O-benzyl-6-deoxy-6-fluoro-beta-D-glucopyranosyl fluoride (4) in the presence of silver perchlorate and anhydrous stannous chloride. The fully benzylated methyl alpha-glycoside (15) of 6-deoxy-6-fluoro-isomaltotriose, was obtained by condensation of 6 with 4. Hydrogenolysis of 9 and 15 gave the methyl alpha-glycosides of isomaltose and isomaltotriose fluorinated at C-6 of their (nonreducing) D-glucosyl group. Fluoride-ion displacements involving DAST and methyl DAST gave practically identical results, but mixtures arising from reactions involving the latter reagent were lighter-colored and easier to resolve by chromatography. The isolation of methyl alpha-glycosides of 6'-deoxy-6'-fluorogentiobiose and of 6'-O-(6-deoxy-6-fluoro-beta-D-glucopyranosyl) isomaltose is also described."}

{"project":"Glycan-GlyCosmos","denotations":[{"id":"T1","span":{"begin":1150,"end":1160},"obj":"Glycan"},{"id":"T2","span":{"begin":1588,"end":1598},"obj":"Glycan"}],"attributes":[{"id":"A1","pred":"glycosmos_id","subj":"T1","obj":"https://glycosmos.org/glycans/show/G36281WI"},{"id":"A3","pred":"image","subj":"T1","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G36281WI"},{"id":"A2","pred":"glycosmos_id","subj":"T2","obj":"https://glycosmos.org/glycans/show/G36281WI"},{"id":"A4","pred":"image","subj":"T2","obj":"https://api.glycosmos.org/wurcs2image/latest/png/binary/G36281WI"}],"text":"Synthesis of methyl 6''-deoxy-6'-fluoro-alpha-isomaltoside and of the corresponding trisaccharide.\nMethyl 6-O-(6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl)-2,3,4-tri- O-benzyl-alpha-D-glucopyranoside (5) was formed with high stereoselectivity when the condensation of methyl 2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl (1) with 6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl chloride in ether was promoted with silver perchlorate in the presence of 2,4,6-trimethylpyridine. O-Deacetylation of 5, followed by treatment of the formed 6, containing only HO-6' unsubstituted, with diethylaminosulfur trifluoride (DAST) or dimethylaminosulfur trifluoride (methyl DAST) gave the per-O-benzyl derivative (9) of methyl 6'-deoxy-6'-fluoro-alpha-isomaltoside. Compound 9 was also obtained by condensation of 1 with 2,3,4-tri-O-benzyl-6-deoxy-6-fluoro-beta-D-glucopyranosyl fluoride (4) in the presence of silver perchlorate and anhydrous stannous chloride. The fully benzylated methyl alpha-glycoside (15) of 6-deoxy-6-fluoro-isomaltotriose, was obtained by condensation of 6 with 4. Hydrogenolysis of 9 and 15 gave the methyl alpha-glycosides of isomaltose and isomaltotriose fluorinated at C-6 of their (nonreducing) D-glucosyl group. Fluoride-ion displacements involving DAST and methyl DAST gave practically identical results, but mixtures arising from reactions involving the latter reagent were lighter-colored and easier to resolve by chromatography. The isolation of methyl alpha-glycosides of 6'-deoxy-6'-fluorogentiobiose and of 6'-O-(6-deoxy-6-fluoro-beta-D-glucopyranosyl) isomaltose is also described."}

{"project":"GlyCosmos15-Sentences","blocks":[{"id":"T1","span":{"begin":0,"end":98},"obj":"Sentence"},{"id":"T2","span":{"begin":99,"end":486},"obj":"Sentence"},{"id":"T3","span":{"begin":487,"end":762},"obj":"Sentence"},{"id":"T4","span":{"begin":763,"end":959},"obj":"Sentence"},{"id":"T5","span":{"begin":960,"end":1086},"obj":"Sentence"},{"id":"T6","span":{"begin":1087,"end":1239},"obj":"Sentence"},{"id":"T7","span":{"begin":1240,"end":1460},"obj":"Sentence"},{"id":"T8","span":{"begin":1461,"end":1617},"obj":"Sentence"}],"text":"Synthesis of methyl 6''-deoxy-6'-fluoro-alpha-isomaltoside and of the corresponding trisaccharide.\nMethyl 6-O-(6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl)-2,3,4-tri- O-benzyl-alpha-D-glucopyranoside (5) was formed with high stereoselectivity when the condensation of methyl 2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl (1) with 6-O-acetyl-2,3,4-tri-O-benzyl-alpha-D-glucopyranosyl chloride in ether was promoted with silver perchlorate in the presence of 2,4,6-trimethylpyridine. O-Deacetylation of 5, followed by treatment of the formed 6, containing only HO-6' unsubstituted, with diethylaminosulfur trifluoride (DAST) or dimethylaminosulfur trifluoride (methyl DAST) gave the per-O-benzyl derivative (9) of methyl 6'-deoxy-6'-fluoro-alpha-isomaltoside. Compound 9 was also obtained by condensation of 1 with 2,3,4-tri-O-benzyl-6-deoxy-6-fluoro-beta-D-glucopyranosyl fluoride (4) in the presence of silver perchlorate and anhydrous stannous chloride. The fully benzylated methyl alpha-glycoside (15) of 6-deoxy-6-fluoro-isomaltotriose, was obtained by condensation of 6 with 4. Hydrogenolysis of 9 and 15 gave the methyl alpha-glycosides of isomaltose and isomaltotriose fluorinated at C-6 of their (nonreducing) D-glucosyl group. Fluoride-ion displacements involving DAST and methyl DAST gave practically identical results, but mixtures arising from reactions involving the latter reagent were lighter-colored and easier to resolve by chromatography. The isolation of methyl alpha-glycosides of 6'-deoxy-6'-fluorogentiobiose and of 6'-O-(6-deoxy-6-fluoro-beta-D-glucopyranosyl) isomaltose is also described."}