Straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides
(Chemical Equation Presented) 3,4-Anhydro hexopyranosides have been prepared by diastereoselective epoxidation of derivatives of 2-propyl 3,4-dideoxy-α-D-erythro-hex-3-enopyranoside (5), selectively protected at HO-2 and HO-6. The allylic group at C-2, in 5 and derivatives, plays a critical role in...
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todo:paper_00223263_v73_n18_p7224_Manzano2023-10-03T14:31:27Z Straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides Manzano, V.E. Uhrig, M.L. Varela, O. Chemical reactions Derivatives Epoxidation Polysaccharides Silicones Sugar (sucrose) Sulfur Synthesis (chemical) Cellobiose Chemical equations D-glucopyranose Diastereo-selectivity Diastereoselective epoxidation Erythro Facial selectivity Laminarabiose M-chloroperbenzoic acid Oxirane Ring-opening Tert-butyldimethylsilyl Thiodisaccharide Sugars 2 propyl 3,4 dideoxy alpha dextro erythrohex 3 enopyranoside 2 propyl 6 o acetyl 3,4 anhydro alpha dextro allopyranoside 3 chloroperbenzoic acid allyl compound cellobiose disaccharide epoxide ethylene oxide derivative per o acetyl 1 thio beta dextro glucopyranose peracetic acid pyranoside silane derivative sugar sulfur derivative tert butyldimethylsilyl thiol unclassified drug acetylation article chemical bond chemical structure diastereoisomer epoxidation proton nuclear magnetic resonance reaction analysis ring opening synthesis Carbohydrate Conformation Carbohydrates Disaccharides Epoxy Compounds Stereoisomerism (Chemical Equation Presented) 3,4-Anhydro hexopyranosides have been prepared by diastereoselective epoxidation of derivatives of 2-propyl 3,4-dideoxy-α-D-erythro-hex-3-enopyranoside (5), selectively protected at HO-2 and HO-6. The allylic group at C-2, in 5 and derivatives, plays a critical role in the facial selectivity of the epoxidation reaction. Thus, the free HO-2 in 3 (the 6-O-acetyl derivative of 5) directs the attack of m-chloroperbenzoic acid from the more hindered α face of the molecule to give 2-propyl 6-O-acetyl-3,4-anhydro-α-D-allopyranoside (7) accompanied by the β epoxide 6 as a very minor product. Reverse diastereoselectivity has been obtained when the HO-2 in 3 was substituted by a bulky tert-butyldimethylsilyl (TBS) group. In this case, the major isomer was the 2-O-TBS derivative of 6 (α-D-galacto configuration). The ring-opening of sugar epoxides by nucleophilic per-O-acetyl-1-thio-β-D-glucopyranose (11) was employed as a convenient approach to the synthesis of (1→3)-and (1→4)- thiodisaccharides. For example, ring-opening of the oxirane 7 by 11 led to the expected regioisomeric per-O-acetyl thiodisaccharides β-D-Glc-S-(1→3)- 4-thio-α-D-Glc-O-iPr (12) and β-D-Glc-S-(1→4)4-thio-α-D- Gul-O-iPr (13). Regioselectivity in the construction of the (1→4)- thioglycosidic linkage could be achieved by hindering C-3 of the 3,4-anhydro sugar with a bulky silyloxy group at the vicinal C-2. For instance, coupling of the 2-O-TBS derivative of 7 with 11 led regioselectively to the protected thiodisaccharide β-D-Glc-S-(1→4)-4-thio-α-D-Glc-O-iPr (27). The utility of the approach was demonstrated through the synthesis of sulfur-linked analogues of naturally occurring (laminarabiose and cellobiose) and non-natural disaccharides (i.e., β-D-Glc-(1→4)-α-D-Gul). © 2008 American Chemical Society. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00223263_v73_n18_p7224_Manzano |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Chemical reactions Derivatives Epoxidation Polysaccharides Silicones Sugar (sucrose) Sulfur Synthesis (chemical) Cellobiose Chemical equations D-glucopyranose Diastereo-selectivity Diastereoselective epoxidation Erythro Facial selectivity Laminarabiose M-chloroperbenzoic acid Oxirane Ring-opening Tert-butyldimethylsilyl Thiodisaccharide Sugars 2 propyl 3,4 dideoxy alpha dextro erythrohex 3 enopyranoside 2 propyl 6 o acetyl 3,4 anhydro alpha dextro allopyranoside 3 chloroperbenzoic acid allyl compound cellobiose disaccharide epoxide ethylene oxide derivative per o acetyl 1 thio beta dextro glucopyranose peracetic acid pyranoside silane derivative sugar sulfur derivative tert butyldimethylsilyl thiol unclassified drug acetylation article chemical bond chemical structure diastereoisomer epoxidation proton nuclear magnetic resonance reaction analysis ring opening synthesis Carbohydrate Conformation Carbohydrates Disaccharides Epoxy Compounds Stereoisomerism |
| spellingShingle |
Chemical reactions Derivatives Epoxidation Polysaccharides Silicones Sugar (sucrose) Sulfur Synthesis (chemical) Cellobiose Chemical equations D-glucopyranose Diastereo-selectivity Diastereoselective epoxidation Erythro Facial selectivity Laminarabiose M-chloroperbenzoic acid Oxirane Ring-opening Tert-butyldimethylsilyl Thiodisaccharide Sugars 2 propyl 3,4 dideoxy alpha dextro erythrohex 3 enopyranoside 2 propyl 6 o acetyl 3,4 anhydro alpha dextro allopyranoside 3 chloroperbenzoic acid allyl compound cellobiose disaccharide epoxide ethylene oxide derivative per o acetyl 1 thio beta dextro glucopyranose peracetic acid pyranoside silane derivative sugar sulfur derivative tert butyldimethylsilyl thiol unclassified drug acetylation article chemical bond chemical structure diastereoisomer epoxidation proton nuclear magnetic resonance reaction analysis ring opening synthesis Carbohydrate Conformation Carbohydrates Disaccharides Epoxy Compounds Stereoisomerism Manzano, V.E. Uhrig, M.L. Varela, O. Straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides |
| topic_facet |
Chemical reactions Derivatives Epoxidation Polysaccharides Silicones Sugar (sucrose) Sulfur Synthesis (chemical) Cellobiose Chemical equations D-glucopyranose Diastereo-selectivity Diastereoselective epoxidation Erythro Facial selectivity Laminarabiose M-chloroperbenzoic acid Oxirane Ring-opening Tert-butyldimethylsilyl Thiodisaccharide Sugars 2 propyl 3,4 dideoxy alpha dextro erythrohex 3 enopyranoside 2 propyl 6 o acetyl 3,4 anhydro alpha dextro allopyranoside 3 chloroperbenzoic acid allyl compound cellobiose disaccharide epoxide ethylene oxide derivative per o acetyl 1 thio beta dextro glucopyranose peracetic acid pyranoside silane derivative sugar sulfur derivative tert butyldimethylsilyl thiol unclassified drug acetylation article chemical bond chemical structure diastereoisomer epoxidation proton nuclear magnetic resonance reaction analysis ring opening synthesis Carbohydrate Conformation Carbohydrates Disaccharides Epoxy Compounds Stereoisomerism |
| description |
(Chemical Equation Presented) 3,4-Anhydro hexopyranosides have been prepared by diastereoselective epoxidation of derivatives of 2-propyl 3,4-dideoxy-α-D-erythro-hex-3-enopyranoside (5), selectively protected at HO-2 and HO-6. The allylic group at C-2, in 5 and derivatives, plays a critical role in the facial selectivity of the epoxidation reaction. Thus, the free HO-2 in 3 (the 6-O-acetyl derivative of 5) directs the attack of m-chloroperbenzoic acid from the more hindered α face of the molecule to give 2-propyl 6-O-acetyl-3,4-anhydro-α-D-allopyranoside (7) accompanied by the β epoxide 6 as a very minor product. Reverse diastereoselectivity has been obtained when the HO-2 in 3 was substituted by a bulky tert-butyldimethylsilyl (TBS) group. In this case, the major isomer was the 2-O-TBS derivative of 6 (α-D-galacto configuration). The ring-opening of sugar epoxides by nucleophilic per-O-acetyl-1-thio-β-D-glucopyranose (11) was employed as a convenient approach to the synthesis of (1→3)-and (1→4)- thiodisaccharides. For example, ring-opening of the oxirane 7 by 11 led to the expected regioisomeric per-O-acetyl thiodisaccharides β-D-Glc-S-(1→3)- 4-thio-α-D-Glc-O-iPr (12) and β-D-Glc-S-(1→4)4-thio-α-D- Gul-O-iPr (13). Regioselectivity in the construction of the (1→4)- thioglycosidic linkage could be achieved by hindering C-3 of the 3,4-anhydro sugar with a bulky silyloxy group at the vicinal C-2. For instance, coupling of the 2-O-TBS derivative of 7 with 11 led regioselectively to the protected thiodisaccharide β-D-Glc-S-(1→4)-4-thio-α-D-Glc-O-iPr (27). The utility of the approach was demonstrated through the synthesis of sulfur-linked analogues of naturally occurring (laminarabiose and cellobiose) and non-natural disaccharides (i.e., β-D-Glc-(1→4)-α-D-Gul). © 2008 American Chemical Society. |
| format |
JOUR |
| author |
Manzano, V.E. Uhrig, M.L. Varela, O. |
| author_facet |
Manzano, V.E. Uhrig, M.L. Varela, O. |
| author_sort |
Manzano, V.E. |
| title |
Straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides |
| title_short |
Straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides |
| title_full |
Straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides |
| title_fullStr |
Straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides |
| title_full_unstemmed |
Straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides |
| title_sort |
straightforward synthesis of thiodisaccharides by ring-opening of sugar epoxides |
| url |
http://hdl.handle.net/20.500.12110/paper_00223263_v73_n18_p7224_Manzano |
| work_keys_str_mv |
AT manzanove straightforwardsynthesisofthiodisaccharidesbyringopeningofsugarepoxides AT uhrigml straightforwardsynthesisofthiodisaccharidesbyringopeningofsugarepoxides AT varelao straightforwardsynthesisofthiodisaccharidesbyringopeningofsugarepoxides |
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