51
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Abstract
Regioselective glycosylation with allyl 4,6-O-benzylidene-alpha,beta-D-glucopyranoside or methyl 4,6-O-benzylidene-alpha,beta-D-glucopyranoside as the acceptor was investigated. It was found that the regioselectivity depends upon donor size and anomeric configuration of the acceptor, i.e., with a monosaccharide donor and an alpha-form acceptor, the (1-->3)-linked product was obtained predominantly or exclusively, while with disaccharide or trisaccharide donors and either an alpha or beta form acceptor, the (1-->2)-linked oligosaccharides were the only products.
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Affiliation(s)
- Ying Zeng
- Research Center for Eco-Environmental Sciences, Academia Sinica, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China
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52
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Wang H, Ning J. A one-pot strategy for synthesis of 5-O-(alpha-D-arabinofuranosyl)-6-O-(beta-D-galactofuranosyl)-D-galactofuranose present in motif E of the Mycobacterium tuberculosis cell wall. J Org Chem 2003; 68:2521-4. [PMID: 12636432 DOI: 10.1021/jo026325a] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
5-O-(Alpha-D-arabinofuranosyl)-6-O-(beta-D-galactofuranosyl)-D-galactofuranose 6 present in motif E of the Macobacterium tuberculosis cell wall has been regio- and stereospecifically synthesized using 3-O-benzoyl-1,2-O-isopropylidine-alpha-D-galactofuranose (10) as the glycosyl acceptor by the trichloroacetamidate method in a one-pot manner. The diol glycosyl acceptor 10 was smoothly derived from 1,2:5,6-di-O-isopropylidene-alpha-D-galactofuranose (8) by 3-O-benzoylation and then selective 5,6-O-deacetonation. The preparation of 8 was greatly improved by increasing the ratio of DMF to acetone and using a solid-supported catalyst.
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Affiliation(s)
- Hairong Wang
- Department of Chemistry, Tsinghua University, Beijing 100084, China
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53
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Vidal S, Montero JL, Leydet A, Morère A. A Flexible Route to Mannose 6-Phosphonate Functionalized Derivatives. PHOSPHORUS SULFUR 2002. [DOI: 10.1080/10426500214297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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54
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Mach M, Schlueter U, Mathew F, Fraser-Reid B, Hazen KC. Comparing n-pentenyl orthoesters and n-pentenyl glycosides as alternative glycosyl donors. Tetrahedron 2002. [DOI: 10.1016/s0040-4020(02)00671-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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55
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Jayaprakash K, Radhakrishnan K, Fraser-Reid B. Ytterbium(III) trifluoromethanesulfonate for specific activation of n-pentenyl orthoesters in the presence of acid-sensitive functionalities. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)01590-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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56
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Pure α-linked products can be obtained in high yields in glycosylation with glucosyl trichloroacetimidate donors with a C2 ester capable of neighboring group participation. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)00584-1] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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57
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Zhang J, Kong F. Synthesis of an xylosylated rhamnose pentasaccharide, the repeating unit of the O-chain polysaccharide of the lipopolysaccharide of Xanthomonas campestris pv. begoniae GSPB 525. Carbohydr Res 2002; 337:391-6. [PMID: 11861012 DOI: 10.1016/s0008-6215(01)00330-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A xylosylated rhamnose pentasaccharide, alpha-L-Rhap-(1-->3)-[beta-L-Xylp-(1-->2)-]-alpha-L-Rhap-(1-->3)-[beta-L-Xylp-(1-->4)]-L-Rhap, the repeating unit of the O-chain polysaccharide (OPS) of the lipopolysaccharides of Xanthomonas campestris pv. begoniae GSPB 525 was synthesized by a highly regio- and stereoselective way. Thus coupling of 1,2-O-ethylidene-beta-L-rhamnopyranose (1) with 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate (2) to give (1-->3)-linked disaccharide (3), subsequent benzoylation, deethylidenation, acetylation, 1-O-deacetylation, and trichloroacetimidation afforded the disaccharide donor 11. Condensation of 11 with 1 yielded 2,3,4-tri-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->3)-2-O-acetyl-4-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->3)-1,2-O-ethylidene-beta-L-rhamnopyranose (12), and selective deacetylation of 12 yielded the trisaccharide diol acceptor 15. Coupling of 15 with 2,3,4-tri-O-benzoyl-alpha-L-xylopyranosyl trichloroacetimidate (16), followed by deprotection, gave the target pentasaccharide 19.
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Affiliation(s)
- Jianjun Zhang
- Research Center for Eco-Environmental Sciences, Academia Sinica, PO Box 2871, 100085, Beijing, PR China
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58
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Zhu Y, Chen L, Kong F. A facile regio- and stereoselective synthesis of mannose octasaccharide of the N-glycan in human CD2 and mannose hexasaccharide antigenic factor 13b. Carbohydr Res 2002; 337:207-15. [PMID: 11844490 DOI: 10.1016/s0008-6215(01)00307-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A highly concise and effective synthesis of the mannose octasaccharide of the N-linked glycan in the adhesion domain of human CD2 was achieved via TMSOTf-promoted selective 6-glycosylation of a trisaccharide 4,6-diol acceptor with a pentasaccharide donor, followed by deprotection. The pentasaccharide was constructed by selective 3,6-diglycosylation of 1,2-O-ethylidene-beta-D-mannopyranose with 2-O-acetyl-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate, while the trisaccharide was obtained by selective 3-O-glycosylation of allyl 4,6-O-benzylidene-alpha-D-mannopyranoside with the same disaccharide trichloroacetimidate, followed by debenzylidenation. The mannose hexasaccharide antigenic factor 13b was synthesized by condensation of a trisaccharide donor, 2-O-acetyl-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->3)-4,6-di-O-acetyl-2-O-benzoyl-alpha-D-mannopyranosyl trichloroacetimidate, with a trisaccharide acceptor, methyl 3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->2)-3,4,6-tri-O-benzoyl-alpha-D-mannopyranoside, followed by deprotection.
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Affiliation(s)
- Yuliang Zhu
- Research Center for Eco-Environmental Sciences, Academia Sinica, PO Box 2871, 100085, Beijing, China
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59
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Zhu Y, Kong F. A FACILE SYNTHESIS OF MANNOSE TRI- AND TETRASACCHARIDE REPEATING UNITS OF FUNGAL CELL-WALL POLYSACCHARIDE FROMMICROSPORUMANDTRYCHOPHYTONSPECIES. SYNTHETIC COMMUN 2002. [DOI: 10.1081/scc-120003613] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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60
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Yamago S, Yamada T, Hara O, Ito H, Mino Y, Yoshida JI. A new, iterative strategy of oligosaccharide synthesis based on highly reactive beta-bromoglycosides derived from selenoglycosides. Org Lett 2001; 3:3867-70. [PMID: 11720556 DOI: 10.1021/ol016713j] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Stereoselective conversion of a selenoglycoside to a beta-bromoglycoside in the absence of a glycosyl acceptor followed by the coupling with another selenoglycoside affords the corresponding glycosylated selenoglycoside, which could be directly used for the next glycosylation. The iteration of this sequence allows the synthesis of a variety of oligosaccharides including an elicitor active heptasaccharide. [reaction: see text]
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Affiliation(s)
- S Yamago
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto 606-8501, Japan.
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61
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Zhang J, Zhu Y, Kong F. Synthesis of an L-rhamnose tetrasaccharide, the common and major structure of the repeating unit of the O-antigenic polysaccharide of a strain of Klebsiella pneumoniae and Pseudomonas holci. Carbohydr Res 2001; 336:229-35. [PMID: 11705472 DOI: 10.1016/s0008-6215(01)00258-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A tetrasaccharide, alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->2)-alpha-L-Rhap-(1-->2)-L-Rhap, the common and major structure of the repeating unit of the O-antigenic polysaccharide of a strain of Klebsiella pneumoniae and Pseudomonas holci was synthesized as its methyl and octyl glycosides. Selective 3-O-glycosylation of allyl alpha-L-rhamnopyranoside with 2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl trichloroacetimidate gave allyl 2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->3)-alpha-L-rhamnopyranoside (3). Benzoylation, deallylation, and trichloroacetimidation afforded 2,3,4-tri-O-acetyl-alpha-L-rhamnopyranosyl-(1-->3)-2,4-di-O-benzoyl-alpha-L-rhamnopyranosyl trichloroacetimidate (6). Self condensation of 3,4-di-O-benzoyl-beta-L-rhamnopyranose 1,2-methyl orthoester or 1,2-octyl orthoester gave methyl or octyl 2-O-acetyl-3,4-di-O-benzoyl-alpha-L-rhamnopyranosyl-(1-->2)-3,4-di-O-benzoyl-alpha-L-rhamnopyranoside (16 or 17), and subsequent selective deacetylation gave the disaccharide acceptor (18 or 19). Coupling of 6 with 18 (or 19), followed by deacylation in ammonia-saturated methanol, produced the target tetrasacharide.
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Affiliation(s)
- J Zhang
- Research Center for Eco-Environmental Sciences, Academia Sinica, PO Box 2871, Beijing 100085, PR China
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62
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Adinolfi M, Barone G, Iadonisi A, Mangoni L, Schiattarella M. Activation of disarmed 2-O-alkoxycarbonylated glycosyl trichloroacetimidates with lanthanide triflates: an efficient approach for the synthesis of 1,2-trans glycosides. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)01158-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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63
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Zhu Y, Kong F. A facile and effective synthesis of alpha-(1-->6)-linked mannose di-, tri-, tetra-, hexa-, octa-, and dodecasaccharides, and beta-(1-->6)-linked glucose di-, tri-, tetra-, hexa-, and octasaccharides using sugar trichloroacetimidates as the donors and unprotected or partially protected glycosides as the acceptors. Carbohydr Res 2001; 332:1-21. [PMID: 11403082 DOI: 10.1016/s0008-6215(01)00070-2] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Reaction of 2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl trichloroimidate with allyl alpha-D-mannopyranoside in the presence of TMSOTf selectively gave allyl 2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl-(1-->6)-alpha-D-mannopyranoside through an orthoester intermediate. Benzoylation of 3, followed by deallylation, and then trichloroimidation afforded the disaccharide donor 2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroimidate, while benzoylation of 3 followed by selective removal of acetyl groups yielded the disaccharide acceptor allyl alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranoside. Coupling of 5 with 6 gave the tetrasaccharide allyl 2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->6)-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranoside, which were converted into the tetrasaccharide donor 2,3,4,6-tetra-O-acetyl-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl trichloroimdate and the tetrasaccharide acceptor allyl alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranosyl-(1-->6)-2,3,4-tri-O-benzoyl-alpha-D-mannopyranoside, respectively, by the same strategies as used for conversion of 3 into 5 and 6. Condensation of 5 with 13 gave the hexasaccharide 14, while condensation of 12 with 13 gave the octasaccharide 17. Dodecasaccharide 21 was obtained by the coupling of 12 with the octasaccharide acceptor 20. Similar strategies were used for the syntheses of beta-(1-->6)-linked glucose di-, tri-, tetra-, hexa-, and octamers. Deprotection of the oligosaccharides in ammonia-saturated methanol yielded the free alpha-(1-->6)-linked mannosyl and beta-(1-->6)-linked glucosyl oligomers.
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Affiliation(s)
- Y Zhu
- Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Academia Sinica, Beijing, People's Republic of China
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64
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Yang Z, Lin W, Yu B. Rearrangement of sugar 1,2-orthoesters to glycosidic products: a mechanistic implication. Carbohydr Res 2000; 329:879-84. [PMID: 11125831 DOI: 10.1016/s0008-6215(00)00242-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The identification of cross-over products in the rearrangement of two structurally similar sugar 1,2-orthoesters to glycosidic products is reported.
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Affiliation(s)
- Z Yang
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, PR China
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65
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Du Y, Pan Q, Kong F. Synthesis of a tetrasaccharide representing a minimal epitope of an arabinogalactan. Carbohydr Res 2000; 323:28-35. [PMID: 10782282 DOI: 10.1016/s0008-6215(99)00252-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The hydrophobic alkyl chain-containing tetrasaccharide, dodecyl beta-D-galactopyranosyl-(1-->6)-beta-D-galactopyranosyl-(1-->6)-[alpha-L - arabinofuranosyl-(1-->2)]-beta-D-galactopyranoside, was synthesized efficiently using a convergent strategy. In coupling reactions, protected trichloroacetimidates proved to be better donors than their corresponding bromides in the preparation of the dodecyl disaccharide and trisaccharide. Zemplén deacylation provided the target tetramer in good overall yield.
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Affiliation(s)
- Y Du
- Research Center for Eco-Environmental Sciences, Academia Sinica, Beijing, China
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66
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Kaji E, Harita N. Stannylene acetal-mediated regioselective open glycosylation of methyl β-d-galactopyranoside and methyl α-l-rhamnopyranoside. Tetrahedron Lett 2000. [DOI: 10.1016/s0040-4039(99)01997-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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67
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Wang W, Kong F. Facile Syntheses of the Trisaccharide Acceptors—The Key Intermediates for Assembling the Elicitor Hexasaccharide. SYNTHETIC COMMUN 1999. [DOI: 10.1080/00397919908085942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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68
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Dios A, Nativi C, Capozzi G, Franck RW. Novel Stereoelectronic Behavior of Bicyclic Glycosyl Donors: Application to the Synthesis of Both 2-Deoxy-α- and -β-Glycosides. European J Org Chem 1999. [DOI: 10.1002/(sici)1099-0690(199908)1999:8<1869::aid-ejoc1869>3.0.co;2-a] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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69
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Wang W, Kong F. Highly Regio- and Stereoselective Synthesis of Bioactive Oligosaccharides Using 1,2-O-Ethylidene-α-d-gluco- and -β-d-Mannopyranose as the Acceptors and Acetobromosugars as the Donors via Ortho Ester Intermediates. J Org Chem 1999; 64:5091-5095. [DOI: 10.1021/jo982508e] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Wei Wang
- Research Center for Eco-Environmental Sciences, Academia Sinica, P.O. Box 2871, Beijing 100085, China
| | - Fanzuo Kong
- Research Center for Eco-Environmental Sciences, Academia Sinica, P.O. Box 2871, Beijing 100085, China
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70
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Wang W, Kong F. Hochregio- und hochstereoselektive Synthese von mannosehaltigen Oligosacchariden mit Acetylbromzuckern als Donoren und teilweise geschützten Mannosederivaten als Acceptoren über Zuckerorthoester-Zwischenstufen. Angew Chem Int Ed Engl 1999. [DOI: 10.1002/(sici)1521-3757(19990503)111:9<1330::aid-ange1330>3.0.co;2-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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71
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A highly stereocontrolled synthesis of 1β,1β-linked acetylated oligosaccharides via orthoester formation-rearrangement. Tetrahedron Lett 1999. [DOI: 10.1016/s0040-4039(98)02626-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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72
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73
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Wang W, Kong F. A highly convergent and effective synthesis of the phytoalexin elicitor hexasaccharide. Carbohydr Res 1999; 315:117-27. [PMID: 10385974 DOI: 10.1016/s0008-6215(99)00003-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The peracetylated hexasaccharide 1,2,4-tri-O-acetyl-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-6- O- (2,3,4-tri-O-acetyl-6-O-(2,4-di-O-acetyl-3,6-di-O-(2,3,4,6-tetra-O-acety l- beta-D-glucopyranosyl)-beta-D-glucopyranosyl)-beta-D-glucopyranosyl)-alp ha, beta-D-glucopyranose 21 was synthesized in a blockwise manner, employing trisaccharide trichloroacetimidate 2,4-di-O-acetyl-3,6-di-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)- alpha-D-glucopyranosyl trichloroacetimidate 17 as the glycosyl donor, and trisaccharide 4-O-acetyl-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-6-O-(2,3,4 -tri -O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S)ethylidene-alpha-D-glucopyra nose 18 as the acceptor. The donor 17 and acceptor 18 were readily prepared from trisaccharides 3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-6-O-(2,3,4-tri-O-acet yl- 6-O-chloroacetyl-beta-D-glucopyranosyl)-1,2-O-(R,S)ethylidene-alpha-D- glucopyranose 10 and 3,6-di-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S) ethylidene-alpha-D-glucopyranose 11, respectively, which were obtained from rearrangement of orthoesters 3,4-di-O-acetyl-6-O-chloroacetyl-alpha-D-glucopyranose 1,2-(3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S) ethylidene-alpha-D-glucopyranosid-6-yl orthoacetate) 8 and 3,4,6-tri-O-acetyl-alpha-D-glucopyranose 1,2-(3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S) ethylidene-alpha-D-glucopyranosid-6-yl orthoacetate) 9, respectively. The orthoesters were prepared from selective coupling of the disaccharide 3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S) ethylidene-alpha-D-glucopyranose 4 with 'acetobromoglucose' (tetra-O-acetyl-alpha-D-glucopyranosyl bromide) and 6-O-chloroacetylated 'acetobromoglucose', respectively. To confirm the selectivity of the orthoester formation and rearrangement, the disaccharide 4-O-acetyl-3-O-(2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl)-1,2-O-(R,S ) ethylidene-alpha-D-glucopyranose 7 was prepared from 4 by selective tritylation, acetylation and detritylation. The title compound, an elicitor-active D-glucohexaose 3-O-(beta-D-glucopyranosyl)-6-O-(6-O-(3,6-di-O-(beta-D-glucopyranosyl)-b eta -D-glucopyranosyl)-beta-D-glucopyranosyl)-alpha,beta-D-glucopyranose 1, was finally obtained by Zemplén deacetylation of 21 in quantitative yield.
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Affiliation(s)
- W Wang
- Research Center for Eco-Environmental Sciences, Academia Sinica, Beijing, People's Republic of China
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74
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Du Y, Kong F. The Regio- and Stereoselective Synthesis of Rhamnose-Containing OligosaccharidesViaSugar-Sugar Orthoester Formation and Rearrangement. J Carbohydr Chem 1999. [DOI: 10.1080/07328309908544027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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75
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Wang W, Kong F. Regio-and Stereoselective Synthesis of Oligosaccharides with Acetobromolactose and Acetobromomaltose as Glycosyl Donors Via Orthoester Intermediates. J Carbohydr Chem 1999. [DOI: 10.1080/07328309908544009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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