Comparative investigations on the regioselective mannosylation of 2,3,4-triols of mannose

Regioselective glycosylation of 2,3,4-unprotected benzyl α-d-mannopyranoside and allyl α- and -β-d-mannopyranosides has been investigated. The configuration at the anomeric centre influences the outcome of the reaction. Possible role of hydrogen-bonding network in glycosylation of the above triols used as glycosidic acceptors is discussed.

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Allyl 6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC25H34O6Si[α]D20=<1 (c 0.6, CHCl3)Source of chirality: d-(+)-mannose

(2′S,3′S)-Allyl 3,4-O-(2′,3′-dimethoxybutane-2′,3′-diyl)-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC31H44O8Si[α]D20=+118.0 (c 0.5, CHCl3)Absolute configuration: (2′S,3′S)Source of chirality: d-(+)-mannose

Allyl 6-O-tert-butyldiphenylsilyl-2,3-O-isopropylidene-α-d-mannopyranosideC28H38O6Si[α]D20=+2.6 (c 0.4, CHCl3)Source of chirality: d-(+)-mannose

Allyl 6-O-tert-butyldiphenylsilyl-β-d-mannopyranosideC25H34O6Si[α]D20=-49.5 (c 0.6, CHCl3)Source of chirality: d-(+)-mannose

Allyl 3,4-di-O-acetyl-6-O-tert-butyldiphenylsilyl-2-O-chloroacetyl-β-d-mannopyranosideC31H39ClO9Si[α]D20=-18.8 (c 0.43 CHCl3)Source of chirality: d-(+)-mannose

Allyl 3,4-di-O-acetyl-6-O-tert-butyldiphenylsilyl-β-d-mannopyranosideC29H38O8Si[α]D20=-20.6 (c 0.5, CHCl3)Source of chirality: d-(+)-mannose

Allyl 6-O-tert-butyldiphenylsilyl-2,3-O-isopropylidene-β-d-mannopyranosideC28H38O6Si[α]D20=-54.1 (c 0.3, CHCl3)Source of chirality: d-(+)-mannose

(2′S,3′S)-Benzyl 3,4-O-(2′,3′-dimethoxybutane-2′,3′-diyl)-α-d-mannopyranosideC19H28O8[α]D20=+202.8 (c 0.5, CHCl3)Source of chirality: d-(+)-mannose

(2′S,3′S)-Benzyl 3,4-O-(2′,3′-dimethoxybutane-2′,3′-diyl)-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC35H46O8Si[α]D20=+124.7 (c 0.7, CHCl3)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-6-O-tert-butyldiphenylsilyl-3,4-O-(2′,3′-dimethoxybutane-2′,3′-diyl)-α-d-mannopyranosideC65H70O17Si[α]D20=+7.0 (c 0.4, CHCl3)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC59H60O15Si[α]D20=-19.6 (c 0.3, CHCl3)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-3,4-di-O-acetyl-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC63H64O17Si[α]D20=-23.2 (c 0.5, chloroform)Source of chirality: d-(+)-mannose

Allyl2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-3,4-di-O-acetyl-6-O-tert-butyldiphenylsilyl-β-d-mannopyranosideC63H64O17Si[α]D20=-37.0 (c 0.5, CHCl3)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-β-d-mannopyranosideC43H42O15[α]D20=-46.3 (c 0.3, CHCl3)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-6-O-tert-butyldiphenylsilyl-β-d-mannopyranosideC59H60O15Si[α]D20=-30.7 (c 0.3, CHCl3)Source of chirality: d-(+)-mannose

Benzyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-6-O-tert-butyldiphenylsilyl-3,4-O-(2′,3′-dimethoxybutane-2′,3′-diyl)-α-d-mannopyranosideC69H72O17Si[α]D20=+14.7 (c 0.4, CHCl3)Source of chirality: d-(+)-mannose

Benzyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC63H62O15Si[α]D20=-9.4 (c 0.3, CHCl3)Source of chirality: d-(+)-mannose

Benzyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→2)-3,4-di-O-acetyl-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC67H66O17Si[α]D20=-5.2 (c 0.4, chloroform)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→3)-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC59H60O15Si[α]D20=-17.7 (c 0.6, CHCl3)Source of chirality:d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→3)-2,4-di-O-acetyl-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC63H64O17Si[α]D20=-7.4 (c 2.85, CHCl3)Source of chirality:d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→3)-6-O-tert-butyldiphenylsilyl-β-d-mannopyranosideC59H60O15Si[α]D20=-31.0 (c 0.6, CHCl3)Source of chirality:d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→3)-2,4-di-O-acetyl-6-O-tert-butyldiphenylsilyl-β-d-mannopyranosideC63H64O17Si[α]D20=-31.9 (c 1.8, CHCl3)Source of chirality:d-(+)-mannose

Benzyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→3)-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC63H62O15Si[α]D20=-10.4 (c 0.6, CHCl3)Source of chirality:d-(+)-mannose

Benzyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→3)-2,4-di-O-acetyl-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC67H66O17Si[α]D20=-3.0 (c 0.6, CHCl3)Source of chirality:d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→4)-6-O-tert-butyldiphenylsilyl-2,3-O-isopropylidene-α-d-mannopyranosideC62H64O15Si[α]D20=-3.5 (c 0.25, CHCl3)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→4)-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC59H60O15Si[α]D20=+10.9 (c 0.3, CHCl3)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→4)-2,3-di-O-acetyl-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC63H64O17Si[α]D20=+8.0 (c 0.4, chloroform)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→4)-6-O-tert-butyldiphenylsilyl-2,3-O-isopropylidene-β-d-mannopyranosideC62H64O15Si[α]D20=-30.3 (c 0.4, CHCl3)Source of chirality: d-(+)-mannose

Allyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→4)-6-O-tert-butyldiphenylsilyl-β-d-mannopyranosideC59H60O15Si[α]D20=-29.7 (c 0.35, CHCl3)Source of chirality: d-(+)-mannose

Benzyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→4)-6-O-tert-butyldiphenylsilyl-2,3-O-isopropylidene-α-d-mannopyranosideC66H66O15Si[α]D20=+11.6 (c 0.3, CHCl3)Source of chirality:d-(+)-mannose

Benzyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→4)-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC63H62O15Si[α]D20=+19.7 (c 0.3, CHCl3)Source of chirality: d-(+)-mannose

Benzyl 2,3,4,6-tetra-O-benzoyl-α-d-mannopyranosyl-(1→4)-2,3-di-O-acetyl-6-O-tert-butyldiphenylsilyl-α-d-mannopyranosideC67H66O17Si[α]D20=+16.7 (c 0.4, chloroform)Source of chirality: d-(+)-mannose