Acta Cryst. (2002). E58, o224-o226  [ doi:10.1107/S1600536802001952 ]

Methyl (2'R,3'R)-6-deoxy-3,4-O-(2',3'-dimethoxybutane-2',3'-diyl)-2-O-toluene-p-sulfonyl--L-mannopyranoside

J. C. Barnes, J. S. Brimacombe, L. M. C. Connolly and A. P. Dix

Abstract: In the title compound, C₂₀H₃₀O₉S, (III), both six-membered rings adopt chair conformations, placing H3 and the 2-sulfonyloxy group in the antiperiplanar arrangement required for an E2 reaction. However, unlike other -mannopyranoside-2-sulfonates, the 2-O-trifluoromethylsulfonyl (trifluoromethanesulfonate) derivative, (II), underwent an S_N2 displacement with an azide ion to give methyl (2'R,3'R)-2-azido-2,6-dideoxy-3,4-O-(2',3'-dimethoxybutane-2',3'-diyl)--L-glucopyranoside, (IV), in preference to the E2 reaction.

Online 8 February 2002

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