Preferred Conformations of C-Glycosides. 14. Synthesis and Conformational Analysis of Carbon Analogs of the Blood Group Determinant H-Type II
作者:Alexander Wei、Arnaud Haudrechy、Catharine Audin、Hyuk-Sang Jun、Nathalie Haudrechy-Bretel、Yoshito Kishi
DOI:10.1021/jo00112a040
日期:1995.4
The syntheses of C-trisaccharides 1-4, carbon analogs of the human blood group determinant II-type II, have been achieved in a flexible and efficient manner. Vicinal coupling constants in the H-1 NMR spectrum provide experimental evidence that each of the four compounds 1-4 possesses a unique solution conformation, in accord with the predictions made on the basis of the preference of the C-glycosidic bond for the ''exo-anomeric'' conformation and the influence of 1,3-diaxial like interactions about the C-aglyconic bond.