关键词: 齐墩果酸, 三萜, 糖苷, 红外分光光度法, 质子磁共振谱法, 碳十三核磁共振谱法

Four glycoconjugates (D-glucose, D-galactose, D -lactose and D - glucuronic acid) of oleanolic acid were synthesized through a facile approach. Firstly, D -glucose, D -galactose and D-lactose were converted into benzoyl group protected glycosyl trichloroacetimidates (lOa ~ lOc) as donors. D-glucuronic acid was converted into methyl (tri- 0-acetyl-a-.D-glucopyranosyl bromide)-uronate (lOd) as donor. Secondly, oleanolic acid was converted into methyl A~r-(3-hydroxylolean-12-en-28- oyl)-6-aminohexanoate (6). Then the coupling of the sugar moieties (10a~ lOc) to 3-OH of 6 was promoted by trimethylsilyl trifluoromethanesulfonate (TMSOTf) . AgOTf was used as the promoter in the glycosylation of lOd with 6. Finally, deprotection of the corresponding glycocongjugates afforded the target products 13a ~ 13d. The structures of all products were characterized by IR,~1H NMR, ~13C NMR, DEPT, tow-dimensional shift-correlated spectra (COSY, HMQC) and HRMS.

Key words: oleanolic acid, TRITERPENE, GLYCOSIDE, IR, 1HNMR, C13NMR