四种齐墩果酸皂苷的合成

Synthesis of Four Oleanolic Saponins

为获得高活性齐墩果酸皂苷药物候选分子,报道了4种单糖(葡萄糖、半乳糖、木糖、阿拉伯糖)与齐墩果酸的C3羟基进行糖苷化反应合成皂苷的方法。在合成中采用糖的全苯甲酰化三氯乙酰亚胺酯为糖基供体,齐墩果酸烯丙醇酯为糖基受体,在三氟甲磺酸三甲基硅醇酯(TMSOTf)的作用下,糖基供体与齐墩果酸的C3羟基进行糖苷化,以较高的收率和专一的立体选择性得到4种齐墩果酸单糖皂苷。化合物结构经核磁共振波谱得以确证。

Four triterpene saponins, Oleanolic acid 3-yl (β-D-glucopyranoside, β-D-galactopyranoside, β-D-xylopyranoside and α-L-arabinopyranoside) were synthesized using trichloroacetimidates as donors and TMSOTf as a promoter. The glycosylation of allyl oleanate with sugar moieties was stereospecific and high yielding. The structures of title compounds were identified by NMR spectra.