Access to Diosgenyl Glycoconjugates via Gold(I)-Catalyzed Etherification of Diosgen-3-yl ortho-Hexynylbenzoate
Li Zhang1, Linfeng Li2, Shujin Bai1
1Key Laboratory of Marine Medicine, Chinese Ministry of Education, School of Medicine and Pharmacy, Ocean University of China , Qingdao, Shandong 266003, P. R. China.
Abstract:
An efficient protocol for the synthesis of diverse diosgen-3-yl glycoconjugates, a class of novel synthetic analogs of natural saponins of biological significance, has been developed. The method relies on gold(I)-catalyzed etherification of diosgen-3-yl ortho-hexynylbenzoate with stoichiometric sugar alcohols to afford the corresponding glycoconjugates in 38%-99% yields. The reaction involves the preferential attack of hydroxyl groups to the C3 position of homoallylic carbocation intermediate and displays a broad substrate scope and a good functional group tolerance.
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