Construction of β-Mannosidic Bonds via Gold(I)-Catalyzed Glycosylations with Mannopyranosyl <i>ortho</i>-Hexynylbenzoates and Its Application in Synthesis of Acremomannolipin A

Abstract

A mild and convenient protocol for direct synthesis of β-mannosides has been developed. Glycosylation of 4,6-O-benzylidene-protected mannosyl ortho-hexynylbenzoates with various alcohol acceptors catalyzed by gold(I) complex proceeded smoothly at 0 °C to room temperature and afforded the corresponding β-mannoside in high yield and satisfactory stereoselectivity. This reaction was applied to the total synthesis of acremomannolipin A and its analogue.