Synthesis of a tetrasaccharide related to the triterpenoid saponin Bellisoside isolated from Bellis perennis (compositae)

A concise synthesis of a tetrasaccharide related to the triterpenoid saponins Bellisoside has been accomplished from commercially available monosaccharides through rational protecting group manipulations and stereoselective glycosylations. For the glycosylation reactions, H2SO4-silica has been successfully used as an alternative to conventional Lewis acids such as TfOH or TMSOTf. The target tetrasaccharide has been synthesized in the form of its p-methoxyphenyl glycoside which leaves scope for further glyco-conjugate formation through the selective deprotection of p-methoxyphenyl glycoside followed by trichloroacetimidate chemistry.