title: Efficient synthesis of a sialic acid alpha(2-->3)galactose building block and its application to the synthesis of ganglioside GM3.
abstract: Glycosylation of various galactose derivatives with O-acetylated sialic acid N-phenyltrifluoroacetimidate as the donor was investigated. Efficient alpha(2,3)sialylation of galactose, with up to 73% yield and 8.4:1 stereoselectivity, was realized when 2,3,4-unprotected galactose derivatives and TBSOTf were used as acceptors and promoter, respectively. Sialylation of 2-(trimethylsilyl)ethyl 6-O-tert-butyldiphenylsilyl-beta-D-galactopyranoside (3f) gave the best result, and the resultant Neu5Ac alpha(2-->3)Gal disaccharide was successfully used in the synthesis of ganglioside GM3.
authors.affiliation: Key Laboratory of Marine Drugs, The Ministration of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
authors.forename: Yunpeng
authors.initials: Y
authors.lastname: Liu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Ruan
authors.forename: Xiangpeng
authors.initials: X
authors.lastname: Li
authors.forename: Yingxia
authors.initials: Y
authors.lastname: Li
mesh_terms: D005679:G(M3) Ganglioside / Q000138:chemical synthesis*; D005690:Galactose / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D019158:N-Acetylneuraminic Acid / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D005679:G(M3) Ganglioside; D019158:N-Acetylneuraminic Acid; D005690:Galactose