Efficient synthesis of a sialic acid alpha(2-->3)galactose building block and its application to the synthesis of ganglioside GM3.
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.
Liu
Yunpeng
Y
Key Laboratory of Marine Drugs, The Ministration of Education of China, School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
Ruan
Xiaohong
X
Li
Xiangpeng
X
Li
Yingxia
Y
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
D005679:G(M3) Ganglioside; D019158:N-Acetylneuraminic Acid; D005690:Galactose