2-(Trimethylsilyl)ethyl Glycosides. Transformation into Glycopyranosyl Chlorides

Article abstract of DOI:10.1021/jo00297a038

2-(Trimethylsilyl)ethyl (TMSET) glycosides were transformed in high yields into the corresponding 1-chloro sugars by treatment with 1,1-dichloromethyl methyl ether/zinc chloride.With acetyl, benzoyl, and benzyl protection of the 2-postion, the α-glycopyranosyl chloride was the major product, whereas with the 2-phthalimido sugar 13, the β-chloride 21 was obtained.The fully benzylated TMSET glucopyranoside 1 gave the α-chloro sugar 22 carrying a 6-O-formyl group whereas the partially benzylated sugars 16 and 17 gave the chloro sugars with all protecting groups intact.