2.6- Dideoxy glycosyl fluorides

Glycosylation. The reaction of and 2,6-dideoxy glycosyl fluorides with require an additional promoter. 

Glycosylation. The reaction of protected 2-deoxyglycosyl trichloroacetimidates and 2,6-dideoxy glycosyl fluorides with glycosyl acceptors in 0.1 M LiClO /EtjO does not require an additional promoter. 

C-Glycosyl derivatives may be prepared by utilizing glycosyl fluorides. Ishido and coworkers reported that the reaction of 2,3,5-tri-O-benzyl-a-(36a) or - -D-ribofuranosyl fluoride (36fi) with isopropenyl trimethylsilyl ether under BF3 catalysis (0.1 -0.05 mol. equiv. for the fluoride, in ether or acetonitrile) gave a mixture of 4,7-anhydro-5,6,8-tri-C)-benzyl-l,3-dideoxy-D-altro- (139, major) and -D-a//o-2-octulose (140) 139 was stated to isomerized to 140 (should be vice versa) under Lewis acid catalysis. Similar... 

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