Use of glycosyl fluorides

In the Koenigs-Knorr method and in the Helferich or Zemplen modifications thereof, a glycosyl halide (bromide or chloride iodides can be produced in situ by the addition of tetraalkylammonium iodide) is allowed to react with a hydrox-ylic compound in the presence of a heavy-metal promoter such as silver oxide, carbonate, perchlorate, or mercuric bromide and/or oxide,19-21 or by silver triflu-oromethanesulfonate22 (AgOTf). Related to this is the use of glycosyl fluoride donors,23 which normally are prepared from thioglycosides.24... 

SCHEME 4.11 Use of glycosyl fluorides obtained by 1,2-seleno migration. 

Cumpstey, I, Fairbanks, A J, Redgrave, A J, Stereospecific synthesis of 1,2-cis glycosides by allyl-mediated intramolecular aglycon delivery. 2. The use of glycosyl fluorides, Org. Lett, 3,2371-2374, 2001. 

Araki, Y, Kobayashi, N, Watanabe, K, Ishido, Y, Synthetic studies by the use of fluorinated intermediates. Part 2. Synthesis of glycosyl cyanides and C-allyl glycosides by the use of glycosyl fluoride derivatives, J. Carbohydr. Chem., 4, 565-585, 1985. 

Pyranold Compounds.- The use of glycosyl fluorides in the synthesis of C-glycosides has been covered in a review on fluorinated carbohydrates, and the work of Sinay s group on C -glycoslde synthesis from 1-llthlo derivatives and from glycosyl phenylsulphones has appeared in the form of a published lecture. 

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