Glycals preparation

I. Hanna, J. Pan, and J. Y. Lallemand, Optically active cyclobutanones from glycals Preparation and regioselective cleavage, Synlett p. 510 (1991). 

A more detailed paper on the kinetic resolution of nthetic racemic glycals containing an unprotected C-3 hydroxyl group, uang vinyl acetate and lipase PS-30 has appeared (See Vol. 25, p. 152, Scheme 3 for previous report). Glycals prepared by this method which have shown inhibition of the bovine a-L-fucosidase have been used to help map the active site of this enzyme. ... 

Methyl glycosides of 2 deoxy sugars have been prepared by the acid catalyzed addition of methanol to unsaturated sugars known as glycals... 

Easily prepared from the appropriate monosaccharide, a glycal is an unsatu-rated sugar with a C1-C2 double bond. To ready it for use in potysaccharide synthesis, the primary -OH group of the glycal is first protected at its primary -OH group by formation of a silvl ether (Section 17.8) and at its two adjacent secondary - OH groups by formation of a cyclic carbonate ester. Then, the protected glycal is epoxidized. 

Deoxy-sugars. Part XVII. An Investigation of the Glycal Method for the Preparation of Derivatives of 2-Deoxy-D-galactose, W. G. Overend, F. Shafizadeh, and M. Stacey, /. Chem. Soc., (1951) 992-993. 

Because of the high C - F bond energy, glycosyl fluorides are stable in comparison to the other glycosyl halides, and this character has attracted much attention. They have been prepared in many different ways. One of them, rather classical, is through addition of the elements of HF (for example, HF in benzene ), BrF, or IF to per-O-acylated glycals. ... 

E. Wieczorek and J. Thiem, Preparation of modified glycosyl glycerol derivatives by glycal rearrangement, Carbohydr. Res., 307 (1998) 263-270. 

Typical Procedure for the Preparation of Selenoglycosides from Glycals... 

Comprehensive reviews of the chemistry of both the glycals [105-107] and anhydro sugars [108,109] have appeared in the recent literature. This chapter will attempt to summarize what is known about their preparation and reactivity in the formation of the glycosidic linkage and highlight recent examples to emphasize practical and strategic considerations in the choice of glycosyl donors. 

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