Unsaturated glycosyl

Scheme 4.55 Glycosylation with a 2,3-unsaturated glycosyl sulfone.

The Ferrier reaction of glycal derivatives has been extensively studied and recently reviewed <2001TCC153>. Additionally, the transformation of glycals into 2,3-unsaturated glycosyl derivatives has also been reviewed... 

Ultraviolet, infrared, and x-ray data on compound 45 have been reported,81 and it has been pointed out4 that, in this series, the anomeric pairs of glycosides that have so far been examined conform with Hudson s isorotation rules, unlike some 2,3-unsaturated glycosyl esters.51,91 Features of the nuclear magnetic resonance spectra are... 

A crystal structural analysis of mwco-inositol is referred to in Chapter 21. iV-(2-chloroethyl)-iV-nitrosoureido derivatives of cyclopentane- and cyclohexane-tetrols are mentioned in Chapter 18. Unsaturated glycosylated cyclitol derivatives are referred to in Chapter 12. 

The n.m.r. data for 6-deoxy-6-fluoro-ot- and - D-glucopyranose obtained at 300 MHz in DjO has been reported with a discussion of chemical shifts and coupling constant values. N.m.r. data on the unsaturated sugar derivatives (5) and (6), as well as on some fructofuranose derivatives useful as intermediates in a new synthesis of sucrose, have been published. The complete elucidation of the H n.m.r. spectra of the 2,3-unsaturated glycosyl phosphonates of type (7)... 

Several more complex trisaccharides involving modified sugars have been prepared for example 1, which is an aureolic acid-related compound made from a 2-phenylthioglycosyl trichloroacetimidate derived from the glycal 2 by solid phase technology, and the C-3 trisaccharide 3 of antibiotic PI-080, the unsaturated unit of which was coupled using the relevant unsaturated glycosyl tetrazole derivative. ... 

The subject of the present review is the displacement reaction of glycal derivatives like 1 that gives rise to 2,3-unsaturated glycosyl products, e. g. 2 (X = OR, SR, NR R, CR R R, Scheme 1). This reaction can also be used for synthetic purposes, the 0- and C-glycosides being of particular significance. The general features of the reactions exemplified by 1 2 will be discussed as well as specific examples, uses and modifications. A more extensive survey of this topic has been prepared [2]. 

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