The crystal structure of the title compound, C(30)H(38)N(2)O(5)Si, has been investigated to establish the relative stereochemistry at the spiro ring junction and the two anomeric centres. Each of the O atoms in the tetra-hydro-pyran rings adopts an axial position on the neighbouring ring. This bis--diaxial conformation is adopted, thus gaining maximum stablization from the anomeric effect. The ...

Glycosylation is an immensely important biological process and one that is highly controlled and very efficient in nature. However, in a chemical laboratory the process is much more challenging and usually requires the extensive use of protecting groups to squelch reactivity at undesired reactive moieties. Nonetheless, by taking advantage of the differential reactivity of the anomeric center, a...

Carbohydrates are an extremely complex group of isomeric molecules that have been difficult to analyze in the gas phase by mass spectrometry because (1) precursor ions and product ions to successive stages of MS(n) are frequently mixtures of isomers, and (2) detailed information about the anomeric configuration and location of specific stereochemical variants of monosaccharides within larger mo...

Partially protected monosaccharides with free anomeric hydroxyl groups are useful in the synthesis of oligosaccharides [ l-31. A number of chemical methods are reported to remove the anomeric acyl group of peracylated carbohydrates [ 4-61, providing a useful route to partially protected saccharides [ 7,8]. Enzymatic reactions have also been used for this purpose [ 9-231. According to previous r...

The possible involvement of mutarotases in glucose metabolism has been studied by examining the anomeric specificities of a number of glycolytic enzymes. Hexokinases from yeast or Ehrlich ascites tumor cells showed only a marginal preference for the cx anomer of glucose. (All configurations, unless otherwise specified, refer to the D configuration of glucose and its derivatives.) The K, values ...