Glucose series

Methods of Formation.—The only 2,5-dimethyl derivatives in the glucose series of which the authors have any record are those of D-glu-curonic acid and of 3,6-anhydro-D-glucose. D-Glucuronolactone with cold acidic methanol gives the y-lactone of methyl /3-D-glucofururonoside, which can be converted by treatment with methyl iodide and silver oxide into the sirupy y-lactone of methyl 2,5-dimethyl-/ -D-glucofururonos-... 

B. Bernet and A. Vasella, Carbocyclic compounds from carbohydrates. 1. Transformations in the glucose series, Helv. Chim. Acta, 62 (1979) 1990-2016. 

For a detailed study of this reaction, see Danishefsky, S J, Deninno, M P, Philips, G B, Zelle, R E, Lartey, P A, On the communication of chirality from furanose and pyranose rings to monosaccharide side chains anomalous results in the glucose series. Tetrahedron, 42, 2809-2819, 1986. 

Position Glucose series Galactose series Other series... 

As would be anticipated for a phenomenon which is fundamentally electrostatic, this effect is attenuated in polar solvents a-glucosylimidazole in water does not change conformation on protonation [17]. There is evidence that the anomeric effect itself is likewise solvent sensitive. Table 1 gives representative data on the strength of the anomeric effect (defined as the additional stabihsation of the axial substituent in the glucose series, compared with cyclohexane). 

Equilibration studies of systems in nitromethane and in acetonitrile have been conducted with the acetoxonium-salt mixture obtained from 69. As indicated in Table III, in nitromethane, the a- and jS-D-arabino ions (74 and 75) are favored to the extent of 57%. The equilibrium composition corresponds approximately to the composition of the salt isolated from 69 at 25°. In acetonitrile, in contrast, the D xylo ion (72) is favored to the extent of 55%. The content (10-12%) of the D-lyxo ion (73) in the solution thus resembles that of the D-manno ion (60) in the corresponding rearrangement in the D-glucose series. 

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