Glucopyranose derivative

Similarly, various a-D-glucopyranose derivatives having a mesyloxy group at C-4 and an acetoxyl group at C-l are also converted into 1,4-anhydro-/3-D-galactopyranose derivatives on treatment with sodium azide in such aprotic solvents as N,N-dimethylformamide.51 The use of sodium azide in N,N-dimethylformam ide under forcing conditions originated in attempts at nucleophilic displacements to form azido,... 

An approach to 2-deoxy-2-(thiocyanato)-D-glucopyranose derivatives has been reported by Igarashi and Honma.37 This reaction proceeds in the presence of acetic acid and acetic anhydride by addition of thiocyanogen to 3,4,6-tri-O-acetyl-D-glucal (20), with the formation of a mixture of isomeric thiocyanates (274 and 275) and isothiocyanate 21 (3% yield), as well as 3,4,6-tri-0-acetyl-2-(thiocyanato)-D-glucal (276). 

D. Tailler, J. C. Jacquinet, A. M. Noirot, and J. M. Beau, An expeditious and stereocontrolled preparation of 2-azido-2-deoxy-P-D-glucopyranose derivatives from D-glucal, J. Chem. Soc. Perkin Trans. /(1992) 3163-3164. 

H. Kamitakahara, F. Nakatsubo, and K. Murakami, Syntheses of 1,4-anhydro-u-D-glucopyranose derivatives having acyl groups, Mokuzai Gakkaishi, 40 (1994) 302-307. 

T. Yoshida, K. Hattori, Y. S. Choi, M. Arai, H. Funaoka, and T. Uryu, Synthesis and ring-opening polymerization of new 1,4-anhydro-glucopyranose derivatives, J. Polym. Sci., Part A Polym. Chem., 36 (1998) 841-850. 

H. Kamitakahara and F. Nakatsubo, Substituent effect on ring-opening polymerization of regioselectively acylated 1,4-anhydro-a-D-glucopyranose derivatives, Macromolecules, 29 (1996) 1119-1122. 

In wKich a-D-glucopyranose derivatives are sweeter or produce larger taste responses than B-D-glucopyranose derivatives. (2) The requirement of equatorial hydroxyls at C-2 and C-4 of the D-glucopyranoside molecule for a maximum stimulation in the gerbil parallels a similar requirement for increased sweet taste in man (33.) and maximum stimulation in the sugar receptors of the gly (31). (3) The residues at the... 

Acarbose is a glucopyranose derivative that acts by inhibiting intestinal a-gluco-sidase. This delays carbohydrate absorption and reduces the postprandial (1.5 hours after food) blood glucose levels and is used in combination with other sulfonyl-ureas. Acarbose may cause GI disturbances, flatulence, abdominal distortion, diarrhea, and pain. Acarbose should be avoided during pregnancy, as it affects the fetus. Acarbose is contraindicated in inflammatory bowel disease and hepatic dysfunction. 

FIGURE 2.36 The a,p-anomeric ratio of some D-glucopyranose derivatives. 

Matsubara, K, Sasaki, T, Mukaiyama, T, Catalytic stereoselective synthesis of a- or p-glucosides using a single glycosyl donor, l-0-2 -(2 -methoxyethoxy)acetyl-glucopyranose derivative, Chem. Lett, 1373-1376, 1993. 

Eby, R, Schuerch, C, The use of 1-O-tosyl-D-glucopyranose derivatives in a-D-glucoside s)mthesis,... 

As expected on the basis of the epoxy halide results just discussed, die displacement of a primary tosyl-ate can be smoothly accomplished in the presence of an adjacent disubstituted epoxide,and this reaction has been utilized in syntheses of disparlure and of other insect pheromones. On the other hand, a recently reported reaction of a cyclic glucopyranose-derived epoxide with either Me2CuLi or MeMgCl-CuBr afforded in high yield the desired ring-opened product, leaving intact an exocyclic primary mesylate. 

Selected reactions with C-l j -toluenesulfonates can be seen in Tables III and IV. In the series of 2,3,4-tri-Oj-benzyl-l-Q-g-tolylsulfonyl-D-glucopyranose derivatives, a few examples of the influence of C-6 substituent, solvent, and structure of reacting alcohol can be seen (Table III, no. 1-5). The S.-pheny 1 carbamate derivative (no. 5) has been used in a stepwise hexasaccharide synthesis (30), and has been used to prepare -aminophenylethyl glucotetraopyranosides for coupling to proteins (31). The stereoselectivity was equally good in the higher members of the series. 

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