Glucose derivatives

FeCl3, AC2O, 55-75% yield.The relative rates of cleavage for the 6-, 3-, and 2-O-benzyl groups of a glucose derivative are 125 24 1. Sulfuric acid has also been used as a catalyst. ... 

Bu3SnOMe, CICH2CH2CI, 1 h, 77% yield.These conditions selectively cleave the anomeric acetate of a glucose derivative in the presence of other acetates. 

For secondary derivatives, the selectivity and reactivity vary somewhat. To what extent this depends on the highly functionalized glucose derivative has not been determined. The table that follows gives the cleavage selectivity for the reaction... 

The inverse electron-demand catalytic enantioselective cycloaddition reaction has not been investigated to any great extent. Tietze et al. published the first example of this class of reaction in 1992 - an intramolecular cycloaddition of heterodiene 42 catalyzed by a diacetone glucose derived-titanium(IV) Lewis acid 44 to give the cis product 43 in good yield and up to 88% ee (Scheme 4.31) [46]. 

Danishefsky s diene 154 DBFOX 232 dendrimers 229 DPT calculations 308 diacetone glucose derived-titanium(IV) 178 diastereoselectivity 216 diazo compounds 242 diazoalkane cycloadditions 278 diazoalkanes 213, 231 (R,R)-4,6-dibenzofurandiyl-2,2 -bis(4-phenylox-azoline) 250... 

Glykosid. n. glycoside, glucoside. (Preferably, glycoside is the general term, glucoside denotes a glucose derivative.)... 

Metal halide salts other than sodium iodide have been used sparsely to prepare halodeoxy sugars from sulfonate esters. Lithium chloride (107) and lithium bromide (33) have found limited application. Potassium fluoride (dihydrate) in absolute methanol has been used (51, 52) to introduce fluorine atoms in terminal positions of various D-glucose derivatives. The reaction is conducted in sealed tube systems and requires... 

The formation of 120 can be explained by attack of chloride ion at C-6 (rather than the more hindred endo side at C-3) as depicted in the intermediate 126, with concomitant migration of the ketal function to the 3,5-position. This procedure provides a convenient route to 6-substituted D-glucose derivatives from the readily accessible 49. Since rotation about the C-5—0 bond is required for the migration of the ketal, the reaction most likely is not of a concerted nature and may proceed via 126a-126b. 

The widespread occurrence of long-range couplings in both furanose and pyranose derivatives explains why so many of the P.M.R. spectra of carbohydrate derivatives are apparently poorly resolved, even when the resolution of the spectrometer is above reproach. For example, the Hi resonance of the 1,6-anhydro-D-glucose derivative (12) is coupled to all of the other six ring protons. A further example of the line-broadening effect follows a consideration of the spectrum of 5,6-dideoxy-5,6-epithio-l,2-0-isopropylidene-/ -L-idofuranose for which the half-height... 

In another approach, a glucose-derived titanium enolate is used in order to accomplish stereoselective aldol additions. Again the chiral information lies in the metallic portion of the enolate. Thus, the lithiated /m-butyl acetate is transmetalated with chloro(cyclopentadienyl)bis(l,2 5,6-di-0-isopropylidene- -D-glucofuranos-3-0-yl)titanium (see Section I.3.4.2.2.I. and 1.3.4.2.2.2.). The titanium enolate 5 is reacted in situ with aldehydes to provide, after hydrolysis, /i-hydroxy-carboxylic acids with 90 95% ee and the chiral auxiliary reagent can be recovered76. 

R = 1-BuMe2Si, = a, then D-glucose derivative,b)— = p,then D-galactose derivative... 

Glucose derived from muscle glycogen and metabolized by anaerobic glycolysis is the major fuel source. Blood glucose and free fatty acids are the major fuel sources. 

Ganske and co-workers reported that lipase-catalyzed acylation of a glucose derivative proceeded smoothiy in a mixed soivent of [bmim][BF4] with r-BuOH, while no reaction took place in [bmim][BF4] (Fig. 12). These results taught us that a mixed soivent system of IL with organic solvent may be a good solution if the desired reaction did not take piace in a pure IL solvent. 

Kamp, F. P. van de, u. F. Micheel Uber D-Glucose-Derivative von Thio-semicarbazonen und ihre biologische Wirksamkeit. Chem. Ber. 89, 133 (1956). 

What is described as a domino Knoevenagel-hetero-Diels-Alder reaction , involving the reaction of the glucose-derived aldehyde 93 with a 1,3-dicarbonyl compound in presence of either proline or ethylenediammonium acetate, leads to the doubly annulated 5 6 6-fused compound 94 (Scheme 30) <2004S1150>. If the dicarbonyl compound is Meldmm s acid, however, the sequence is completed by spontaneous elimination of acetone and carbon dioxide from the Diels-Alder adduct, to give compound 95 <2005ASC1353>. 

Another example of the formation of a 3,6-anhydro ring by the saponification of a 3-tosyl-D-glucose derivative is furnished by the work of Peat and Wiggins11 who were able to isolate derivatives of no less than three anhydro sugars, one of which was 3,6-anhydro-D-glucose, from the... 

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