D-Glucose, derivatives

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... 

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

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

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... 

Most of the selective-etherification studies on polysaccharides have been made with cellulose, and nearly all of them have involved quantitative separation of the D-glucose derivatives formed on hydrolysis of the partially substituted celluloses. In view of their stability, ethers of polysaccharides are particularly suited to this approach. 

For the synthesis of D-glucuronic acid, methods of oxidation of suitable D-glucose derivatives have been devised during the past two decades these procedures have been comprehensively reviewed by Marsh,6 Mehltretter,7 and Heyns and Paulsen.8 For special purposes, for example, for the preparation of 6-I4C-labelled D-glucuronic acid, chain-extension reactions of 1,2-O-isopropylidene-a-D-xy/o-pen-todialdo-I,4-fiiranose by the cyanohydrin synthesis9 or by ethynyla-tion10 are used, but these frequently yield mixtures of D-glucuronic acid and L-iduronic acid. 

Fig. 2 Two possible biosynthetic pathways to pyrethrolone. The [l-13C]D-glucose-derived 13C labels that occur in the mevalonic acid and 2-C-methyl-D-erythritol 4-phosphate (13) pathways are colored in red and green, respectively. The phosphate moiety is indicated as P ...

Scheme 5.73 Selective preparation of 2-substituted glucosides via 1,6-anhydro-D-glucose derivatives.

Kambe and Yasuda19 discovered the effectiveness of the fluoride as a Henry reaction catalyst. Since then, the use of diverse fluorides is a common method to catalyze nitro aldol condensations, since they provide mild conditions that are particularly convenient for sensitive products as carbohydrates. The most common fluorides are potassium fluoride20 and tetrabutyl ammonium fluoride.21 A recent example relates to the TBAF catalyzed addition of nitroethanol to the D-glucose derivative 18, to give nitro sugars 19 (Scheme 8).22... 

However, this multistep procedure is experimentally complex. A simpler variation described in 199127 consists of the reaction of an aldehyde and a nitro compound in the presence of triethylamine, TBAF and tert-butyl-dimethylsilyl chloride. Under these conditions, nitro sugars are obtained in good yieds and higher diastereoselectivities than those afforded by the standard conditions. This procedure was used in several synthesis of 2-nitro-2-deoxyaldoses, as for the condensation of l,l-diethoxy-2-nitroethane and l,2 3,4-di-0-isopropylidene-a-D-galacto-hexodialdo-l,5-piranose.28 More recently, it was applied to the addition of ethyl nitroacetate to the D-glucose derived aldehyde 18, to give nitro sugar derivatives 26, key precursors of polysubstituted cyclohexane a-amino acids (Scheme 10).29... 

Intramolecular Henry reactions of nitro sugars are usually diastereo-selective sometimes a single isomer results from an epimeric mixture, on account of the reversivility of the Henry reaction, which allows equilibration through open chain intermediates.49 A recent example involving the D-glucose derived nitro acid ester 26 is shown in Scheme 22. 

Fig. 16.— 13C-N.m.r. Spectra of Polysaccharides (in DsO) Containing (1— 3)- and (1—>4)-Linked /3-D-Mannopyranosyl Residues, Obtained from [2H]-Labelled D-Glu-coses. (Temperature, 70° chemical shifts expressed as 8C, relative to external tetra-methylsilane the number marked with a superscript asterisk refers to the position of labelling in each D-glucose derivative.)...

Scheme 2.4 Accessible, tautomericaUy fixed D-glucose derivatives with which to embark toward versatile building blocks. ...

We reported a catalytic enantioselective cyanosUylation of ketones that produces chiral tetrasubstituted carbons from a wide range of substrate ketones [Eq. (13.31)]. The catalyst is a titanium complex of a D-glucose-derived ligand 47. It was proposed that the reaction proceeds through a dual activation of substrate ketone by the titanium and TMSCN by the phosphine oxide (51), thus producing (l )-ketone cyanohydrins ... 

Fig. 16 Cycloaddition reaction of 0-allyl derivative of D-glucose derives aldehyde with aniline...

By 1920, it was recognized that a successful chemical synthesis would probably require the use of a D-fructose maintained in the proper cyclic structure by the presence of substituents. The substituent groups would have to be stable enou to survive the conditions required in condensation with a suitable D-glucose derivative, but at the same time be capable of ready removal by agents that failed to affect any sucrose... 

In the case of the above mentioned benzoyl-D-glucose derivatives a correlation was found between the formation of D-glucose dibenzamide and the permanent or transitory existence of a free aldehyde group. The same behavior was noted for triacetyl-oZdehydc-L-erythrose (XLI), which by the action of ammonia produces L-erjrthrose diacetamide (XLII). Isbell and Frush have obtained a similar result in the case of tetraacetyl-oWe/it/do-L-arabinose which, when treated with methanolic ammonia, gave L-arabinose diacetamide in 53 % yield. 

In work on enzymic deacetylation, a series of D-glucose derivatives acetylated at specific positions was prepared, and the O-trimethylsilyl derivatives of these D-glucose acetates were separated by gas-liquid chromatography.352,353 Research on bacterial glycolipids required the characterization of 3- and 6-O-palmitoyl-D-glucose, the separation of which, as their O-trimethylsilyl and acetyl derivatives, was studied.354... 

Karkkainen and Vihko,144 in their work cited earlier, also studied the O-trimethylsilyl derivatives of acetamidodeoxyhexoses. Of the two liquid phases that they used, they found QF-1 more suitable for the separation of anomers, but SE-30 was better for separating 2-amino-2-deoxy-D-glucose derivatives from those of2-amino-2-deoxy-D-galactose. 

The strain of Agrobacterium tumefaciens capable of oxidizing D-glucose derivatives at C-3 was found to convert uridine 5 -(a-D-glucopyranosyl pyrophosphate) into the a-D-nfco-hexopyranosyl-3-ulose derivative264 (54). 

The association between Drs. Fletcher and Pravdic, which started when she was a Visiting Scientist at the Institute in Bethesda, continued after she returned to Yugoslavia. Together they investigated the chemistry of unsaturated 2-acetamido-2-deoxy-D-glucose derivatives, and, with Emmanuel Zissis, the preparation of lactones from these sugars, work stemming from Dr. Fletcher s interest in Tay-... 

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