Carbon atoms, in sugars

A sugar, either D-ribose or D-2-deoxyribose. Carbon atoms in sugars are numbered l -5/... 

Most of the carbon atoms in sugars have a tetrahedral geometry. Therefore, sugar molecules are not flat, but have a three-dimensional structure. The three-dimensional structure of carbohydrates is commonly depicted using Fischer projections, named in honor of Emile Fischer. Fischer worked out the structures of most of the carbohydrates in the first part of the twentieth century with little... 

Some of these reactions are essentially quantitative and are even used in analytical chemistry (e.g. benzal of pentaerithritol)3) or to introduce protective groups in the synthesis of nucleic acids or sugars (reactions of hydroxyl groups at adjacent carbon atoms in sugar with acetone or benzaldehyde)4). 

Torsion angles around bonds j-k where j and k denote carbon atoms in sugar rings are treated in a special manner ... 

The simple sugars or monosaccharides are polyhydroxy aldehydes or ketones, and belong to Solubility Group II. They are termed tetroses, pentoses, hexoses. etc. according to the number of carbon atoms in the long chain constituting the molecule, and aldoses or ketoses if they are aldehydes or ketones. Most of the monosaccharides that occur in nature are pentoses and hexoses. 

Perhaps the earliest report of the replacement of a sulfonate ester attached to a secondary carbon atom in a sugar derivative was that of Helferich (53). Under quite drastic conditions (sodium iodide in acetone, 105°C., 72 hours, sealed system) the 4-mesylate derivative 9 was converted into a crystalline 4-deoxy-4-iodo sugar derivative 10 in 46% yield. Although the position of the iodine atom was established, the configuration at C-4 was not known. 

Conformational depictions of acyclic sugar chains are conveniently expressed by locating certain atoms in the plane of the paper and orientating the remaining atoms or groups appropriately above and below that plane, as shown for D-arabinitol and xylitol (it should be recognized that the favoured conformation does not necessarily have all the carbon atoms in the same plane) ... 

The problems of anomeric equilibrium may be avoided by investigating 2-ketoses. Both a hydroxyl group and a hydroxymethyl group are attached to the anomeric carbon atom in such sugars, and the bulky hydroxymethyl group favors the equatorial position. These authors measured c.d. spectra for three ketoses, the 2-(hydroxymethyl) derivatives of a-L-xylose, a-D-xylose, and a-D-mannose, in aqueous solution. 

C13-0016. The six-carbon sugar j6-mannose is identical to a-glucose except at carbon atoms in... 

A nucleic acid is a long polymeric atom on one of the carbon atoms in the ring of the ribose sugar are deoxyrib-... 

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