Sugars That Contain Nitrogen

This Chapter will discuss the formation of heterocycles that contain nitrogen and that involve atoms of the original sugar, and not the combination of existing heterocycles with saccharide derivatives. Thus, for example, the synthesis of nucleosides will not be included, but the formation of anhydronucleosides, in which a new heterocyclic ring has been introduced into the molecule, will be treated. 

A number of anhydro sugars are known that contain nitrogen, sulfur, or selenium. Tri-O-acetyl thioglucosan was first prepared in 1963 by Akagi and co-workers by treatment of S-gluco-syl dithiocarbonate (21 O Fig. 2) with sodium methoxide [74]. Since that time, numerous syntheses have been reported that rely on the introduction of a thioester at C-1 or C-6 and the activation of the alternate position with a halide or sulfonate group [75,76]. Treatment of a doubly activated hexopyranose such as (24) with hydrogen sulfide and triethylamine... 

XI. SUGARS THAT CONTAIN EXOCYCLIC NITROGEN (other than — NH2 derivatives)... 

Construct an artificial RNA nucleotide made from a fragment derived from the ribose sugar and modular fragments of sulfuric acid and an unnatural base. Restrict your choice to a base that contains nitrogen (see the natural bases in the text). Show your chosen fragments and the construction process. 

A nucleic acid is an organic compound, either RNA or DNA, whose moiecuies carry genetic information and which is made up of one or two chains of monomer units caiied nucieotides. However, unlike the monomer units in polysaccharides and polypeptides, each nucleotide monomer can he further hydrolyzed into three different molecules. A nucleotide molecule is composed of a five-carhon sugar unit that is bonded to both a phosphate group and a cycHc, organic base that contains nitrogen. 

Nucleic acids are the molecules in our cells that direct and store information for reproduction and cellular growth. There are two types of nucleic acids ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). Both of these nucleic acids are unbranched organic polymers composed of monomer units called nucleotides. These nucleotides are composed of a sugar molecule, a nitrogen base, and phosphoric acid. A single DNA molecule may contain several million of these nucleotides, while the smaller RNA molecules may contain several thousand. 

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