Diacetamide compounds

The Wohl degradation can be considered to consist of two steps (a) the elimination of the acetyl and nitrile groups by the action of ammonia or ammoniacal silver oxide, and (b) the formation of the diacetamide compound. The formation of the latter was explained by Wohl on the basis of the intermediate formation of oIde%do-D-arabinose... 

The diacetamide compounds were regularly obtained in all degradations employing ammonia with or without silver oxide until Hockett and Chandler applied the method to hexaacetyl-D-gluco-D-flruZo-heptono-nitrile (XLIX) and obtained a monoacetamide derivative that was identified as iV-acetyl-D-glucofuranosylamine (L). The furanose structure of L was established by lead tetraacetate oxidation. They... 

An indication of the sensitivity of the reaction to changes in the structure of the acylated nitrile is furnished by the work of Neuberg and Wolff, who obtained hydrocyanic acid from the Wohl degradation of pentaacetyl-D-glucosaminonitrile, but could not obtain a diacetamide compound. 

Recently Isbell and Frush have given an interpretation of the reactions leading to the formation of the diacetamide compounds. They admit that an aldehyde group is necessary. 

D-Fucose (Rhodeose). Voto6ek obtained tetraacetyl-D-fucononitrile in 25% yield by treating D-fucose oxime with sodium acetate-acetic anhydride. The nitrile, degraded with ammonia and silver oxide, yielded 5-desoxy-D-lyxose diacetamide in 40% yield. The diacetamide compound was hydrolyzed with 5% hydrochloric acid and the 5-desoxy-D-lyxose was obtained in solution and characterized as the p-bromo-phenylosazone. Hydrolysis of the diacetamide compound with 6 N sulfuric acid was realized by Voto6ek and Valentin and the 5-desoxy-D-lyxose was isolated as a sirup. 

The degradation procedure devised by Wohl 188) is essentially the reverse of the cyanohydrin synthesis. It involves the removal of the cyanide group from the acetylated nitriles, which in turn are formed from the oximes by application of the usual acetylation procedures. In the original process, the cyanide group was eliminated by the action of ammoniacal silver oxide. Under these conditions, the diacetamide compound of the low-er sugar results, and the free sugar is obtained from it by acid hydrolysis. 

According to Hockett and Chandler, the hydrolysis of an acetylated nitrile (LIII) results in the formation of an acetylated aldehydo sugar (LIV). If this compound then undergoes ammonolysis at carbon atoms 2 or 3, the formation of diacetamides is to be expected, since hemiacetal formation involving the C2 or C3 hydroxyl group is unknown. The... 

D-Threose diacetamide. (Aqua ammonia.) Thirty grams of tetraacetyl-o-xylononitrile was mixed with 300 ml. of concentrated aqua ammonia (28-29 %) and warmed on a water bath until the solid was all dissolved, and then allowed to stand for three hours. The solution was concentrated in vacuo to a thick sirup, which was dissolved in aqua ammonia and reconcentrated. The final thick sirup was dissolved in absolute ethanol and ether added to the point of turbidity. After forty-eight hours in a refrigerator the crystals which had formed were collected yield, 16.5 g. (78%). They were recrystallized by dissolution in two volumes of warm 75 % ethanol, filtration through carbon and the addition of an equal volume of absolute ethanol. The compound crystallized slowly, forming clear, sharp needles or prisms in resets, m. p. 165-167. ... 

Diacetamides are oxidized by lead tetraacetate, and Hockett and coworkers have studied the behavior of a number of these compounds. 

Other studies include Taketa s series (1993, 1992) on oxyacids, from which he concludes that these compounds are polymerized via H bonds. Puchalik (1676) used surface tension (and other tests) to show that the interaction in ethanol-water mixtures is greater than in the pure alcohol. Early work on this system (2086) showed it to be abnormal at medium concentration. As a final example, we mention some of the compounds such as the hydrated forms Glagoleva (775, 774) suggested for formic and acetic acids, and those Dunn and Polya presented for the interaction of acetamide and diacetamide (566). 

Amino-4 -acetamidodiphenylamine-4-arsinic acid forms irregular, flat needles, acetylation yielding 2 i -diacetamid()di2 lienyl-a iitte-4i-arsinic acid, which crystallises in fine, colourless needles from dilute acetic acid. Hydrolysis of the latter compound yields 2 4> -di-amiiiodiphenylamine-i-arsinic acid, crystallising in long, slender prisms. 

The compounds formed by the replacement of hydrogen atoms by acyl radicals are called amides. Acetamide, CH3CO.NH2, diacetamide, (CH3CO)2NH, and triacetamide (CH3C0)3N, are examples of the three classes of compounds which exist. Of the amides only those which contain one acyl group will be considered here. 

GaMe3 reacts with diacetamide to give (69). H n.m.r. and some i.r. and Raman data (partly assigned) have been listed for this compound... 

Few stable complexes of alkali metals have been reported. Complexes of the alkali metals with j -diketone derivaties, o-nitrophenol, and sali-cylaldehyde have been described in the literature.The sodium compounds ranged from hydrated ionic salts such as Na (acac)-2 H2O to adducts like Na(Sal) HSal (HSal = Salicylaldehyde). PfeiflFer and others have reported the isolation of a complex of sodium perchlorate with 1,10-phenan-throline. Brady and Badger have presented evidence for chelation in sodium salts of o-hydroxybenzaldehydes. More recently, Popp and Joesten have isolated and characterized a number of alkali metal and alkaline earth metal salts with the ligand octamethylpyrophosphoramide (OMPA). Gentile and co-workers have also reported complexes of diacetamide with alkali and alkaline earth metal salts. 

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