Acetic anhydride-Sodium acetate

Acetyl chloride Sodium acetate Acetic anhydride... 

In the case of the oximes of the aldose sugars, the situation is more complicated because of the possibility of both open-chain and cyclic structures. That aldose oximes can react in the open-chain form follows from the formation of the nitriles and from the isolation of acylated open-chain aldose oximes as secondary products in preparation of nitriles. For example, Wolfrom and Thompson, by the action of sodium acetate-acetic anhydride on n-glucose oxime, not only obtained pentaacetyl-D-glucononitrile, in 40% yield, but also isolated a small amount of hexaacetyl-oWeAydo-D-glucose oxime (V) identical with that prepared by mild acetylation of pentaacetyl-aWe%do-D-glucose oxime (IV) whose structure was assured by its formation from pentaacetyl-aldehydo-D-glucoae (III). 

This hexaacetyl-aWe%do-D-glucose oxime was easily transformed into the nitrile by heating at 135-140 , or by treatment with sodium acetate-acetic anhydride, and Wolfrom and Thompson considered the open-chain oxime and its acetylated derivative to be an intermediate in the production of the nitrile. We have no proof of the original structure of the oxime. Under the conditions of temperature employed, even a syn oxime can be transformed into the nitrile. If we accept the assumption that the isolated open-chain oxime is the only intermediate, its... 

Acetylated aldose oximes with a ring structure have also been obtained during the preparation of the nitriles, both with sodium acetate-acetic anhydride and with pyridine-acetic anhydride. Thus it appears that under these conditions at least a certain amount of the oxime is present in the ring form. 

D-Xylose. Maquenne obtained tetraacetyl-D-xylononitrile in 41% 3deld from the D-xylose employed, by treatment of the oxime with sodium acetate-acetic anhydride. From the nitrile, D-threose diacetamide was obtained in 30 % yield by the action of ammonia and it was hydrolyzed... 

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. 

D-Glucose. WohP obtained pentaacetyl-n-glucononitrile in 40% yield by the action of sodium acetate-acetic anhydride. The nitrile when treated with ammonia-silver oxide gave a 47 % yield of n-arabinose diacetamide. Hydrolysis of the diacetamide derivative with 6 N sulfuric acid produced crystalline n-arabinose in 50-60 % yield. The process was improved by Neuberg and Wohlgemuth, who obtained n-arabinose in an over-all yield of 34.7 % of the n-glucose employed. 

Isopropyl ester of 6-formyl-5-methoxycarbonyl-2-methyl-4-(3-nitrophenyl)-l,4-dihydropyridine-3-carboxylic acid Hydroxylamine hydrochloride Sodium acetate Acetic anhydride... 

Lastly, aromatization of the dienone (103), in sodium acetate-acetic anhydride at 140 °C, proceeds by a Favorskii-style mechanism, to afford (104), ... 

Biphenyl-2,2 -dicarboxylic acids are oxidatively converted into benzocoumarins with loss of carbon dioxide. A more predictable reaction of a dicarboxylic acid occurs on heating with sodium acetate-acetic anhydride C-acetylation first occurs and decarboxylative lactonization follows, but in low yield. 

The reactions shown in this section illustrate the versatility of Af-substituted pyridines in the synthesis of condensed heterocycles containing pyrrole. Some of the cyclizations proceed without the need for externally applied heat [2419, 2422,2830,2980a], and for most of the cyclizations, the conditions are relatively mild. The preformed ylide is used in some of the reactions while in others, it is generated in situ. It is even possible to react a 2-methylpyridine with an Af-alkyl-ating agent, such as bromoacetone, and then cyclize the intermediate iV-alkyl derivative by heating with sodium acetate-acetic anhydride or carbonate without isolating either the intermediate. /V-alkylpyridine or the ylide [2157, 2295, 2393, 3512]. 

Treatment of cancentrine methiodide with sodium acetate-acetic anhydride under reflux for 48 hr produced about equal amounts of two compounds, 10 and 11, of molecular formula C37H2gNOg and C42H38lSr209, respectively (r). 

Sodium acetate acetic anhydride N-Condensed pyridone ring 794. O... 

Sodium acetate/acetic anhydride CHgCOONa/(CHgCO... 

C-1. The product distribution was found to depend upon the amount of water present in the system, more 6-(bromomethylene)cyclodecanone being obtained with less water present. This observation was explained in terms of capture of the carbonium ion formed from (56 = 2). There would seem to be no examples yet where an intramolecular shift process competes with ring-opening of a cyclopropyl cation. Solvolysis of 10,10-dibromo[4,3,l]propellane in acetic acid-sodium acetate-acetic anhydride gave products formed via the strained bicyclic acetate (56 n = 1, R = Ac). In the absence of acetic anhydride products derived from the corresponding alcohol (56 n = 1, R — H) were obtained as well. Solvolyses of 10,10-dibromo[4,3,l]propell-3-ene in acetic acid-sodium acetate, in the presence and absence of acetic anhydride, and in acetic acid-silver perchlorate, were also reported. Most of the products may have been formed by reaction pathways similar to those observed for (55). ... 

Method Seven, Sasaki (677). 3,6-Dibenzal-2 diketopiperasine (A) is prepared in 62% yield from benaaldehyde, sodium acetate, acetic anhydride and 2,5-diketopiperazine. DD-Phenylalanine is prepared in 83% yield by reduction of (A) to the intermediate 3,6-dibenzyl-2,5-diketo-piperasine (B) vrith BQ and red phosphorus and simultaneous hydrolysia of (B). The over-all yield is 60%. 

Sodium acetate/acetic anhydride Preferential C-decarbalkoxylation COOR H... 

The (Z)-isomer (245) of l-0-acetyl-2,3 4,5-di-0-isopropylidene-D-cr> //iru-pent-l-enitol was obtained on heating 2,3 4,5-di-0-isopropylidene- W /fyi u-D-arabinose or the o-ribose analogue with an excess of acetic anhydride containing sodium acetate. Acetic anhydride and sodium acetate also converted 2,3 4,5-di-<9-isopropylidene- W Ayf/o-D-xylose into the (Z)-D-//zA-eo-pent-1-enitol (246), which, like (245), could be photoisomerized to the ( )-isomer. 

Sodium acetate/acetic anhydride Benz-3,1-oxazines s. U, 328... 

Zinc sodium acetate acetic anhydride Zn/CHgCOONal(CH CO... 

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