Acetyl hydration

X-ray, 4, 160 (79AX(B)2228> lH-Pyrrole-2,4-diamine, 1-t-butyl-JV, JV -dimethyl-3-phenyl-JV -phenylsulfonyl-X-ray, 4, 160 (78BSB893) lH-Pyrrole-3-methanol, 4-acetyl-X-ray, 4, 160 (78AX(B)1248> lH-Pyrrole-3-methanol, 4-acetyl-, hydrate X-ray, 4, 160 (78AX(B)1248> lH-Pyrrole-3-propanoic acid, ester C NMR, 4, 172 (74JCS(P2)1004>... 

H-Pyrrole-3-methanol, 4-acetyl-, hydrate X-ray, 4, 160 <78AXpropanoic acid, ester C NMR, 4, 172 <74JCS[Pg.55]

Aootlo acid—Acetyl hydrate—ffydrogen acetate—PyroligneouB add— Acidum aceticum (U. 5./ J9r.)—CH,0O,OH—60. 

Acetic acid—Acetyl hydrate—Hydrogen acetate—Pyroligneous acid—Acidum aceticum (TJ. S. Br.)—CEa,COOH—60. 

The higher iodides, however, tend to be unstable and decomposition occurs to the lower iodide (PI5 -> PI3). Anhydrous chlorides and bromides of some metals may also be prepared by the action of acetyl (ethanoyl) halide on the hydrated ethanoate (acetate) in benzene, for example cobalt(II) and nickel(II) chlorides ... 

Excellent results may be obtained by conducting the acetylation in aqueous solution (cf. Section IV,45). Dissolve 0-5 g. of the amine in 2N hydrochloric acid, and add a little crushed ice. Introduce a solution of 5 g. of hydrated sodium acetate in 25 ml. of water, followed by 5 ml. of acetic anhydride. Shake the mixture in the cold until the smell of acetic anhydride disappears. Collect the solid acetyl derivative, and recrystallise it from water or dilute alcohol. 

Acetyl-3-mercaptopropanol reacts with acetaldehyde in the presence of hydrazine hydrate to yield 2,4-dimethyl-5-(/3-hydroxyethyl)thiazole (10), R, = Rj = Me, R3 = CH2CH2OH (556). 

Chemists and biochemists And it convenient to divide the principal organic substances present m cells into four mam groups carbohydrates proteins nucleic acids and lipids Structural differences separate carbo hydrates from proteins and both of these are structurally distinct from nucleic acids Lipids on the other hand are characterized by a physical property their solubility m nonpolar solvents rather than by their structure In this chapter we have examined lipid molecules that share a common biosynthetic origin m that all their carbons are derived from acetic acid (acetate) The form m which acetate occurs m many of these processes is a thioester called acetyl coenzyme A... 

The Hydrate and Enol Form. In aqueous solutions, acetaldehyde exists in equihbrium with the acetaldehyde hydrate [4433-56-17, (CH2CH(0H)2). The degree of hydration can be computed from an equation derived by BeU and Clunie (31). Hydration, the mean heat of which is —21.34 kJ/mol (—89.29 kcal/mol), has been attributed to hyperconjugation (32). The enol form, vinyl alcohol [557-75-5] (CH2=CHOH) exists in equihbrium with acetaldehyde to the extent of approximately 1 molecule per 30,000. Acetaldehyde enol has been acetylated with ketene [463-51-4] to form vinyl acetate [108-05-4] (33). 

Acetates. Anhydrous iron(II) acetate [3094-87-9J, Ee(C2H202)2, can be prepared by dissolving iron scraps or turnings in anhydrous acetic acid ( 2% acetic anhydride) under an inert atmosphere. It is a colorless compound that can be recrystaUized from water to afford hydrated species. Iron(II) acetate is used in the preparation of dark shades of inks (qv) and dyes and is used as a mordant in dyeing (see Dyes and dye intermediates). An iron acetate salt [2140-52-5] that is a mixture of indefinite proportions of iron(II) and iron(III) can be obtained by concentration of the black Hquors obtained by dissolution of scrap iron in acetic acid. It is used as a catalyst of acetylation and carbonylation reactions. 

Iron Sulfur Compounds. Many molecular compounds (18—20) are known in which iron is tetrahedraHy coordinated by a combination of thiolate and sulfide donors. Of the 10 or more stmcturaHy characterized classes of Fe—S compounds, the four shown in Figure 1 are known to occur in proteins. The mononuclear iron site REPLACE occurs in the one-iron bacterial electron-transfer protein mbredoxin. The [2Fe—2S] (10) and [4Fe—4S] (12) cubane stmctures are found in the 2-, 4-, and 8-iron ferredoxins, which are also electron-transfer proteins. The [3Fe—4S] voided cubane stmcture (11) has been found in some ferredoxins and in the inactive form of aconitase, the enzyme which catalyzes the stereospecific hydration—rehydration of citrate to isocitrate in the Krebs cycle. In addition, enzymes are known that contain either other types of iron sulfur clusters or iron sulfur clusters that include other metals. Examples include nitrogenase, which reduces N2 to NH at a MoFe Sg homocitrate cluster carbon monoxide dehydrogenase, which assembles acetyl-coenzyme A (acetyl-CoA) at a FeNiS site and hydrogenases, which catalyze the reversible reduction of protons to hydrogen gas. 

With Acyl Halides, Hydrogen Halides, and Metallic Halides. Ethylene oxide reacts with acetyl chloride at slightly elevated temperatures in the presence of hydrogen chloride to give the acetate of ethylene chlorohydrin (70). Hydrogen haUdes react to form the corresponding halohydrins (71). Aqueous solutions of ethylene oxide and a metallic haUde can result in the precipitation of the metal hydroxide (72,73). The haUdes of aluminum, chromium, iron, thorium, and zinc in dilute solution react with ethylene oxide to form sols or gels of the metal oxide hydrates and ethylene halohydrin (74). 

The hydration of 5-amino-3-cyano-l-(2,6-dichloro-4-trifluoromethylphenyl)-4-ethynylpyrazole was performed with p-toluenesulfonic acid monohydrate in acetonitrile (2 h, room temperature) to give the corresponding 4-acetyl derivative. An alkyl substituent at the triple bond decreases the rate of hydration the conversion of 5-amino-3-cyano-l-(2,6-dichloro-4-trifiuoromethylphenyl)-4-(prop-l-yn-l-yl) pyrazole to the 4-propanoylpyrazole was completed after 18 h (98INP9804530 99EUP933363). 

Acetyl-l 2-ketochenodeoxycholic acid Hydrazine hydrate Potassium hydroxide... 

To 1,400 ml of an approximately 50% water/triglycol solution of the potassium salt of cheno-deoxycholic acid, obtained by the Wolff-Kishner reduction (using hydrazine hydrate and potassium hydroxide) from 50 g of 7-acetyl-12-ketochenodeoxycholic acid, 220 ml of dilute hydrochloric acid is added to bring the pH to 2. The solution is stirred and the crude cheno-deoxycholic acid precipitates. The precipitate is recovered and dried to constant weight at about 60°C. About 36 g of the crude chenodeoxycholic acid, melting in the range of 126°-129°C, is obtained. 

Clearly compound 26 (R = Ac) had undergone a reaction analogous to the glycal rearrangement. It has been demonstrated that the rearrangement of this compound also occurs at room temperature in acetic anyhydride in the presence of zinc chloride (34). Under these conditions, however, a further slower isomerization takes place and a third product, assigned the acetylated enone-hydrate structure 29, was isolated. As noted later this structure has been shown to be incorrect. 

The amino acid leucine is biosynthesized from n-ketoisocaproate, which is itself prepared from -ketoisovalerate by a multistep route that involves (1) reaction with acetyl CoA, (2) hydrolysis, (3) dehydration, (4) hydration. (5) oxidation, and (6) decarboxylation. Show lhe steps in the transformation, and propose a mechanism for each. 

Tin, nitratodiphenyltris(dimethy) sulfoxide)-structure, 1,77 Tin, nitratotris(triphenyltin)-structure, 1, 47 Tin,tetrakis(acetato)-stereochemistry, 1,94 Tin, tetrakis(diethyldithiocarbamato)-angular parameters, 1, 57 Tin, tetrakis(ethyldithiocarbamato)-angular parameters, 1, 57 Tin, tetranitrato-stereochemistry, 1, 94 Tin, tri-n-butylmethoxy-, 3, 208 Tin alkoxides physical properties, 2, 346 Tin bromide, 3, 194 Tin bromide hydrate, 3,195 Tin carboxylates, 3, 222 mixed valence, 3, 222 Tin chloride, 3, 194 hydroformylation platinum complexes, 6, 263 Tin chloride dihydrate, 3,195 Tin complexes, 3, 183-223 acetyl ace tone... 

Tetra Acetyl Glucosone Hydrate. A Novel Route to the Syntheses of Analogues of Ascorbic Acid and a Possible Mechanism for the Transformation of Hexoses into Kojic Acid, M. Stacey and L. M. Turton, J. Chem. Soc., (1946) 661 -664. 

Grant, J. A., R. L. Williams, and H. A. Scheraga. 1990. Ab Initio Self-Consistent Field and Potential-Dependent Partial Equalization of Orbital Electronegativity Calculations of Hydration Properties of N-Acetyl-N -Methyl-Alanineamide. Biopolymers 30, 929-949. 

Various fully-acetylated monosaccharides and disaccharides or sugar alcohols are readily separable by chromatographic adsorption on Mag-nesol (a hydrated magnesium acid silicate)111 and the unacetylated substances may be separated on clay columns.112... 

The use of mesitoic acid esters has again been successfully employed by Burrows and Topping (1975) in the elucidation of intramolecular carbon acid participation. Under basic aqueous conditions, 2-acetylphenyl mesitoate [41] hydrolyses to yield mesitoic acid and 2-hydroxyacetophenone, reacting with intramolecular catalysis via the monoanion of the ketonic hydrate (see p. 192). However, in 47.5% aqueous ethanol containing potassium hydroxide, the reaction products from l-acetyl-2-naphthyl mesitoate [45] were found... 

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