Acetic butyryl

Fig. 5. Composition of cellulose acetate butyrate (propionate) as a function of butyryl (propionyl) content of esterification bath.

Acetyl, % Butyryl, % Hydioxyl, % Acetate Butyrate Hydroxyl AppHcation... 

Cellulose acetate butyrates with high butyryl content and low viscosity are soluble in inexpensive lacquer solvents. They are widely used in lacquers for protective and decorative coatings appHed to automobiles and wood furniture. 

An alcohol-soluble cellulose acetate butyrate containing ca 50% butyryl and ca 4.5% hydroxyls available commercially. 

Low viscosity cellulose propionate butyrate esters containing 3—5% butyryl, 40—50% propionyl, and 2—3% hydroxyl groups have excellent compatibihty with oil-modified alkyd resins (qv) and are used in wood furniture coatings (155). Acetate butyrate esters have been used in such varied apphcations as hot-melt adhesive formulations (156), electrostatically spray-coated powders for fusible, non-cratering coatings on metal surfaces (157—159), contact lenses (qv) with improved oxygen permeabiUty and excellent wear characteristics (160—162), and as reverse-osmosis membranes for desalination of water (163). 

Sen and Kakaji synthesized a series of 4-butyrylnaphthocoumarins 48 from l-butyryl-2-naphthols 49 using acetic anhydride and two homolog anhydrides in excellent yields. They also showed that l-propionyl-2-naphthols and l-acetyl-2-naphthols could be converted to their corresponding coumarins using the same three anhydrides. However, l-acetyl-2-naphthol in the presence of acetic anhydride and sodium acetate gave a chromone not a coumarin. 

Acetic acid, butyryl-, ethyl ester [Hexanoic acid, 3-oxo-, ethyl ester] 55, 73, 75 Acetic acid, chloro-, tert-butyl ester [Acetic acid, chloro- 1,1-dimethylethyl ester], 55,94... 

One of the simplest ways to prepare a chitin gel is to treat chitosan acetate salt solution with carbodiimide to restore acetamido groups. Thermally not reversible gels are obtained by AT-acylation of chitosans N-acetyl-, N-propionyl- and N-butyryl-chitosan gels are prepared using 10% aqueous acefic, propionic and bufyric acid as solvents for treatment with appropriate acyl anhydride. Both N- and 0-acylation are found, but the gelation also occurs by selective AT-acylation in the presence of organic solvents. 

Acetic anhydride Propionic anhydride Butyric anhydride Maleic anhydride Phthalic anhydride Acetyl chloride Propionyi chloride Butyryl chloride Hexonyl chloride Benzoyl chloride Oxalyl chloride Chloroacetyl chloride Dichloroacetyl chloride Trichloroacteyl dtloride... 

These short-chain fatty acids are acetic, butyric, lactic and propionic acids, also known as volatile fatty acids, VFA. They are produced from fermentation of carbohydrate by microorganisms in the colon and oxidised by colonocytes or hepatocytes (see above and Chapter 4). Butyric acid is activated to produce butyryl-CoA, which is then degraded to acetyl-CoA by P-oxidation acetic acid is converted to acetyl-CoA for complete oxidation. Propionic acid is activated to form propionyl-CoA, which is then converted to succinate (Chapter 8). The fate of the latter is either oxidation or, conversion to glucose, via glu-coneogenesis in the liver. 

The cholinesterases, acetylcholinesterase and butyrylcholinesterase, are serine hydrolase enzymes. The biological role of acetylcholinesterase (AChE, EC 3.1.1.7) is to hydrolyze the neurotransmitter acetylcholine (ACh) to acetate and choline (Scheme 6.1). This plays a role in impulse termination of transmissions at cholinergic synapses within the nervous system (Fig. 6.7) [12,13]. Butyrylcholinesterase (BChE, EC 3.1.1.8), on the other hand, has yet not been ascribed a function. It tolerates a large variety of esters and is more active with butyryl and propio-nyl choline than with acetyl choline [14]. Structure-activity relationship studies have shown that different steric restrictions in the acyl pockets of AChE and BChE cause the difference in their specificity with respect to the acyl moiety of the substrate [15]. AChE hydrolyzes ACh at a very high rate. The maximal rate for hydrolysis of ACh and its thio analog acetyl-thiocholine are around 10 M s , approaching the diffusion-controlled limit [16]. 

The following abbreviations are used in this and the subsequent tables Ac for acetyl, Pr for propionyl, Bu for butyryl, Bz for benzoyl, Ts for tosyl, My for methylene, Ed for ethylidene, Bd for benzylidene, Fd for furfurylidene. Id for isopropylidene, Me for methyl, Et for ethyl, Be for benzyl, Tr for trityl and Az for azoyl. Where the linkages of acetals and ketals are known, they are shown by different type fonts.)... 

Methyl acetate probably originates from the reaction of methanol with the intermediate cobalt-acyl complex. The reaction leading to the formation of acetaldehyde is not well understood. In Equation 8, is shown as the reducing agent however, metal carbonyl hydrides are known to react with metal acyl complexes (20-22). For example, Marko et al. has recently reported on the reaction of ri-butyryl- and isobutyrylcobalt tetracarbonyl complexes with HCo(CO) and ( ). They found that at 25 °C rate constants for the reactions with HCo(CO) are about 30 times larger than those with however, they observed that under hydroformylation conditions, reaction with H is the predominant pathway because of the greater concentration of H and the stronger temperature dependence of its rate constant. The same considerations apply in the case of reductive carbonylation. Additionally, we have found that CH C(0)Co(C0) L (L r PBu, ... 

Acenaphthylene, 58, 73 Acetaldehyde, 58, 157 Acetamides, arylalkyl-, 56, 7 Acetanilide, 2,2,2-tnfluoro-, 56, 122 Acetic acid, butyryl-, ethyl ester, 55,73,... 

Synthesis (Kleemann et al. 1999, Janssen (Janssen), 1973 Janssen et al. (Janssen), 1973, Stokbroekx et al., 1973, Niemegeers et al., 1974) ) Treatment of 2-oxo-3,3-diphenyl-tetrahydrofuran, synthesized by treatment of diphenyl-acetic acid ethyl ester with ethylene oxide, with HBr(gas) yields bromo derivative i, which is then converted into butyryl chloride derivative ii by means of thionyl chloride in refluxing chloroform. Reaction of derivative ii with dimethylamine in toluene affords dimethyl (tetrahydro-3,3-diphenyl-2-furylidene)ammonium bromide, which is then condensed with 4-(4-chlorophenyl)-4-piperidinol by means of Na2C03 and Kl in refluxing 4-methyl-2-pentanone to provide loperamide. 

In the ruminant mammary tissue, it appears that acetate and /3-hydroxybutyrate contribute almost equally as primers for fatty acid synthesis (Palmquist et al. 1969 Smith and McCarthy 1969 Luick and Kameoka 1966). In nonruminant mammary tissue there is a preference for butyryl-CoA over acetyl-CoA as a primer. This preference increases with the length of the fatty acid being synthesized (Lin and Kumar 1972 Smith and Abraham 1971). The primary source of carbons for elongation is malonyl-CoA synthesized from acetate. The acetate is derived from blood acetate or from catabolism of glucose and is activated to acetyl-CoA by the action of acetyl-CoA synthetase and then converted to malonyl-CoA via the action of acetyl-CoA carboxylase (Moore and Christie, 1978). Acetyl-CoA carboxylase requires biotin to function. While this pathway is the primary source of carbons for synthesis of fatty acids, there also appears to be a nonbiotin pathway for synthesis of fatty acids C4, C6, and C8 in ruminant mammary-tissue (Kumar et al. 1965 McCarthy and Smith 1972). This nonmalonyl pathway for short chain fatty acid synthesis may be a reversal of the /3-oxidation pathway (Lin and Kumar 1972). 

The energy of the butyryl-CoA linkage and of one of the acetyl-CoA linkages is conserved and utilized in the initial formation of crotonyl-CoA (Eq. 17-32). That leaves one acetyl-CoA which can be converted via acetyl-P to acetate with formation of ATP. 

Cellulose Acetate, Propionate, and Butyrate. Cellulose acetate is prepared by hydrolyzing the triester to remove some of the acetyl groups the plastic-grade resin contains 38-40% acetyl. The propionate and butyrate esters are made by substituting propionic acid and its anhydride (or butyric acid and its anhydride) for some of the acetic acid and acetic anhydride. Plastic grades of cellulose-acetate-propionate resin contain 39-47% propionyl and 2-9% acetyl cellulose-acetate-butyrate resins contain 26-39% butyryl and 12-15% acetyl. 

Acylcobalt carbonyls formed from acyl halides appear to isomerize less readily. No isomerization was found using isobutyryl bromide or n-butyryl chloride in nonpolar solvents such as hexane or benzene. Some isomerization was found with diethyl ether and ethyl acetate as solvents, again promoted by absence of carbon monoxide. Curiously, no isomerization... 

Step B Preparation of 2,3-Dichloro-4-[2-(Dimethylaminomethyl) Butyryl]Phenoxyacetic Acid Hydrochloride - In a 100 ml round flask equipped with an outlet tube suitable for application of intermittent suction, an intimate mixture of 5.20 grams (0.0179 mol) 2,3-dichloro-4-butyrylphenoxyacetic acid 0.63 gram (0.0209 mol) paraformaldehyde 1.59 grams (0.0195 mol) dry dimethylamine hydrochloride and 4 drops acetic acid is heated on the steam... 

Ethoxyphenyl Tellurium Trichloride3 To a vigorously boiling suspension of 9.0 g (30 mmol) 4-ethoxybeiizcne tellurinyl chloride in 50 ml anhydrous carbon tetrachloride is added a solution of 6.4 g (60 mmol) butyryl chloride in 5 ml carbon tetrachloride. The refluxing mixture is stirred for 1 h. On cooling, 4-ethoxypheny] tellurium trichloride precipitates. The precipitate is collected by filtration and recrystallized from acetic acid. The filtrate is stripped of the solvent and the residue distilled at atmospheric pressure. Butyric anhydride boiled at 198° yield 89%. 

Chitosan is insoluble in water, concentrated acids, alkalis, alcohol, and acetone, but dissolves readily in dilute acids. Water-soluble salts of chitosan include the nitrate and the perchlorate. As described on p. 377, formation of chitosan sulfate and the color reaction of chitosan with iodine have been widely used as qualitative tests for the detection of chitin. Nitration of chitosan with a mixture of acetic and nitric acids or with absolute nitric acid enabled both the free ester and its nitrate salt to be isolated. The perchlorate salt of this ester was also prepared, but it was unstable. Chitosan can be W-acetylated to give products similar to chitin except for their greatly reduced chain-length W-formyl-, iV-propionyl-, JV-butyryl-, and iV-benzoyl-chitosan were also prepared. ... 

Butyl peroxylri methyl acetate, see Butyl peroxypivalate Butyl vinyl ether n-Butyraldehyde iso-Butyraldehyde n-Butyric acid iso-Butyric acid n-Butyric anhydride 2-Butyrolactone n-Butyronitrile Butyryl chloride Camphor Caproic acid... 

The initial step in the metabolism of short-chain fatty acids, w hether In cells of the gut lining or in the liver, is conversion to the coenzyine A derivative. For example, acetate is converted to acetyl coeuzyme A (acetyl CoA). The acetyl Co A formed in the cytoplasm can be used for the synthesis of fatly acids, w hereas that formed In the mitochondria can be used for immediate oxidation. Propioriyl CoA can be metabolized as shown in Figure8.7 in Chapter 8. Butyric acid can enter the mitochondria for conversion to butyryl CoA and oxidation in the pathway of fatty acid oxidation. 

This intermediate is subsequently reduced to butyryl-CoA, and the C4 acid is finally formed by reaction with acetate ... 

Acetyl-CoA is regenerated in this process. The overall product yields in moles per mole of glucose converted are approximately 0.5 acetate, 0.75 butyrate, 2 CO2, and 2 H2 2.5 mol ATP are formed. The nonacidic compounds, acetone, 1-butanol, and 2-propanol, are formed by transformation of some of the acetoacetyl-CoA into acetoacetic acid, which is the precursor of acetone and 2-propanol. Some of the butyryl-CoA is the precursor of 1-butanol via intermediate butyraldehyde. Ethanol is formed by reduction of small amounts of acetyl-CoA. The end result of the production of the neutral products by these additional pathways is that the yields of the other products are reduced. The neutral products are in a lower oxidation state than the acidic products and require additional reducing power as NADH to be formed. Some of the product Hj serves to sustain and provide NADH because higher partial pressures of H2 during the fermentation promote higher yields of the neutral products, whereas removal of the product H2 as it is formed has the opposite effect. 

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