Crotonaldehyde oxidation

Normal butyl alcohol, propyl carbinol, n-butanol, 1-buianol, CH3CH2CH2CH2OH. B.p. 117 C. Manufactured by reduction of crotonaldehyde (2-buienal) with H2 and a metallic catalyst. Forms esters with acids and is oxidized first to butanal and then to butanoic acid. U.S. production 1978 300 000 tonnes. 

Acetaldehyde (and other aldehydes containing at least one hydrogen atom in the a position) when treated with a small quantity of dilute sodium hydr oxide solution or other basic catalyst gives a good yield of aldol (p hydroxy-n-but3Taldehyde) (I), which readily loses water, either by heating the isolated aldol alone or with a trace of mineral acid, to form crotonaldehyde (II) ... 

The commercial method consists in the oxidation of crotonaldehyde, which is itself prepared from acetaldehyde (see Section 111,141) ... 

Most commercial sorbic acid is produced by a modification of this route. Catalysts composed of metals (2inc, cadmium, nickel, copper, manganese, and cobalt), metal oxides, or carboxylate salts of bivalent transition metals (2inc isovalerate) produce a condensation adduct with ketene and crotonaldehyde (22—24), which has been identified as (5). 

Union Carbide abandoned the ketene—crotonaldehyde route in 1953 in favor of the oxidation of 2,4-hexadienal made by acetaldehyde condensation. A silver compound used as the catalyst prevented peroxidation of the ethylenic bonds (39,40). Thein plant operated until 1970. 

Preparing sorbic acid by reaction of crotonaldehyde and acetone followed by oxidation of the crotonyUdenacetone is of interest in the former Soviet Union (41,42) ... 

The bicyclic nature of the labile adduct (79) from 3-methyl-pyridine was established by Acheson and Taylor who found that hydrogenation, yielding (80), followed by oxidation gave pyridine-3,4,5-tricarboxylic acid. This conclusion is consistent with Diels and Alder s observations that acid hydrolysis of the labile pyridine adduct gave pyridine and some crotonaldehyde, whereas alkaline hy-... 

In some parts of the world, as in Russia, fermented alcohol can serve as a cheap source for hutadiene. The reaction occurs in the vapor phase under normal or reduced pressures over a zinc oxide/alumina or magnesia catalyst promoted with chromium or cohalt. Acetaldehyde has been suggested as an intermediate two moles of acetaldehyde condense and form crotonaldehyde, which reacts with ethyl alcohol to give butadiene and acetaldehyde. 

It is often said that the property of acidity is manifest only in the presence of a base, and NMR studies of probe molecules became common following studies of amines by Ellis [4] and Maciel [5, 6] and phosphines by Lunsford [7] in the early to mid 80s. More recently, the maturation of variable temperature MAS NMR has permitted the study of reactive probe molecules which are revealing not only in themselves but also in the intermediates and products that they form on the solid acid. We carried out detailed studies of aldol reactions in zeolites beginning with the early 1993 report of the synthesis of crotonaldehyde from acetaldehyde in HZSM-5 [8] and continuing through investigations of acetone, cyclopentanone [9] and propanal [10], The formation of mesityl oxide 1, from dimerization and dehydration of... 

Sorbic acid has been prepared from crotonaldehyde 1 5 or aldol6 and malonic acid in pyridine solution by hydrogen peroxide oxidation of the condensation product of crotonaldehyde and pyruvic acid 7 and by the action of alkali on 3-hydroxy-4-hexenoic acid,8 9 /3,5-disulfo-w-caproic acid,10 and parasorbic acid.1112... 

Creosol, 33, 17 Crotonaldehyde, 33, IS 34, 29 diethyl acetal, 32, 5 Cupric acetate monohydrate, 36, 77 Cuprous oxide-silver oxide, 36, 36, 37 Cyanamide, 34, 67 36, 8 Cyanoacetamide, 32, 34 Cyanoacetic acid, 31, 25 Cyanoacetylurea, 37, 16 >-Cyanobenzaldehyde, 30, 100 >-Cyanobenzaldiacetate, 36, 59 3-Cyano-5,6-dimethyl-2(l)-pyridone, 32,34 N-2-Cyanoethylaniline, 36, 6 N-2-Cyanoethyl- -anisidine, 36, 7 Cyanoethylation, of aniline, 36, 6 of ethyl phenylcyanoacetate, 30, 80 N-2-Cyanoethyl-m-chloroaniline, 36, 7 Cyanogen, 32, 31 Cyanogen iodide, 32, 29 Cyanogen iodide, complex with sodium iodide, 32, 31... 

Chemical/Physical. Slowly oxidizes in air forming crotonic acid (Windholz et al., 1983). At elevated temperatures, crotonaldehyde may polymerize (NIOSH, 1997). 

Propylbenzene, see Propylbenzene Propyl carbinol, see 1-Butanol Propylene aldehyde, see Acrolein, Crotonaldehyde Propylene chloride, see 1,2-Dichloropropane Propylene dichloride, see 1,2-Dichloropropane a,p-Propylene dichloride, see 1.2-Dichloropropane 1,2-Propylene oxide, see Propylene oxide Propyl ester of acetic acid, see Propyl acetate Propylethylene, see 1-Pentene 5-Propylhexane, see 4-Methyloctane Propyl hydride, see Propane Propylic alcohol, see 1-Propanol Propyl iodide, see 1-Iodopropane n-Propyl iodide, see 1-Iodopropane Propylmethanol, see 1-Butanol Propyl methyl ketone, see 2-Pentanone n-Propyl nitrate, see Propyl nitrate... 

Maleic anhydride (2,5-furandione) is obtained as a by-product in the production of phthalic anhydride and by the vapor phase oxidation of butylene or crotonaldehyde. It is also obtained by the dehydration of maleic acid and by the oxidation of benzene. Maleic anhydride is used for the production of unsaturated polyester resin. This reactant, like most reactants, is fairly toxic and should be treated as such. 

The same authors (77) also investigated the Michael addition of nitromethane to a,/l-unsaturated carbonyl compounds such as methyl crotonate, 3-buten-2-one, 2-cyclohexen-l-one, and crotonaldehyde in the presence of various solid base catalysts (alumina-supported potassium fluoride and hydroxide, alkaline earth metal oxides, and lanthanum oxide). The reactions were carried out at 273 or 323 K the results show that SrO, BaO, and La203 exhibited practically no activity for any Michael additions, whereas MgO and CaO exhibited no activity for the reaction of methyl crotonate and 3-buten-2-one, but low activities for 2-cyclohexen-l-one and crotonaldehyde. The most active catalysts were KF/alumina and KOH/alumina for all of the Michael additions tested. 

Very recently, ammonium peroxydisulfate mediated oxidative hydrolysis of a cyclic l,Af -propauo-2 -deoxyguauosiue was also reported by the same research group. The formation of the guanine ring-opened products in this oxidation reaction seems very interesting and appears to be closely related to the mechanism for the point-mutations of DNA with excessive acetaldehyde and crotonaldehyde. 

There are some cases where both types of photocycloaddition take place. For example, cinnamaldehyde and crotonaldehyde yield, upon irradiation with 2-methyl-2-butene, both the oxetane and the cyclobutane products.26 In marked contrast, mesityl oxide, as similar as it would appear to be to crotonaldehyde (Table I), is stable to irradiation in the presence of both isobutylene and isopropanol.37,74 These differences in reactivity of a,/9-unsaturated carbonyl compounds have been attributed to conformational (that is, s-cis or s-trans) differences.74... 

Among the aldehydes and ketones tested acetone was least toxic, formaldehyde, butyraldehyde, and crotonaldehyde next, and mesityl oxide most toxic. In this group of compounds temperature was a major factor, both formaldehyde and mesityl oxide being much more toxic at 40 than at 25 C. None were outstanding as cholesterol solvents, but mesityl oxide was the best it penetrated nematodes the most easily and killed in the lowest concentrations. 

For example, crotonaldehyde is listed in Table 1 as belonging in Group 19 (Aldehydes). The Chart shows that chemicals in this group should be segregated from sulfuric and nitric acids, caustics, ammonia, and all types of amines (aliphatic, alkanol, and aromatic). According to note A, crotonaldehyde is also incompatible with non-oxidizing mineral acids. 

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