Isoamyl aldehyde

Synonyms 1-Butanal, 3-methyl- Isoamyl aldehyde Isopentaldehyde Isovaleral Isovaleric aldehyde 2-Methylbutanal-4 3-Methylbutanal 3-Methylbutyraldehyde... 

Other modifications of the polyamines include limited addition of alkylene oxide to yield the corresponding hydroxyalkyl derivatives (225) and cyanoethylation of DETA or TETA, usuaHy by reaction with acrylonitrile [107-13-1/, to give derivatives providing longer pot Hfe and better wetting of glass (226). Also included are ketimines, made by the reaction of EDA with acetone for example. These derivatives can also be hydrogenated, as in the case of the equimolar adducts of DETA and methyl isobutyl ketone [108-10-1] or methyl isoamyl ketone [110-12-3] (221 or used as is to provide moisture cure performance. Mannich bases prepared from a phenol, formaldehyde and a polyamine are also used, such as the hardener prepared from cresol, DETA, and formaldehyde (228). Other modifications of polyamines for use as epoxy hardeners include reaction with aldehydes (229), epoxidized fatty nitriles (230), aromatic monoisocyanates (231), or propylene sulfide [1072-43-1] (232). 

French oil of peppermint eontains. in addition to menthol and iia, isovaleric aldehyde, isoamyl alcohol, i-pinenc. A -p-monthcne aed... 

Electrophilic substitution of the ring hydrogen atom in 1,3,4-oxadiazoles is uncommon. In contrast, several reactions of electrophiles with C-linked substituents of 1,3,4-oxadiazole have been reported. 2,5-Diaryl-l,3,4-oxadiazoles are bromi-nated and nitrated on aryl substituents. Oxidation of 2,5-ditolyl-l,3,4-oxadiazole afforded the corresponding dialdehydes or dicarboxylic acids. 2-Methyl-5-phenyl-l,3,4-oxadiazole treated with butyllithium and then with isoamyl nitrite yielded the oxime of 5-phenyl-l,3,4-oxadiazol-2-carbaldehyde. 2-Chloromethyl-5-phenyl-l,3,4-oxadiazole under the action of sulfur and methyl iodide followed by amines affords the respective thioamides. 2-Chloromethyl-5-methyl-l,3,4-oxadia-zole and triethyl phosphite gave a product, which underwent a Wittig reation with aromatic aldehydes to form alkenes. Alkyl l,3,4-oxadiazole-2-carboxylates undergo typical reactions with ammonia, amines, and hydrazines to afford amides or hydrazides. It has been shown that 5-amino-l,3,4-oxadiazole-2-carboxylic acids and their esters decarboxylate. 

Condensations of 5-methyl-substituted 1,2,4-thiadiazoles with aromatic aldehydes lead to 5-styrylthiadiazoles. With carboxylic acid esters, ethoxalyl derivatives are formed, and isoamyl nitrite produces the corresponding oximes <1982AHC285>. These reactions are restricted exclusively to the 5-methyl-substituted 1,2,4-thiadiazoles reflecting the greater reactivity of substituents in the 5-position compared to the 3-position in 1,2,4-thiadiazoles. 

Cyclohexane Methylcyclohexane Phenol Terpenes Turpentine Alcohols Methyl alcohol Ethyl alcohol 2-propen-l-ol n-Propyl alcohol Isopropyl alcohol n-Butyl alcohol Amyl alcohol Isoamyl alcohol Aldehydes Formaldehyde Acetaldehyde Acrolein... 

Condensation of the 5-methyl group in (80) (R = Me, Et, Ph, SMe) with aromatic aldehydes leads to 5-styrylthiadiazoles (79). The action of carboxylic acid esters gives ethoxalyl derivatives (81) and that of isoamyl nitrite produces the oxime (82) (Scheme 20) <82AHC(32)285>. These reactions are restricted exclusively to the 5-methyl group in (80) (R = Me), reflecting the greater reactivity of substituents in the 5-position compared to the 3-position in 1,2,4-thiadiazoles. This point is further illustrated when (80) (R = Me) is selectively converted into the carboxylic acid (83) on treatment with n-butyllithium and carbon dioxide (Scheme 20) <84CHEC-I(6)463). 

Higher Alcohols. The most abundant, volatile minor products of alcoholic fermentation are the higher alcohols or fusel alcohols. The most important are isoamyl (3-methyl-l-butanol), d-active amyl (2-methyl-l-butanol), isobutyl (2-methy 1-1-propanol), and n-propyl (1-propanol) alcohols. It is now recognized (4, 5, 6, 7) that these higher alcohols are formed by decarboxylation of particular a-keto acids to yield the corresponding aldehydes, and these in turn are reduced to the alcohols in a manner analogous to the formation of ethyl alcohol from pyruvic acid. 

Saturated aldehyde (isovaleraldehyde), unsaturated and saturated alcohols (prenol and isoamylic alcohol) simultaneously appear at the initial stage of the reaction prenol is the majoritary product of the reaction but it rapidly undergoes a second hydrogenation. 

The dehydrogenation of alcohols was first studied by Ipatieff, who obtained the corresponding aldehydes or ketones by treatment of methyl, ethyl, isopropyl, isobutyl, and isoamyl alcohols with such catalysts as a platinum tube, zinc rods, and brass at suitable temperatures. The work of Sabatier and Senderens and later Constable and Palmer added to the understanding of this industrially important reaction. 

Isoamyl Alcohol. — The amyl alcohol produced during fermentation was likewise exposed by Elbs and Brunner to the anodic current action in sulphuric-acid solution. It is converted into isovaleric acid with a current yield of about 80%. Some carbonic acid also formed, but isovaleric aldehyde was not present under the chosen conditions. 

Hydroboration-Oxidation of Alkynes Hydroboration-oxidation of an alkyne gives anti-Markovnikov addition of water across the triple bond. Di(secondary isoamyl)borane, called disiamylborane, is used, since this bulky borane cannot add twice across the triple bond. On oxidation of the borane, the unstable enol quickly tautomerizes to an aldehyde. (See Section 9-9F.)... 

Brett flavor in wine The question still remains what is "Brett" flavor Results from our initial work indicates that "Brett" aroma in wine is a complex mixture of odor-active compounds, including acids, alcohols, aldehydes, ketones, esters, and phenolics. Analysis by gas chromatography-olfactometry revealed two predominate odor-active compounds responsible for the Brett flavor in the wines studied isovaleric acid and a second unknown compound other identified odor-active compounds included 2-phenyl ethanol, isoamyl alcohol, cis-2-nonenal, trans-2-nonenal, B-damascenone, ethyl decanoate, guaiacol, 4-ethyl guaiacol, 4-ethyl phenol. Our findings are a snapshot into the much larger picture know as Brett flavor. Ultimately this preliminary investigation requires the descriptive analyses of many more wines to know what odor active compounds describe the flavor know as "Brett". 

The vinylogous nitroso-substituted TTF 807 was obtained in the Wittig reaction of the phosphonium salt 800 with the aldehyde 806. The second nitroso group in 807 was introduced by nitrosation using isoamyl nitrite to give 808 (Scheme 122) <1997JOC2616>. 

Figure 3 shows the partial pressure of each product versus time for the hydrogenation of prenal in tlte standard conditions. Throughout the reaction, the fractions of unsaturated alcohol (prenol), saturated aldehyde (Lsovaleraldehyde) and saturated alcohol (isoamylic alcohol) remain small (lower than 5%) the Light products, identified as C4 and C5 hydrocarbons, are by far in majority and more than 15% at the end of the reaction. The C4/C5 ratio is between 1 and 2. It may be added that the selectivity does not vary considerably with conversion. 

The aldehydes and fusel oils recoverd from distillation are also referred to as congeners, or flavor components. Most of the aldehyde content is acetaldehyde, although other aldehydes are also present. The fusel oils (from the German fuselol meaning bad spirits ) are thought to arise via yeast fermentation of amino acids present in the original mash. They include amyl, and isoamyl alcohols (about 50%), n-butanol (about 20%), and a residue of fatty acids and several other higher alcohols [47] (Eq. 16.17). 

The catalytic activity of TPA-PVA-PEG catalyst for the esterification of acetic acid with isoamyl alcohol is presented in Table 1. A high selectivity to the ester was obtained, although traces of 3-methyl-1-butene, 2-methyl-1-butene, and isovaleric aldehyde were... 

Over copper isoamyl alcohol yields the aldehyde at 240° to 300° C. without side reactions. About 6 per cent of the product is decomposed at 390° C. and about 25 per cent at 430° C. 

Fusel Oil and Succinic Acid, etc.—It has been shown that this group of by-products derives not from the sugar but from other materials present in the fermenting liquor. F. Ehrlich in many researches (1904-1910) has shown that the higher alcohols and aldehydes, which when mixed we call fusel oil, are formed by the deammination of amino acids resulting from the hydrolysis of proteins. Thus isoamyl alcohol, which is the chief constituent of fusel oil, is closely related to leucine, amino-isohexoic acid, and active amyl alcohol is similarly related to isoleucine, a-amino-/ -... 

Hollow-fiber MBR have also been used for the production of a number of other fine chemicals. Molinari et al [4.42] used such a MBR for the production of isovaleraldehyde from isoamyl alcohol using Gluconobacter oxidans. In their work hydrophobic hollow-fiber membranes were used in order to continuously extract the aldehyde, thus, avoiding its oxidation to the corresponding acid. Hollow-fiber MBR have also been used by Ko-yama et al [4.27] in the synthesis of L-aspartic acid by E. coli, and by Cantarella et al... 

Isovaleraldehyde. 3-Mcthylbutanal isovaleral isovaleric aldehyde. CjH.,0 mol wt 86.13. C 69.72%, H 11.70%, O 18.58%, (CHjXCHCHjCHO Occurs in orange, lemon, peppermint, eucalyptus and other oils. Made by oxidation of isoamyl alcohol with Htt1Cr101 and IIjSO,... 

Esters aldehydes, ketones aromatic hydrocarbons chloroform ethers acids bases Higher alcohols (e.g., isoamyl and isopropyl alcohol) esters ethers strong acids and bases aliphatic and aromatic hydrocarbons chlorinated solvents Ketones methyl alcohol dioxane ethers aldehydes tetrahydrofuran... 

---