A-methyl butyl acetate

Synonyms a-Methyl butyl acetate 2-pentyl acetate banana oil... 

A professional description of flavours uses as precise descriptors as possible. Chemical analytical results are combined with sensory analysis of the identified components to assess the relative importance and contribution to the flavour profile. Key ingredients or character impact compounds (CIC) are important components sine qua non to impart the typical, product characteristic, flavour, e.g. anethol for anise, eugenol for clove, 3-methyl butyl acetate for banana or ethyl butyrate to improve the juiciness of orange juice. 

CIC 3-methyl butyl acetate represents the fresh, estery, fruity-sweet character reminiscent of technical solvents. Eugenol is responsible for the spicy part of ripe and overripe bananas. A series of volatile esters (3-methyl butyl butyrate, 3-methyl butyl-3-methyl butyrate, 4-hepten-2-yl acetate) round off the general fruity note and vanillin adds the sweet, creamy part. 

Amyl acetate (uo-amyl acetate, 3-methyl-butyl acetate). A colourless liquid with a pleasant, characteristic odour. It has a density of 0.87 gcm. ... 

Thinner A acetone/butyl acetate/methyl Cellosolve acetate (30/50/20) Thinner B butyl acetate... 

Esters of medium volatility are capable of removing the water formed by distillation. Examples are propyl, butyl, and amyl formates, ethyl, propyl, butyl, and amyl acetates, and the methyl and ethyl esters of propionic, butyric, and valeric acids. In some cases, ternary azeotropic mixtures of alcohol, ester, and water are formed. This group is capable of further subdivision with ethyl acetate, all of the ester is removed as a vapor mixture with alcohol and part of the water, while the balance of the water accumulates in the system. With butyl acetate, on the other hand, all of the water formed is removed overhead with part of the ester and alcohol, and the balance of the ester accumulates as a high boiler in the system. 

Ethanol can also be obtained by the reaction of methanol with synthesis gas at 185°C and under pressure (6.9—20.7 MPa or 68—204 atm) in the presence of a cobalt octacarbonyl catalyst (177). However, although ethanol was the primary product, methyl formate, methyl, propyl and butyl acetates, propyl and butyl alcohols, and methane were all present in the product. 

The Claisen condensation of t-butyl acetate with a methyl ester is a general route for the preparation of complex P-ketoesters.4 The reaction requires an excess of the enolate of t-butyl acetate to rapidly deprotonate the product and prevent tertiary alcohol formation. Some workers have also used excess LDA or t-butoxide for this purpose. 

The enantiomeric excess (ee) of the hydrogenated products was determined either by polarimetry, GLC equipped with a chiral column or H-NMR with a chiral shift reagent. Methyl lactate and methyl 3-hydroxybutanoate, obtained from 1 and 2, respectively, were analized polarimetry using a Perkin-Elmer 243B instrument. The reference values of [a]o(neat) were +8.4° for (R)-methyl pyruvate and -22.95° for methyl 3-hydroxybutcinoate. Before GLC analysis, i-butyl 5-hydroxyhexanoate, methyl 5-hydroxyhexanoate, and n-butyl 5-hydroxyhexanoate, obtained from 1, 5, and 6, respectively, were converted to the pentanoyl esters, methyl 3-hydroxybutanoate was converted to the acetyl ester, and methyl 4-methyl-3-hydroxybutanoate obtained from 2 was converted the ester of (+)-a-methyl-a-(trifluoromethyl)phenyl acetic acid (MTPA). 

Addition reactions such as A-alkylation do not occur readily, and trimethylsilylmethylation of 3,4-diphenyl-l,2,5-thiadiazole 8 with trimethylsilylmethyl trifluoromethanesulfonate at 80°C occurred at N-2 < 1999J(P1) 1709>. The electron-rich 3-hydroxy-l,2,5-thiadiazole can be preferentially methylated on N-2 using trimethyl orthoacetate in toluene to afford the 2-methyl-l,2,5-thiadiazol-3-one in 69% yield <2002EJ01763>, although a mixture of 3-hydroxythiadiazole and neat trimethyl orthoacetate showed a 20 80 ratio of N- versus 0-alkylation products by H NMR. Treatment of 3-hydroxy-l,2,5-thiadiazole with /-butyl acetate under acid catalysis (Amberlyst 15) gave almost exclusively the A-alkylated compound <2002BMC2259>. 

A typical elution profile the separation of saturated esters by gas-liquid chromatography 1. methyl formate 2. methyl acetate 3. ethyl formate 4. ethyl acetate 5. -propyl formate 6. iso-propyl acetate 7. w-butyl formate 8. sec-butyl acetate 9. iso-butyl acetate 10. n-butyl acetate... 

Initially, a reaction of A-acetoxy-A-butoxybenzamide 25c with A-methyl aniline 61 in butyl benzoate 63(R = Bu) and acetic acid. Close examination of these highly coloured reaction mixtures indicated the presence of crystals of A,A-dimethyl-A,A-diphenyltetrazene 65 (Scheme 11, R = Bu). The reaction is promoted by polar solvents as reactants are unchanged in pure acetonitrile. A crossover experiment using a mixture of /V- a ce t o x y - A-- b u t o x y - to 1 u a m i d e 26d and A-acetoxy-A-ethoxybenz-amide 25a afforded clean yields of butyl /Moluatc and ethyl benzoate thus pointing to an intramolecular rearrangement.41... 

A variety of other carbon nucleophiles have been alkylated with alcohols including malonate esters, nitroaUcanes, ketonitriles [119, 120], barbituric acid [121], cyanoesters [122], arylacetonitriles [123], 4-hydroxycoumarins [124], oxi-ndoles [125], methylpyrimidines [126], indoles [127], and esters [128]. Selected examples are given in Scheme 35. Thus, benzyl alcohol 15 could be alkylated with nitroethane 147, 1,3-dimethylbarbituric acid 148, phenylacetonitrile 149, methyl-pyrimidine 150, and even f-butyl acetate 151 to give the corresponding alkylated products 152-156. 

A comparison of the kinetics of alkaline hydrolysis of methyl, isopropyl and butyl acetates in propan-2-ol-water and t-butanol-water has revealed that the observed effects correlate with solvent structure. ... 

This enzyme ]EC 4.2.99.13], also known as lupinic acid synthase, catalyzes the reaction of O-acetyl-L-serine with zeatin to produce lupinate and acetate. Zeatin is N -(4-hydroxy-3-methyl-butyl-iran5 -2-enylamino)purine. A number of other A -substituted purines can function as substrates for this enzyme. 

Chemicals obtained from jjetroleum having four carbons are manufactured at a considerably lower scale than ethylene or propylene derivatives. Only five C4 compounds— butadiene, acetic acid, vinyl acetate, isobutylene, and methyl /-butyl ether (MTBE)— appear in the top 50. The manufacture of butadiene and isobutylene, as well as the separation of other C4 compounds from petroleum, is described in Chapter 8, Sections 3-5. Acetic acid was discussed as a derivative of ethylene in Chapter 9, Section 3 and is discussed as a derivative of methane in Chapter 12, Section 3. Vinyl acetate was discussed in Chapter 9, Section 4. A few important derivatives of C4 chemistiy will be briefly mentioned here as well as MTBE. 

The synthesis of (-t-)-benzoylselenopederic acid (569) (477) (Scheme 71), the left-hand half of pederin (147), began with (-f-)-3-keto imide 570, which was subjected to the recently developed syn-directing Zn(BH4)2 reduction (482) to give 5yn-a-methyl-3-hydroxy acid derivative 571. Imide 571, after protection of the hydroxyl group as the THP ether, was reduced with DIBAH, and the resulting aldehyde was treated with lithium enolate of tm-butyl acetate to give the p-... 

---