Production ethyl valerate

The volatile compounds quantified were acetaldehyde, ethyl acetate, methanol, 1-propanol, isobutanol, amyl alcohols, isobutanol, ethyl valerate, ethyl lactate, ethyl caprylate, ethyl caproate, 2-furfuraldehyde and 2-phenyl ethanol (figure 3). Two yeasts isolated from fermentation stage in the mezcal processes were used to evaluate the volatile production in different agave juice species (table 5 and table 6). Both yeasts are Kluyoeromyces marxianus and the volatile compoxmds were produced at different levels, those results show the importance to select the yeast used in the process. 

In addition, it has been shown that nucleophilic substitution reactions of mPEG-alk-oxides with ethyl 5-bromovalerate and ethyl 4-bromo-4-methyl butyrate, yield mPEG-ethyl valerate and mPEG-ethyl 2-methyl butyrate respectively, which upon hydrolysis should afford the corresponding free acids [81,82]. Presumably these reactions also give elimination products, as indicated for ethyl 3-bromopropionate. 

After further working up there is obtained an oily crystalline residue which is subjected to chromatography on silica gel. The 16a-methyl-6a,9a-difluoro-A -pregnadien-11/3,21-diol-3,20-dione is eluated with ethyl acetatereacted with valeric acid chloride to give the valerate ester. 

Later investigators alcoholyzed imidate salts of other monobasic acids to obtain ortho esters of acetic [13, 14], propionic [15], butyric, valeric, caproic, isocaproic, benzoic [16], and phenylacetic acids [17]. For the latter alcoholysis reactions, the reaction time varies from a few days for the production of methyl orthopropionate to six weeks for ethyl orthobenzoate. McElvain reported that the reaction time is drastically cut by carrying out the reaction in boiling ether [18] or petroleum ether [19]. These conditions provide a reaction temperature below the decomposition point of the imidate salt to the amide. 

It was shown very early by Haller and Bauer7 7 1 that the moot satisfactory halogen in this reaction is chlorine, with bromine and iodine following in that order. When ieebutyrophenone was condensed with ctbyl-[Pg.373]

Other acids (often as esters) have been found in fermented molasses. Usually these substances are products of bacteriological action and they are not normal constituents of unfermented molasses. Bauer" oil from the yeast fermentation of Cuban blackstrap consists chiefly of the ethyl esters of capric, lauric, myristic and palmitic acids.122 The fat from the scums of hot-room Louisiana molasses contained hexanoic (caproic) and octanoic (caprylic) acids.10 The occurrence of such volatile acids as propionic,128 butyric128 124 and valeric acids124 requires more adequate establishment. 

A suspension of 300 mg of adriamycin-14-valerate hydrochloride in 20 ml of ethyl acetate was treated with 0.45 ml of trifluoroacetic anhydride in small portions over a few minutes until all solids had dissolved. The solution was mixed immediately with equal portions of water and chloroform (total volume 100 ml). The chloroform layer was separated and washed once with water and twice with pH 7 aqueous buffer. The chloroform solution was dried over sodium sulfate and then was evaporated to dryness under reduced pressure. The residue was dissolved in 25 ml of methanol, and the resulting solution was heated at reflux for 5 minutes, then cooled and evaporated to dryness. The residue was redissolved in 4 ml of chloroform, and the crude product was precipitated by the addition of 20 ml of petroleum ether (b.p. 38°-49°C). The crude material was purified by chromatography on a silicic acid column. 

A comparable sequence starting from 2,5-dimethylthiophene (Scheme 32) [52] utilised ethyl glutaryl chloride, hydrolysis of the first product giving 5-(2,5-dimethylthien-3-yl)valeric acid which in turn was converted into cyclohepta [c]thiophene 30 by cyclisation using polyphosphoric acid. The bicyclic ketone was used to make a series of l//-pyrazolo[3,4-c]cyclophepta[l,2-c]thiophenes, being a unique structural class of dopamine D4-selective ligands (Scheme 32) [52]. 

Isoamyl nitrite followed by a soln. of Na in ethanol cooled to —15 added at this temp, to ethyl a-carbethoxy-(3-cyanovalerate, the crude product isolated when the mixture has turned brown, dissolved in methanol, acidified with 20%-acetic acid, and treated with 3.5%-Na-amalgam ethyl a-amino-5-cyano-valerate. Y 84%. F. e. s. J. Hannart and A. Bruylants, Bl. Soc. chim. Belg. 72, 423 (1963). 

The linear-to-branched regioselectivity on the hydroxycarbonylation of 1-phenyl-ethanol promoted by Pd(OAc)2 TsOH system (Scheme 6.5) is significantly affected by the nature of the IL media. In both BMI Br and N Bu4- Br, the add product is formed in good yields (86 and 81%, respectively). Interestingly, the selectivity to branched acid was higher in NBu4 Br medium (1 2 = 1.1) than in BMI Br (1 2 =0.4) [64]. A similar catalytic system was employed for the hydroesterification of t-butyl alcohol with ethanol [65]. Because of the immisdbility of IL-ethyl t-valerate, a biphasic system is obtained, such that and the reaction products can easily be separated from the reaction mbcture. 

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