Ethyl octanoate, hydrolysis

Ester formation is associated with yeast growth in the early phase of fermentation. Acetate esters are produced via the reaction between an alcohol and acetyl Co-A, which is catalysed by the enzyme alcohol acetyl transferases (ATFl and ATF2). Ethanol, branched-chain alcohols and 2-phenylethanol are the common moieties of acetate esters. Ethyl esters of medium-chain fatty adds are formed through the reaction between ethanol and respective fatty acyl Co-A, which is catalysed by the enzyme alcohol acyl transferases. Saccharomyces cerevisiae strains also produce esterases that hydrolyse esters, and thus the final concentration of esters in beers is the net balance between ester synthesis and hydrolysis. Strains of brewing yeasts produce predominantly ethyl esters of fatty acids, particularly ethyl octanoate, with relatively little formation of acetate esters. Ester production in beer is regulated by a number of factors such as yeast strain, temperature, hydrostatic pressure, wort composition, sugar type and concentration, type and amount of yeast-assimilable nitrogen, aeration, and unsaturated fatty acids (Hiralal, Olaniran, PiUay, 2014 Pires et al., 2014). 

Kinetic studies of the alkaline hydrolysis of dimethyl and diethyl phthalate, ethyl benzoate, benzyl cinnamate, and diethyl malonate at 298-313 K in aqueous dioxane were reported. Activation parameters were determined for the alkaline hydrolysis of ethyl octanoate in various mixtures of PrOH-water."... 

In the Sepracor synthesis of chiral cetirizine di hydrochloride (4), the linear side-chain as bromide 51 was assembled via rhodium octanoate-mediated ether formation from 2-bromoethanol and ethyl diazoacetate (Scheme 8). Condensation of 4-chlorobenzaldehyde with chiral auxiliary (/f)-f-butyl sulfinamide (52) in the presence of Lewis acid, tetraethoxytitanium led to (/f)-sulfinimine 53. Addition of phenyl magnesium bromide to 53 gave nse to a 91 9 mixture of two diastereomers where the major diasteromer 54 was isolated in greater than 65% yield. Mild hydrolysis conditions were applied to remove the chiral auxiliary by exposing 54 to 2 N HCl in methanol to provide (S)-amine 55. Bisalkylation of (S)-amine 55 with dichlonde 56 was followed by subsequent hydrolysis to remove the tosyl amine protecting group to afford (S)-43. Alkylation of (5)-piperizine 43 with bromide 51 produced (S)-cetirizine ethyl ester, which was then hydrolyzed to deliver (S)-cetirizine dihydrochloride, (5)-4. 

Fig. 19- The efficiency, q, of the Amberlite IR-120 ion exchanger catalyst in ester hydrolysis as a function of the entropy, S, of the parent hydrocarbon RH or R H of the substituents, (a) Hydrolysis (at 25—45°C) of methyl esters RCOOCH3 [366] 1, acetate 2, chloroacetate 3, benzoate 4, cyclopentanecarboxylate 5, phenylacetate 6, a-naphthylacetate 7, 1-octanoate. (b) Hydrolysis (at 35°C) of acetates CH3COOR [480] 1, methyl 2, ethyl 3, cyclopentyl 4, cyclohexyl 5, 1-butyl 6, 2-pentyl 7, 1 -pentyl 8, 1 -hexyl 9, 1 -octyl,...

Sucrose was actylated at 0-1 preferentially by subtilisin-catatysed transesterification from the trifluoro- or trichloro- ethyl esters of acetic, propionic, octanoic, benzoic, and acrylic acid in DMF. Subsequent hydrolysis of the yoosidic bond with a-glucosidase gave D-fructose l-esters. ... 

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