Ethyl caprylate

A particularly interesting type of micellar catalysis is the autocatalytic self-replication of micelles [58]. Various examples have been described, but a particularly interesting case is the biphasic self-reproduction of aqueous caprylate micelles [59]. In this system ethyl caprylate undergoes hydroxyl catalysed hydrolysis to produce the free carboxylate anion, caprylate. Caprylate micelles then fonn. As these micelles fonn, they solubilize ethylcaprylate and catalyse further production of caprylate anion and caprylate micelles. 

Ethyl Caprylate.—This ester is an oil reminding one of the secondary products of fermentation. It boils with decomposition at 275° to 290°, and has the formula CH3(CH2) COOC2H5. 

Ethyl a-bromoisobutyrate, 21, 53 Ethyl /3-bromopropionate, 20, 6S Ethyl caprylate, 20, 69 Ethyl carbonate, 23, 95, 97 Ethyl chlorocarbonate, 21, 81 2-Ethylchromone, 21, 42 Ethyl diacetylacetate, 21, 46 copper derivative, 21, 46 Ethyl a,a-DIMETHYL-/3-PHENYL-/3-hydroxypropionate, 21, S3 Ethylene chloride, 20, 28 22, 76 ETHYLENEDIAMINE, IV IV-DIBUTYL-, 23, 23... 

Ethyl butyl ketone, hi5 Ethyl caprate, el20 Ethyl caproate, el60 Ethyl caprylate, e231 Ethyl chloride, cl21... 

This procedure has been used successfully for many years in the preparation of ethyl laurate, caprylate, and myristate by the alcoholysis of cocoanut oil (1 kg.) in ethanol (1900 g.) with hydrogen chloride (50 g.) as a catalyst.3 The method differs slightly from the one described above. The alcoholysis is complete after fifteen or twenty hours, and the solution is then neutralized to methyl orange with barium carbonate. The mixture is added to an equal volume of a saturated sodium chloride solution, whereupon 1100-1300 g. of the mixture of crude ethyl esters separates. This mixture of esters is washed with water and fractionated as described above. The yields are approximately 50 g. of ethyl caprylate, 350 g. of ethyl laurate, and 60 g. of ethyl myristate from 1000 g. of cocoanut oil. 

Let us recall the micellar aqueous system, as this procedure is actually the basic one. The chemistry is based on fatty acids, that build micelles in higher pH ranges and vesicles at pH c. 8.0-8.5 (Hargreaves and Deamer, 1978a). The interest in fatty acids lies also in the fact that they are considered possible candidates for the first prebiotic membranes, as will be seen later on. The experimental apparatus is particularly simple, also a reminder of a possible prebiotic situation the water-insoluble ethyl caprylate is overlaid on an aqueous alkaline solution, so that at the macroscopic interphase there is an hydrolysis reaction that produces caprylate ions. The reaction is very slow, as shown in Figure 7.15, but eventually the critical micelle concentration (cmc) is reached in solution, and thus the first caprylate micelles are formed. Aqueous micelles can actually be seen as lipophylic spherical surfaces, to which the lipophylic ethyl caprylate (EC) avidly binds. The efficient molecular dispersion of EC on the micellar surface speeds up its hydrolysis, (a kind of physical micellar catalysis) and caprylate ions are rapidly formed. This results in the formation of more micelles. However, more micelles determine more binding of the water-insoluble EC, with the formation of more and more micelles a typical autocatalytic behavior. The increase in micelle population was directly monitored by fluorescence quenching techniques, as already used in the case of the... 

Octanol has previously been prepared from ethyl caprylate by catalytic hydrogenolysis,21 and by the Bouveault-Blanc method using sodium and alcohol in toluene.22 Other preparative methods include the reaction between fi-hexylmagnesium... 

Ethyl bromide, b277 Ethyl butyl ether, b449 Ethyl caprylate, el 90 ... 

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