Decanoates

Barnes and co-workers have studied mixed-monolayer systems [278,281,283,284] and found some striking nonidealities. Mixed films of octadecanol and cholesterol, for example, show little evaporation resistance if only 10% cholesterol is present [278] apparently due to an uneven granular microstructure in films with cholesterol [284]. Another study of cellulose decanoate films showed no correlation between holes in the monolayer and permeation rate [285]. Polymerized surfactants make relatively poor water evaporation retarders when compared to octadecanol [286]. There are problems in obtaining reproducible values for r [287] due to impurities in the monolayer material or in the spreading solvent. 

The first molecular dynamics simulations of a lipid bilayer which used an explicit representation of all the molecules was performed by van der Ploeg and Berendsen in 1982 [van dei Ploeg and Berendsen 1982]. Their simulation contained 32 decanoate molecules arranged in two layers of sixteen molecules each. Periodic boundary conditions were employed and a xmited atom force potential was used to model the interactions. The head groups were restrained using a harmonic potential of the form ... 

By increasing the molar proportion of the monocarboxylic acid, the yield of (II) is improved. Thus electrolysis of a mixture of decanoic acid (n-decoic acid capric acid) (V) (2 mols) and methyl hydrogen adipate (VI) (1 mol) in anhydrous methanol in the presence of a little sodium methoxide gives, after hydrolysis of the esters formed, n-octadecane (VII), tetradecanoic or myristic acid (VIH) and sebacic acid (IX) ... 

Under CO pressure in alcohol, the reaction of alkenes and CCI4 proceeds to give branched esters. No carbonylation of CCI4 itself to give triichloroacetate under similar conditions is observed. The ester formation is e.xplained by a free radical mechanism. The carbonylation of l-octene and CCI4 in ethanol affords ethyl 2-(2,2,2-trichloroethyl)decanoate (924) as a main product and the simple addition product 925(774]. ... 

Cd(C24H2g02)2, are of this type. Liquid stabilizers such as cadmium octoate [2191 -10-8] Cd(CgH2g02)2, cadmium phenolate [18991 -05A] Cd(CgHgO)2, cadmium decanoate [2847-16-7] Cd(C2QH2Q02)2, cadmium benzoate [3026-22-0] and cadmium naphthenate are more versatile and... 

Capric acid (decanoic acid) [334-48-5] M 172.3, m 31.5 , b 148 /llmm, d 0.886, n s 1.424, pKesi -4.9. Purified by conversion to its methyl ester, b 114.0 /15mm (using excess MeOH, in the presence of H2SO4). After removal of the H2SO4 and excess MeOH, the ester was distd under vacuum through a 3ft... 

Sodium decanoate (sodium caproate) [1002-62-6] M 194.2. Neutralised by adding a slight excess of the free acid, recovering the excess acid by Et20 extraction. The salt is crystd from solution by adding pure acetone, repeating the steps several times, then dried in an oven at ca 110° [Chaudhury and Awuwallia Trans Faraday Soc 77 3119 1981]. 

Sodium dodecanoate (sodium laurate) [629-25-4] M 222.3, pK 5.3 (-COOH). Neutralised by adding a slight excess of dodecanoic acid, removing it by ether extraction. The salt is recrystd from aq soln by adding pure Me2CO and repeating the process (see sodium decanoate on p. 468). Also recrystd from MeOH. 

Phytanic acid, the product of chlorophyll that causes problems for individuals with Refsum s disease, is 3,7,11,15-tetramethyl hexa-decanoic acid. Suggest a route for its oxidation that is consistent with what you have learned in this chapter. Hint The methyl group at C-3 effectively blocks hydroxylation and normal /3-oxidation. You may wish to initiate breakdown in some other way.)... 

Oil-soluble derivatives of testosterone itself predate those of its 19-nor congener these agents too are used to administer depot injections so as to provide in effect long-term blood levels of drug. Thus, acylation of testosterone with propionyl chloride in the presence of pyridine yields testosterone propionate (76a)acylation by means of decanoic anhydride yields testosterone decanoate (76b).Finally, reaction of 75 with 3-cyclopentylpropionyl chloride affords testosterone cypionate (76c)This last undergoes hydrolysis unusually slowly because of the presence of two substituents at the 5 position (see Newman s Rule of 6). ... 

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