Ester natural

M Bodanszky. Synthesis of peptides by aminolysis of nitrophenyl esters. Nature (London) 75, 685, 1955. 

The ds-hydrogenation of cyclopropenes is unexceptional in itself but when preceded by the addition of diazopropane to the yne component of an enyne (Section II.B) it provides a stereospecific synthesis of chrysanthemic acid esters (natural pesticides) in high yield. Reduction of unsymmetrical cyclopropenes with lithium aluminium... 

Ketelaar, J.A.A., Gersmann, H.R., and Beck, M.M. 1956. Metal-catalyzed hydrolysis of thiophosphoric esters. Nature, 111 392-393. 

Ageflex FM-68 Ageflex FM-1620 A13-25418 EINECS 251-013-5 Methacrylio acid, octadecyi ester Methacrylic acid, stearyl ester Octadecyl methacrylate 2-Propenoic acid, 2-methyl-, octadecyl ester. Natural, C16-I8 methacrylates, with 100 ppm hydroquinone inhibitor lube oil additive, pour point depressant, paper coatings, textile finishes, paints, varnishes, pressure-sensitive adhesives. Lube oil additive, pour point depressant. Used in paper coatings, textile finishes, paints, varnishes, pressure-sensitive adhesives. Liquid bps = 181° d 8 = 0.868 f.p. -20° flash pt. 110°. Rit-Chem Rohm Haas Co. Sartomer. 

The results obtained with the anhydrolupinines and lupinanes indicated that there were two asymmetric centers in the lupinine molecule. The same conclusion was reached in studies on the isomerization of lupininic acid (XXIV) esters. Natural lupinine is levorotatory. Methyl lupininate (XXV) made by Schopf and Thoma (121) according to the directions of Willstatter and Fourneau (118) was obtained which varied from [a]n — 19.4° to -f 5.8° (methanol) in different batches. The most levorotatory sample of ester, methyl ( —)lupininate, formed a noncrystalline picrate, the rotation of which was useful for identification... 

Summary of the preparation of keto-esters Natural reactivity and umpolung 719... 

Although the liver is the body s principal centre for metabolic degradation, this process also goes on elsewhere. For example the bloodstream carries non-specific esterases which rapidly hydrolyse almost every kind of ester, natural or fabricated, and they are accompanied by a rather less active nonspecific amidase. Many degradative enzymes operate in the bowel-wall and the kidney. An inactivator of catecholamines, catechol 0-methyltransferase, is found in many tissues, and Section 12.5 describes the enzyme that hydrolyses acetylcholine in the neuromuscular junction. 

Chem. Deserp. Partially polymerized (dimerized) rosin CAS 8050-09-7 EINECS/ELINCS 232-475-7 Uses Prep, of varnishes, driers, syn. resins, ink vehicles, floor tile, rubber compds., solder fluxes, elec, insulation oils, optical lens pilches, adhesives and protective coatings for food pkg./processing Features Noncrystallizing, high soften, pi., acidic resin Properties Gardner 8 (60% solids in min. spirits) solid, flakes sol. in aliphatic, aromatic, and chlorinated hydrocarbons, in ketones, esters, natural oils, terpenes, and varnish oils dens. 1.07 kg/l G-H vise. C (60% solids in min. spirits) Hercules drop soften, pt. 102 C flash pt. (COC) 218 C acid no. 144 sapon. no. 160 Polyplate 90 [Huber Engineered Materials]... 

Polyamides. Polyamide resins are characterized by the presence of the repeating amide group along the polymer chain -C(=0)-NH-. The polyamides are synthesized by the condensation polymerization of diamino compounds with dicarboxylic acids or esters. Naturally occurring fatty acids such as linoleic acid, or their derivatives, are often reacted with diamines to yield a series of liquid resins. Polyamides are thermoplastics used primarily as hot-melt adhesives that bond well to porous surfaces and have excellent flexibility at low temperatures. 

Swann K, Whitaker M. 1985. Stimulation of the Na/H exchanger of sea urchin eggs by phorbol ester. Nature 314(6008) 274-277. 

Why are thioesters superior to ordinary esters as acyl-transfer agents Part of the answer lies in the acidity difference between alcohols and thiols (Sec. 7.1 7). Since thiols are much stronger acids than are alcohols, their conjugate bases, SR, are much weaker bases than OR. Thus, the —SR group of thioesters is a much better leaving group, in nucleophilic substitution reactions, than is the —OR group of ordinary esters. Thioesters are not so reactive that they hydrolyze in cellular fluid, but they are appreciably more reactive than simple esters. Nature makes use of this feature. 

The palm oil methyl ester (MEl) and its blends with DF have shown poor cold flow behavior especially for B30 and this can be explained by the fact that this ester naturally contains more saturated fatty acids (38 %) than, for example, ME2 (7 %). These saturated compounds have higher melting and crystallization points. 

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