Alkene carboxylic acids from

The telomer obtained from the nitromethane 65 is a good building block for civetonedicarboxylic acid. The nitro group was converted into a ketone, and the terminal alkenes into carboxylic acids. The acyloin condensation of protected dimethyl dvetonedicarboxylate (141) afforded the 17-membered acyloin 142, which was modified to introduce a triple bond 143. Finally, the triple bond was reduced to give civetone (144)[120). 

Table 11.5. Substituted cyclopropanols 31 from carboxylic acid esters and alkenes via ligand-exchanged titanium intermediates generated from Grignard reagents and XTi(OiPr)3 (X = OiPr, Cl, Me).

Non-oxidative hydrocarboxylation of alkenes to carboxylic acids with CO and H20 is catalyzed by palladium complexes such as PdCl2(PhCN)2 or PdCl2(PPh3)2, and a-methyl acids predominate in the presence of HC1.374,443 A recent improvement of this reaction consisted of the use of a PdCl2/CuCl2/HCl catalyst under oxidative conditions.377 Almost quantitative yields of a-methyl carboxylic acids and dicarboxylic acids were obtained from terminal alkenes and terminal dialkenes respectively, at room temperature and atmospheric pressure (equation 174).377... 

Vapor pressure selectivity and other phase-specific reactions might be useful for achieving selectivity not possible by conventional means. The method makes reactive radicals such as H atoms available in preparatively useful amounts using only inexpensive apparatus. Alkanes can be functionalized in a variety of ways. Several unusual compounds are also available in this way from a variety of alcohols, alkenes, amines, carboxylic acids, ethers, and fluorocarbons. 

Q Propose single-step and multistep syntheses of ketones and aldehydes from alcohols, alkenes, alkynes, carboxylic acids, nitriles, acid chlorides, esters, and aromatic compounds. Problems 18-55, 56, 60, and 64... 

Hydrides from carboxylic acids Carboxylic acids from hydrides Carboxylic acids from hydrides Esters from hydrides Hydrides from aldehydes Hydrides from aldehydes Alkyls from aldehydes Ketones from methylenes Ketones from ketones Alkyls from alkenes... 

Alkynes from halides also alkynes from alkynes Esters from alcohols also esters from carboxylic acids Alkyls from alkenes (Conjugate Reduction)... 

Lipase has been employed to prepare peracids, usually in situ.m The lipase catalysed peracid production from carboxylic acids has been used for the mild epoxidation of alkenes.109 A number of immobilized lipases exist, including one from Candida Antarctica (Novozym 435), which catalyses the conversion of fatty acids to peroxy fatty acids.110... 

Selenocyanates produce selenols or diselenides upon either reduction (e g. with sodium borohydride) or hydrolysis (see Scheme 1). They undergo displacement of the cyanide ion by various nucleophiles and add to alkenes in a maimer similar to selenenyl halides (see equation 14), except that catalysis with Lewis acids is required in the case of unactivated alkenes. The selenocyanates are also popular reagents for the preparation of selenides from alcohols, and (8) from carboxylic acids, as indicated in Scheme 3. 

Determination of the residual antioxidant content in polymers by HPLC and MAE is one way to determine the amoimt needed for reasonable stabilization of a material, and also to compare different antioxidants and their individual efficiencies. During ageing and oxidation of PE, carboxyhc acids, dicarboxylic acids, alcohols, ketones, aldehydes, n-alkanes and 1-alkenes are formed [86-89]. The carboxyhc acids are formed as a result of various reactions of alkoxy or peroxy radicals [90]. The oxidation of polyolefins is generally monitored by various analytical techniques. GC-MS analysis in combination with a selective extraction method is used to determine degradation products in plastics. ETIR enables the increase in carbonyls on a polymer chain, from carboxylic acids, dicarboxyhc acids, aldehydes, and ketones, to be monitored. It is regarded as one of the most definite spectroscopic methods for the quantification and identification of oxidation in materials, and it is used to quantify the oxidation of polymers [91-95]. Mechanical testing is a way to determine properties such as strength, stiffness and strain at break of polymeric materials. 

Examples of alkylation, dealkylation, homologation, isomerization, and transposition are given in Sections 1, 17, 33, and so on, lying close to a diagonal of the index. These sections correspond to such topics as the preparation of acetylenes from acetylenes carboxylic acids from carboxylic acids and alcohols, thiols, and phenols from alcohols, thiols, and phenols. Alkylations that involve conjugate additions across a double bond are given in Section 74E (Alkyls, Methylenes, and Aryls from Alkenes). 

The cyclocondensation of 4-alkoxy-l,l,l-trichloro-3-alken-2-ones with hydroxyl-amine using toluene as solvent is more efficient under the action of microwave irradiation than using the classical method (the average time ratio for the two methods is 1 160) [49]. Katritzky et al. have demonstrated the applicability of microwaves to the synthesis of a variety of 2-oxazolines from readily available N-acylbenzotriazoles and 2-amino-2-methyl-l-propanol under mild conditions (80 °C) with short reaction times (12 min). Use of N-acyl benzotriazoles also avoids some complications in microwave reactions, for example dimerization or the exclusive formation of amides from carboxylic acids [50]. 

Diphasic hydrocarboxylations of alkenes yield carboxylic acids with a typical linear to branched (n/i) ratio which ranges from 1 to 1.4 (Scheme 5). 

Hydrogen peroxide can react with carboxylic acid to form peracid when lipase enzyme is used as a catalyst instead of inorganic acid. The peracid will epoxidize alkenes, which results in the regeneration of the carboxylic acid (Scheme 7). The best results were obtained in the nonpolar solvents toluene and hexane or when mixtures of alkene and carboxylic acid were used without solvent (55). Lipases were immobilized on cellulose, polysulfone membranes, or polypropylene beads (56). The lipases were used to convert caprylic acid to its peracid. The peracid was used to convert oleic acid to its epoxide. The best yield of epoxy stearic acid (81%) was obtained with the lipase from Candida antartica. Using a commercial preparation of immobilized C. antartica lipase, various unsaturated carboxylic acids were treated with... 

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