Containing Unsaturated Functional Groups

All of the compounds to be considered in this section have multiple (double or triple) carbon-to-heteroatom bonds. The most common contain the carbon-oxygen double bond (the carbonyl group). 

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Addition of a stabilizing entity into a chain will dramatically change molecular ion intensity. The aromatic nucleus and other conjugate systems are particularly notable in this respect as the radical site may be dispersed by conjugation over an extended part of the ion. Stabilization is also found in compounds containing unsaturated functional groups such as carbonyl, nitro, nitrite, and sulfonyl. 

The reaction is of wide scope (R = alkyl, aryl) however the substrate molecule should not contain other functional groups that can react with diazomethane. With unsaturated acyl halides the yield can be poor, but may be improved by modified reaction conditions. ... 

In reality all carbon atoms share equally the pool of electrons which constitute the double bonds and benzene resists addition across the double bonds which would otherwise destroy its unique structure and stability. Single or multiple hydrogen atoms can be substituted to form a host of derivatives containing similar functional groups to those above, e.g. saturated and unsaturated aliphatic chains, amino, carboxylic acidic, halogeno, nitro, and sulphonic acid groups as shown in Table 3.6. 

In a few cases, 3-hydroxy fatty acids that contain additional functional groups were characterized. Thus (i )-3-hydroxydodec-(5Z)-enoic add [A5-12 l(3-OH)] was identified in ester linkage in lipid A of the chloridazon-de-grading bacterium P. immobile (105). Unsaturated 3-hydroxy fatty adds are also present in R. trifolii (81) and R. meliloti (82). In an extract of L. pneumophila, 2,3-dihydroxy-12-methyltridecanoic acid [12-Me-13 0(2,3-diOH)] and 2,3-dihydroxytetradecanoic acid [ 14 0(2,3-diOH)] were identified in amide-linkage (138). It remains, however, to be established, whether these 2,3-dihydroxylated fatty acids are lipid A constituents. Small amounts of 2-methyl-3-hydroxy-fatty adds have been detected in B. pertussis (139). 

The preparation of polymers from heterocyclic monomers that contain polymerizable functional groups undoubtedly constitutes the most common method of incorporating heterocycles into polymeric materials. Polymer-forming reactions are of two possible types addition reactions and condensation reactions. Addition monomers in general contain a site of unsaturation, i.e. a double or triple bond, through which polymerization occurs by successive single bond formation from one monomer to the next. With condensation monomers a bond is formed between two monomers with concomitant elimination of a... 

The majority of recent publications still deal with the chiral hydrogenation of ketones containing other functional groups as well. The general characteristics of these reactions are illustrated by the asymmetric hydrogenation of a./f-unsaturated ketones. In addition, the purpose of the present review is to summarize the latest results of the chiral hydrogenation of ketones which do not contain other functional groups (dialkyl ketones and alkyl aryl ketones). 

Mixed acetals. A variety of functionalized mixed acetals can be prepared by acc-toxymercuration of a mixture of a vinyl ether and an alcohol followed by demercuration with Na,CS, (10, 369- 570) or, in simple systems, with NaBHj. Unsaturated alcohols can be used, and the vinyl ether can contain various functional groups, although not a cyano group. 

A promising synthetic application for the metathesis reaction concerns unsaturated compounds containing heteroatom functional groups. Metathesis of functionalized acyclic olefins would allow single-step syntheses of various mono- and difunctional derivatives of hydrocarbons with well-defined structures (eq. (7)) X = functional group. 

It is rare today that reduction of ethylenic compounds by zinc and adds has advantages over catalytic hydrogenation however, it is still used for selective reduction of steroids,61 62 unsaturated diketones,62 64 and ethylenic derivatives containing sensitive functional groups.65 The normal method is to use zinc... 

Again, the H NMR helps you, because it contains two signals for methyl groups in the region characteristic of attachment to unsaturated functional groups. The double bond must therefore be between C6 and C7 to be consistent with this observation. The answer is... 

In numerous synthetic studies it has been demonstrated that DMP can be used for a selective oxidation of alcohols containing sensitive functional groups, such as unsaturated alcohols [297,1215-1218], carbohydrates and polyhydroxy derivatives [1216, 1219-1221], silyl ethers [1222,1223], amines and amides [1224-1227], various nucleoside derivatives [1228-1231], selenides [1232], tellurides [1233], phosphine oxides [1234], homoallylic and homopropargylic alcohols [1235], fluoroalcohols [1236-1239] and boronate esters [1240]. Several representative examples of these oxidations are shown below in Schemes 3.349-3.354. Specifically, the functionalized allylic alcohols 870, the Baylis-Hillman adducts of aryl aldehydes and alkyl acrylates, are efficiently oxidized with DMP to the corresponding a-methylene-p-keto esters 871 (Scheme 3.349) [1217]. The attempted Swern oxidation of the same adducts 870 resulted in substitution of the allylic hydroxyl group by chloride. 

Polyfluorinated compounds comprise hundreds of chemicals characterized by hydrophobic linear alkyl chains partially or fully fluorinated (as the perfluorinated compounds [PFCs]) and containing different functional groups. Polyfluorinated compounds include perfluoroalkyl sulfonamides (PFASAs), fluorotelomer alcohols (FTOHs), polyfluorinated alkyl phosphates (PFAPs), fluorotelomer unsaturated carboxylic acids (FTUCAs), perfluoroalkyl acids (PFAAs), and their salts. The most common PFAAs are perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFASs). In particular, PFASs contain one or more fluorinated alkyl chains bonded to a polar head, which at neutral pH can be charged (anionic, cationic, and amphiphilic surfactants) or noncharged (nonionic surfactants). 

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