Functional groups, organic ester

In addition to aldehydes and ketones, other organic molecules containing an electron-withdrawing functional group such esters, amides, nitriles, and nitro compounds can undergo aldol-like reactions as long as they contain a-hydrogen. Similarly, linear or branched alcohols can be synthesized by aldol condensation of short-chain linear alcohols (7,8). 

Functional Groups Organic compounds with similar fxmctional groups form a family of compounds and exhibit similar chemical and physical properties. For example, carboxylic acids behave as acids and therefore have low pH. Many esters, aldehydes, and ketones, especially those that contain an aromatic ring in their R group, tend to have pleasant smells. Amines, on the other hand, tend to have foul smells. 

In this contribution, we will only consider polymers with longer i/segments (alkyl and perfluoroalkyl units directly linked via C—C— bond, not by functional groups like ester, amide, and urethane as, for instance, in References 39 and 40). Only /segments able to self-organize will be discussed. We will comment only briefly on polymers with short i/groups such as trifluoroethyl groups. Reviews about this polymer type... 

The oxidation of higher alkenes in organic solvents proceeds under almost neutral conditions, and hence many functional groups such as ester or lac-tone[26,56-59], sulfonate[60], aldehyde[61-63], acetal[60], MOM ether[64], car-bobenzoxy[65], /-allylic alcohol[66], bromide[67,68], tertiary amine[69], and phenylselenide[70] can be tolerated. Partial hydrolysis of THP ether[71] and silyl ethers under certain conditions was reported. Alcohols are oxidized with Pd(II)[72-74] but the oxidation is slower than the oxidation of terminal alkenes and gives no problem when alcohols are used as solvents[75,76]. 

The chemistry of carboxylic acids is the central theme of this chapter The impor tance of carboxylic acids is magnified when we realize that they are the parent com pounds of a large group of derivatives that includes acyl chlorides acid anhydrides esters and amides Those classes of compounds will be discussed m Chapter 20 Together this chapter and the next tell the story of some of the most fundamental struc tural types and functional group transformations m organic and biological chemistry... 

The carbon-carbon bond forming potential inherent m the Claisen and Dieckmann reac tions has been extensively exploited m organic synthesis Subsequent transformations of the p keto ester products permit the synthesis of other functional groups One of these transformations converts p keto esters to ketones it is based on the fact that p keto acids (not esters ) undergo decarboxylation readily (Section 19 17) Indeed p keto acids and their corresponding carboxylate anions as well lose carbon dioxide so easily that they tend to decarboxylate under the conditions of their formation... 

Miscellaneous Curing Reactions. Other functional groups can react with the thiol terminal groups of the polysulfides to cross-link the polymer chains and build molecular weight. For example, aldehydes can form thioacetals and water. Organic and inorganic acids or esters can form thioesters. Active dienes such as diacrylates can add to the thiols (3). Examples of these have been mentioned in the Hterature, but none have achieved... 

Liquid-Phase Components. It is usual to classify organic Hquids by the nature of the polar or hydrophilic functional group, ie, alcohol, acid, ester, phosphate, etc. Because lowering of surface tension is a key defoamer property and since this effect is a function of the nonpolar portion of the Hquid-phase component, it is preferable to classify by the hydrophobic, nonpolar portion. This approach identifies four Hquid phase component classes hydrocarbons, polyethers, siHcones, and duorocarbons. 

Amides, like esters, are abundant in all living organisms—proteins, nucleic acids, and many pharmaceuticals have amide functional groups. The reason for this abundance of amides, of course, is that they are stable to the conditions found in living organisms. Amides are the least reactive of the common acid derivatives and undergo relatively few nucleophilic acyl substitution reactions. 

Although a polyfunctional organic molecule might contain several different functional groups, we must choose just one suffix for nomenclature purposes. It s not correct to use two suffixes. Thus, keto ester 1 must be named either as a ketone with an -one suffix or as an ester with an -oate suffix but can t be named as an -onoate. Similarly, amino alcohol 2 must be named either as an alcohol (-0/) or as an amine (-amine) but can t be named as an -olamine or -anritiol. 

Ester An organic compound containing the —C—O— functional group, 595-596... 

Hydrozirconation of various alkenylboranes [118-121] and alkenylzinc halides [34] with 1 provides the corresponding 1,1-bimetalloalkanes, which can be selectively converted to functionalized organic compounds [122-125]. Interestingly, alkenylzinc halides (RCH=CHZnX) show remarkable chemoselectivity, and functional groups such as chloride, cyanide, or ester functionality are tolerated [126]. 

Suitable reagents for derivatizing specific functional groups are summarized in Table 8.21. Many of the reactions and reagents are the familiar ones used in qualitative analysis for the characterization of organic compounds by physical means. Alcohols are converted to esters by reaction with an acid chloride in the presence of a base catalyst (e.g., pyridine, tertiary amine, etc). If the alcohol is to be recovered after the separation, then a derivative which is fairly easy to hydrolyze, such as p-nltrophenylcarbonate, is convenient. If the sample contains labile groups, phenylurethane derivatives can be prepared under very mild reaction conditions. Alcohols in aqueous solution can be derivatized with 3,5-dinitrobenzoyl chloride. 

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