Alcohols carboxylic acid chlorides

Alcohols react with carboxylic acids to give esters, a reaction that is common in both the laboratory and living organisms. In the laboratory, the reaction can be carried out in a single step if a strong acid is used as catalyst. More frequently, though, the reactivity of the carboxylic acid is enhanced by first converting it into a carboxylic acid chloride, which then reacts with the alcohol. We ll look in detail at the mechanisms of these reactions in Chapter 21. 

Conversion of Acid Chlorides into Alcohols Reduction Acid chlorides are reduced by LiAJH4 to yield primary alcohols. The reaction is of little practical value, however, because the parent carboxylic acids are generally more readily available and can themselves be reduced by L1AIH4 to yield alcohols. Reduction occurs via a typical nucleophilic acyl substitution mechanism in which a hydride ion (H -) adds to the carbonyl group, yielding a tetrahedral intermediate that expels Cl-. The net effect is a substitution of -Cl by -H to yield an aldehyde, which is then immediately reduced by UAIH4 in a second step to yield the primary alcohol. 

The reactive 1-acyl-3-alkylimidazolium species also plays a role in acylation of alcohols with carboxylic anhydrides or carboxylic acid chlorides using 1-substituted imidazoles as catalysts.[145] In this case the reactive species is formed in situ ... 

Carboxylic acid chlorides can be converted to aldehydes by hydrogenolysis on a poisoned Pd/BaS04 catalyst. This is the classic Rosenmund reduction. Over more active catalysts, further hydrogenation gives the corresponding alcohols. Bases are used to react with the HCl. For example, 2,5-dimethylpyridine was used as base in a Rosenmund reduction.457... 

Keywords ketone, aldehyde, carboxylic acid chloride, butyltriphenylphospho-nium tetraborate, alcohol... 

The synthesis of dendritic carbosilanes functionalized with various diphenylphosphino carboxylic acid ester endgroups has also been reported by the Van Koten group in collaboration with Vogt et al. [40,41], The coupling of carbosilane supports containing benzylic alcohol moieties with phos-phinoxy carboxylic acid chlorides resulted in the formation of Go and Gi phosphine oxides, which subsequently were converted into the phosphino... 

In the Friedel-Crafts acylation, carboxylic acid chlorides and carboxylic acid anhydrides are activated with stoichiometric amounts of A1C13 (Section 5.2.7). However, this activation is only possible in the presence of very weak nucleophiles such as aromatic compounds. Stronger nucleophiles would react with the A1C13 instead of the carboxylic acid derivative. If one wants to acylate such stronger nucleophiles—for example, alcohols or amines—with car-... 

The reactions of alcohols with acid chlorides and with acid anhydrides are the most important ways of making esters, but not the only ways, We shall see later how carboxylic acids can be made to react directly with alcohols. 

Silicon halides (especially the readily available chlorides) are probably the most synthetically useful and versatile monomeric inorganic silicon compounds. They may readily be reduced to hydrides, hydrolyzed to silanols (and subsequently to siloxanes), treated with other protic species such as alcohols, carboxylic acids, amines, and thiols to give SiA)R, Si-0C(0)R, Si NR2, and Si SR species respectively, used to make sUyl pseudohalogen derivatives by treatment with silver or alkali metal salts, for example, treated with sodium... 

Preparation of Derivatives. Enoate derivatives were prepared by Homer-Wittig reactions between aldehydes and the ethyl phos-phonate derived from the chloroacetyl ester of (3) in high E) selectivity (97 3). Ester derivatives were obtained by treating alcohol (3) with the corresponding carboxylic acid chloride. ... 

Preparation of Derivatives. Enoate derivatives are prepared from the corresponding chiral alcohol by treatment with acry-loyl chloride in the presence of Triethylamine and catalytic 4-Dimethylaminopyridine or the appropriate carboxylic acid chloride and Silveril) Cyanide. Alkynyl ethers are readily available from the potassium alkoxide by treating with Trichloroethylene, in situ dechlorination with n-Butyllithium, and electrophilic trapping. Trapping the intermediate anion with a proton source or lodomethane followed by Lindlar reduction of the alkynyl ether affords the corresponding vinyl and l-(Z)-propenyl ether, respectively, while reduction of the alkynyl ether with Lithium Aluminum Hydride affords the l-( )-propenyl ether. 

Reductions of carboxylic acid chlorides using NaBH4 in ethereal solvents (dioxane, DME, THF, poly(ethylene glycol) rapidly provide primary alcohols. Reductions in poly(ethylene glycol)- ... 

The compound reacts with alcohols, phenols and amines to form products similar to those obtained from the corresponding reaction with COCI [1358]. Depending upon the conditions and stoicheiometry, carbonates and chloroformates [612,1380], carbamates [1380], isocyanates [1184] and ureas [938] can be obtained with diphosgene, in addition to more complicated products such as carbamoyl chlorides, imidic chlorides, carboxylic acid chlorides, isonitriles and IV-carboxy-Q-amino acid anhydrides [1358]. 

The conversion of alcohol to the half ester of succinic acid ( hemi-succinate ) introduces a carboxyl group available for conjugation. This method (Table 12.6) has been used for a large number of haptens (Steiner et al., 1969 Den Hollander et al., 1974 Okabayashi et al., 1977). The bifunctional reagent, sebacoyldichloride, converts alcohol to acid chloride which, at pH 8.5, reacts readily with proteins (Bailey and Butler, 1967). 

Prim, alcohols from carboxylic acid chlorides... 

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