Alkanoyl Chlorides

The reaction of chlorosulfonic acid with the first three alkanoyl chlorides was extensively investigated by Krajcinovic and afforded some interesting results which were reviewed by Jackson.  

Propanoyl chloride 109 was reacted with an equal weight of chlorosulfonic acid at room temperature (5-10 days), poured onto cold water and extracted with ether to give a mixture of sulfopropionic acid 110 (from the aqueous layer) and a 

C -Dialkylthiophosphoric acids, e.g. the 2-ethylhexyl derivative 114 R = CH2CH(Et)(CH2)3Me, react with chlorosulfonic acid (one equivalent) in liquid sulfur dioxide at —23 to —17 °C to give the corresponding thiosulfonic acid 115 (Equation 44).  

Chlorosulfonic acid reacts with unsaturated carboxylic acids with oleic acid (ci5-9-octadecenoic acid) the reagent gives sulfooleic acid with loss of hydrogen chloride. On the other hand, with 10-undecenoic acid the product was hydro-xysulfoundecenoic acid in which hydroxyl and sulfonic acid groups have added across the double bond.  

Chlorosulfonic acid reacts with a mixture of a long chain aliphatic carboxylic acid and pentamethylene oxide with cleavage of the cyclic ether, yielding a long chain alkyl sulfate 116 (Equation 45).  

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Alkanoyl chlorides and chloroformates can be treated with potassium fluoride and benzyItriethylammonium chloride to obtain the respective alkanoyl fluorides or fluoroformates [62]. 2-Amino-6-chloro-9-(2,3,5-tri-0-acetyl-P-D-ribofurano-syl)purine is converted to the 2-amino-6-fluoro product with potassium fluoride and trimethylamme in dimethylformamide under rigorously anhydrous conditions [65] (equation 37)... 

Ether formation from alcohol and alkanoyl chloride Wacker-Chemie Bachhuber (1993)... 

Ethyl 3-oxoalkanoates when not commercially available can be prepared by the acylation of tert-butyl ethyl malonate with an appropriate acid chloride by way of the magnesium enolate derivative. Hydrolysis and decarboxylation in acid solution yields the desired 3-oxo esters [59]. 3-Keto esters can also be prepared in excellent yields either from 2-alkanone by condensation with ethyl chloroformate by means of lithium diisopropylamide (LDA) [60] or from ethyl hydrogen malonate and alkanoyl chloride usingbutyllithium [61]. Alternatively P-keto esters have also been prepared by the alcoholysis of 5-acylated Mel-drum s acid (2,2-dimethyl-l,3-dioxane-4,6-dione). The latter are prepared in almost quantitative yield by the condensation of Meldrum s acid either with an appropriate fatty acid in the presence of DCCI and DMAP [62] or with an acid chloride in the presence of pyridine [62] (Scheme 7). 

The reduction of aroyl chlorides take a different course in the presence of Ni(ll) salts. Reaction is best effected in an undivided cell with a nickel anode and a nickel foam cathode with acetonitrile containir tetrabutylammonium fluoroborate as electrolyte. Symmetrical ketones are formed [173], Substimted benzoyl chlorides yield the benzophenone in 47-72% yields. Phenacetylchloride also gives the ketone in good yield but in general, alkanoyl chlorides do not react. 

On the other hand, upon reaction with methyl glyoxalate imines, an increase in bulk of the silyl moiety [i.e., PhMe2Si, Ph2MeSi, Ph3Si and (t-Bu)Ph2Si] in fi-(triorganosilyl)alkanoyl chlorides causes a moderate increase in the anti/syn ratio of the [2 + 2] a. v-adducts113. Little effect on the cis/trans ratio is observed. 

Intramolecular acylation of alkylsilanes. Cyclopentanones can be prepared by ring closure of 5-(trimethylsilyl)alkanoyl chlorides mediated by AlCl,. The starting materials are readily available from alkylation of the dianion of a carboxylic acid with a 3-(trimethylsilyl)alkyl bromide or iodide (equation 1). 

The fluorovinyllithium reagents are thermally unstable (vu/e supra) and are reacted with electro-philes at low temperatures. These reagents undergo usual reactions with a variety of electrophiles including ketones, esters, alkanoyl chlorides, epoxides (e.g.. formation of 6 ), oxetanes, carbon dioxide, sulfur dioxide, tin and silicon halides, and trifluoromethancsulfonates. The reaction of 2,2-difluoro-1 -(tosyloxy)vinyllithium (5) with trialkylboranes followed by a second electrophile is an attractive route to functionalized 1.1-difluoroalkenes. e.g. 7. ... 

The Michaelis-Arbuzov reaction works well for the less complex aroyl and alkanoyl chlorides, where purification by distillation is possible. Moreover, there has been less success in the preparation of oc,P-unsaturated acylphosphonates, where multiple addition products are often observed. Recourse has been found in an attractive route that entails oxidation of dialkyl 1-hydroxyalkyl- or 1-hydroxyaryIphosphonates produced by nucleophilic addition of dialkyl phosphites to carbonyl compounds under basic conditions (Pudovik reaction). Alkali metal salts of dialkyl phosphites are currently used in the Pudovik reaction, and the more common procedure of generating the anion involves the addition of a small amount of alcoholic alkoxide ion to the reaction mixture. Neutral amines represent an alternative to the use of anionic bases. In recent years, the use of solid-phase materials as basic catalysts has been successfully developed (Scheme 7.7). One system involves the addition of basic alumina to the carbonyl compound and dialkyl phosphite the other involves the addition of KF or CsF to the mixture of carbonyl compound and dialkyl phosphite. - Such a process for generating dialkyl 1-hydroxyalkyIphosphonates is very flexible and accommodates a large variety of carbonyl compounds. 

Electrophilic reactions. Asymmetric bromination of alkanoyl chlorides with 1,1,3,6-tetrabromo-l,2-dihydronaphthalen-2-one is catalyzed by the quinine - derived 3, it affords (5)-a-bromoaIkanoic esters on alcoholysis of the products Quatemization of quinine with... 

More than one approach can be used for both (a) and (b) one based on Friedel-Crafts acylation (acylation), which uses an alkanoyl chloride, and another using Grignard addition to an aldehyde or a ketone. 

Method I Direct reaction between an amine and an acid first gives a salt strong heating converts the salt to the amide with loss of water. Method 2 Converts to alkanoyl chloride reaction with amine gives amide with loss of HCI. Often done in the presence of excess amine to consume the HC1. Method 3 Esterification with any inexpensive alcohol (ethanol chosen here), then reaction with the amine under mild heating. 

In the classical sarcosinate procedure, the appropriate alkanoyl chloride is treated with sodium sarcosinate (worldwide capacity amounts to more than 10,000 tonnes annually). In contrast, amidocarbonylation offers the advantage that no salt is formed as a by-product. 

In situ prepared ketene by dehydrochlorination of the corresponding acyl chloride with Hiinig s base, afforded similar results [262c]. A further modification was the dimerization of ketenes 182 in situ formed from different alkanoyl chlorides to afford 3,4-dialkyl-ci5-a-Iactone derivatives [262d]. 

A series of efficient hydrogelators based on the core L-Iys unit and two long aliphatic chains, one carrying a positively charged heteroaromatic group, have been prepared (Scheme 16). Synthesis starts with esterification of N -lauroyl-L-lysine by ethanol, methanol, or 11-bromoundecanol followed by an acylation step with alkanoyl chloride or n-bromoalkanoyl chloride and subsequent quaternization of pyridine or methyhmidazole [56,57]. Such gela-tors are able to gel water at a mgc of 1 - 3 g L . ... 

Section 18.3.1, the key step is the preparation of PFCA fluorides by electrochenaical fluorination from the corresponding alkanoyl chlorides or fluorides. - Compared to perfluorooctanesul-fonyl surfactants (see Section 18.2), the production volume of PFCA fluorides by electrochemical fluorination was much smaller. For example, the U.S. production of ammonium perfluorooctanoate... 

Tetronic Acids.—a-Alkoxytetronic acids (and ultimately a,a -dihydroxy-ketones) can be obtained from a-hydroxy-acids by condensation with a-bromo-alkanoyl chlorides to give lactides which undergo base-induced ring contraction (Scheme 19). °"... 

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