Acetic caproic anhydride

This is an unsymmetrical anhydride. The I.U.P.A.C. names of the two parent carboxylic acids are ethanoic acid (two-carbon) and hexanoic acid (six-carbon). To name an unsymmetrical anhydride, the term anhydride is preceded by the names of the two parent acids. The I.U.P.A.C. name of this compound is ethanoic hexanoic anhydride. The common names of the two parent carboxylic acids are acetic acid and caproic acid. Thus, the common name of this compound is acetic caproic anhydride. 

In a modification of this scheme, hydroxypregnenolone is first acetylated under mild conditions to the 3-acetate and then under forcing conditions with caproic anhydride to give the acetate-caproate (122). Ester interchange with methanol removes the acetate at 3 Oppenauer oxidation affords hydroxyprogesterone caproate (124). ... 

To resolve any uncertainty caused by the difference between acetate and caproate in the active substrate an experiment was attempted using caproic anhydride as the substrate. The reaction could not be followed, however, presumably because of the low solubility of caproic anhydride. 

It is imperative to continue the distillation at atmospheric pressure until conversion of any mixed anhydride to caproic anhydride is complete. The acetic acid formed by this conversion comes off very slowly, and approximately three hours are necessary to complete the distillation at atmospheric pressure. 

M-Caproic anhydride has been prepared by heating caproic acid with acetic anhydride,3 by heating sodium caproate and acetic anhydride in a sealed tube,4 by the action of phosphorus oxychloride on barium caproate,6 by the action of acetyl chloride on caproic acid,6 and by treating a mixture of sodium caproate and sulfur with chlorine.7 The method used in the present synthesis was first described by Hurd and Dull.8... 

Acetic acid is quantitatively converted to acetic anhydride by reaction with ketene. Mixed anhydrides are formed when homologs of acetic acid or aromatic acids are used in the reaction. Upon distillation at atmospheric pressure, the mixed anhydrides disproportionate into acetic anhydride and the symmetrical anhydride corresponding to the carboxylic acid. Yields of propionic, n-butyric, and w-caproic anhydrides prepared by this method are in the range of 80% to 87%. ... 

Pyridine is used in catalytic amounts and acylpyridinium salts are assumed to be the reactive acylating agents. The method can be applied to the synthesis of both symmetrical and unsymmetrical acid anhydrides. " These can also be obtained in many cases directly from the acid halide and the sodium carbox-ylate without using a solvent or a catalyst. Tiiis approach has been described for a number of mixed acid anhydrides. Thus acetic palmitic anhydride (70%), butyric myristic anhydride (81%) and caproic lauric anhydride (85%) were prepared by heating the components for 2 h at 90 °C. 75 These anhydrides were successfully employed for the N-acylation of amino sugars. 7 ... 

Acetic anhydride [ 1 ] Phenyl acetic anhydride Caproic anhydride [4] Glutaric anhydride [6]... 

Hydrogen chloride 17a-Oxypregnene-(5)-ol-(3)-one-(20)-acetate-(3) Cyclohexanone Caproic acid anhydride... 

Butyl peroxylri methyl acetate, see Butyl peroxypivalate Butyl vinyl ether n-Butyraldehyde iso-Butyraldehyde n-Butyric acid iso-Butyric acid n-Butyric anhydride 2-Butyrolactone n-Butyronitrile Butyryl chloride Camphor Caproic acid... 

Direct bromination of an acid yields the a-substituted product when red phosphorus or phosphorus halides are used as carriers. The procedure is illustrated by the preparation of a-bromo-n-caproic acid (89%) and a-bromoisovaleric acid (89%)." An excellent laboratory preparation of bromoacetic acid is furnished by a modification of the reaction in which acetic anhydride with pyridine is used as the catalyst. ... 

The reaction has been extended to the acylation of di-f-butylamine with silico anhydrides of acetic, butyric and caproic acids. Ethylamine 2ilso reacts readily with these reagents. 

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