Carboxylic acids, by oxidation

This procedure illustrates a general method for the preparation of aromatic carboxylic acids by oxidation of the corresponding alkylarenes.2 For example, 2-naphthoic acid (360 g., 93% yield m.p. 184-185°) was obtained from 2-methylnaphthalene (320 g., 2.25 moles), sodium dichromate (975 g., 3.26 moles, 45% excess), and water (1.81.). 

Quinoxaline-2-carboxaldehyde has been converted into the 2-carboxylic acid by oxidation with potassium permanganate in acetone and reduced to the 2-hydroxymethyl compound by treatment with formalin and potassium hydroxide. It also undergoes other typical reactions of aromatic aldehydes such as benzoin formation on reaction with potassium cyanide - and condensation reactions with malonic acid and its diethyl ester and Schiff base formation. Acid-catalyzed reaction of quinoxaline-2-carboxaldehyde with ethylene glycol gives the cyclic acetal the diethylacetal has been prepared by reaction of 2-dibromomethylquinoxaline with sodium ethoxide. " An indirect preparation of the oxime 11 is achieved by treatment of 2-nitromethyl-quinoxaline (10) with diazomethane followed by thermolysis of the resulting nitronic ester. 

Homologues of thiophene occur in coal-tar they may be prepared by Fittig s synthesis and in other ways. Their properties are similar to those of the analogous benzene derivatives for example, thiotolene, methyl thiophene, is converted into thiophene carboxylic acid by oxidizing agents —... 

Potassiumltert-butanol-oxygen Carboxylic acids by oxidative desulfuration... 

The reaction with Af-Boc protected allyl amine was carried out in a 10 mmol scale with a ratio of substrate/Rh = 10 000 1 for 24 h without affecting the regio-and stereochemistry found in the prehminary screening (Scheme 4.79). The iV-mono-protected P -amino aldehyde was converted into the corresponding P -amino carboxylic acid by oxidation or into the corresponding 1,3-hydroxy amine by reduction. Both are valuable chiral building blocks. 

The minor is-o-butanal isomer R-CH-(CHO)-CH3 also forms. The aldehydes are intermediates of choice for the synthesis of alcohols (by hydrogenation), leading to detergents and plastifiers, and for the synthesis of carboxylic acids (by oxidation using Oi). For instance, propionic acid is synthesized from ethylene via propanal. 

Alcohols are converted to carboxylic acids by oxidation reactions. 

A study of the addition of dilithium carboxylates to acyclic enones under conditions of kinetic control has revealed that the reaction is irreversible and that the intrinsic preference for [1,2] addition may be completely changed to [1,4] when large groups are present on the acid or adjacent to the ketone group. The acid-catalysed decomposition of a-hydroperoxy-ketones to acids and ketones has been studied in detail in some cases, yields of acids can be excellent. 1,3-Dioxolans can be converted into the corresponding carboxylic acids by oxidative bromination followed by reduction with zinc under various conditions (Scheme 2). Readily available tetra-n-butylammonium permanganate (3) prom-... 

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