Monobasic ketonic acids

The anhydride of sedanonic acid, Cj HjgOj, is not a lactone, but an anhydride resulting from the elimination of a molecule of water from a monobasic ketonic acid. Sedanonic anhydride occurs in oil of celery. The acid, which melts at 113°, has the following constitution —... 

Passerini, M. isonitriies. ii. Compounds with aidehydes or with ketones and monobasic organic acids. Gazz. Chim. Ital. 1921,51, 181-189. 

In the form indicated above, the reaction is not capable of general application but a reaction closely related to it, discovered by Claisen and W. Wislicenus, is of general applicability, and is of great value in synthetical operations for this reason it will be briefly mentioned here. If sodium alcoholate is allowed to act on a mixture of the esters of two monobasic acids, a ketone acid-ester, having a constitution analogous to that of acetacetic ester,is formed by the action of the sodium alcoholate on one of the esters with the elimination of alcohol, e.g.. -... 

If a mixture of monobasic acids is employed, the mixed ketone may be pre- ... 

The Kabachnik-Fields reaction is the three-component condensation of an aldehyde or ketone, an amine (secondary, primary, or ammonia) and a monobasic phosphorus(III) acid to yield an a-amino organophosphorus compound (a phos-phonate, phosphinate, or tertiary phosphine oxide) Scheme 28. It was discovered independently in 1952 by Kabachnik and Medved 120 and Fields,121 and may be regarded as a variant of the Pudovik reaction (Section 6), which was discovered contemporarily. The yields of the reaction tend to be only moderate (cf. Section 6), and are generally unsatisfactory with phosphinate reactants, but it is wide in scope and simple to perform. For a recent review of the Kabachnik-Fields reaction, including discussion of the mechanism (which usually proceeds via the imine), see Ref. 102. 

Isatin forms orange prisms, ] I.P. 200°. It is sparingly soluble in water, easily in alcohol and ether. It possesses the properties of a weak monobasic acid, but also reacts like the aldehydes and ketones for example, it combines with bisulphites of the alkalies, and with phenylhydrazine and its sulphonic acids [65]. 

Reformatsky, S. New synthesis of monobasic acids from ketones. Ber. 1887, 20,1210-1211. 

---