Willgerodt-Kindler oxidation

The oxidative cyclisation of the disulfide 71 derived from a Willgerodt-Kindler thiolation of dimedone affords the 4,1,2-oxadithiin 72 <07HCA1606>. 

Wacker oxidation, 6, 302,416 Warburganal, 246 Wichterle reagent, 134 Willgerodt-Kindler reaction, 229 Williamson ether synthesis, 92, 194, 395 Wolff-Kishner reaction, 225, 339... 

Diphenylguanidine was successfully used as starting material for the Willgerodt-Kindler reaction, giving polythioamides. Carbon disulphide reacted with triethylamine and DMF to give A /Z-diethyl- and i W-dimethyl-thioformamide. Under the same conditions, dithiocarbamates decompose to give iViV-dialkyl-thioformamide and sulphur. HMPT and sulphur have been shown to be a useful system for the oxidation of a variety of aromatic and heteroaromatic compounds to the corresponding A -methyl- and JVAT-dimethyl-thioamides in the case of phenyl benzyl ketone, /mn -stilbene and the heterocyclic compounds (114) and (115) have been obtained as by-products. Whereas the benzylic... 

It has been tentatively suggested that one mechanism underlies the Willgerodt reaction and the Kindler modification of it. A labile intermediate is first formed which has a carbon—carbon bond in the side chain. The scheme is indicated below it postulates a series of steps involving the addition of ammonia or amine (R = H or alkyl), elimination of water, re addition and eUmination of ammonia or amine until the unsaturation appears at the end of the chain then an irreversible oxidation between sulphur and the nitrogen compound may occur to produce a thioamide. 

Willgerodt Oxidation of Ketones to Carboxylic Adds (Kindler Mo[Pg.282]

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