Polyfluoro-2-alkynoic acids

Yamanaka and co-workers (74) effected the 1,3-dipolar cycloaddition between miinchnones 134 and polyfluoro-2-alkynoic acid esters to afford the corresponding 4-(polyfluoroalkyl)pyrrole-3-carboxylates (135). The reaction proceeds rapidly at low temperature and the various miinchnones (134) were generated from 1,3-oxazolium perchlorates 133 using the method of Boyd and Wright (6,7). Under... 

The addition of ethanedithiole to polyfluoro-2-aLkynoic acids gives the 2-carbox-ymethyT2-polyfluoroalkyl-1,3 -dithiolanes 186. ... 

Yamanaka, H. Tamura, K. Funabiki, K. Fukunishi, K. Ishihara, T. Reactions of polyfluoro-2-alkynoic acids with bifunctional hetero nucleophiles leading to polyfluoroalkylated heterocycles. J. Fluorine Chem. 1992, 57, 177-190. 

Fluoroalkyl chromone derivatives can be obtained from the base catalysed reaetion between 2,2-dihydropolyfluoroalkanoates and phenols. Initial loss of HF allows Michael addition of the phenol and subsequent cyclisation of the enol ether yields the heterocycle. m-Substituted phenols give the expected mixture of 5- and 7-substituted chromones, whilst dihydroxy aromatic compounds give polycyclic materials (94JFC263). In a more conventional approach Z-3-(aryloxy)-polyfluoroalkenoic adds, derived from Michael addition of phenols to polyfluoro-2-alkynoic acids, undergo intramolecular Friedel-Crafts acylation to 2-polyfluoro-alkylchromones (94JFC25). 

Funabild K, Ishihara T, Yamanaka H (1995) An efficient and convenient synthesis of 4-polyfluoroalkylated pyrrole-3-carboxylates through 1,3-dipolar cycloaddition reaction of polyfluoro-2-alkynoic acid esters with munchnones. J Fluor Chem 71 5-7... 

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