Reaction of α-halogen-substituted fluorine-containing β-keto acids with ho- and hs-nucleophiles

1. Using1H and19F NMR spectroscopy, it was shown that for methyl esters of fluoroalkyl-containing a-chloro-substituted β-keto acids, the keto form is most reactive in reactions with HO-nucleophiles (water, methanol) and HS-nucleophiles (ethyl mercaptan), in contrast to the β-keto esters which do not contain α-halogens. 2. Methyl esters of fluoroalkyl-containing α,α-dibromo-substituted β-keto acids form adducts at the keto group with methanol and ethyl mercaptan, and with acetone give β-keto esters unsubstituted by bromine at the a position and bromoacetone. The latter reaction is accelerated by both acid and basic catalysts.