Electrolytic partial fluorination of organic compounds. 79. Anodic fluorination of spiropyrazoline-5,3'-chroman-4-ones and thiochromanone analogues. A route to aroyl fluoride derivatives.

[reaction: see text] Anodic fluorination of spiropyrazole-5,3'-chroman-4-ones and their thiochromanone analogues in dimethoxyethane containing Et4NF x 4HF resulted in ring opening of spiroheterocycles, which led to the formation of (5-pyrazolyl)methyl o-carbomethoxyphenyl ethers and their thioether analogues via benzoyl fluoride derivatives.