An efficient method for α-monofluorination of carbonyl compounds with molecular fluorine: Use of α-hydroxymethylene substituent as directing and activating groups

Article abstract of DOI:10.1016/S0040-4039(96)02378-7

Molecular fluorine efficiently reacts with α-hydroxymethylene carbonyl compounds to give α-fluoro-α-formyl compounds in a highly site-specific manner. The fluorinated compounds mostly isolated as their hemiacetals with methanol are readily deformylated just by treatment with weak bases affording α-monofluorinated carbonyl compounds. In this fluorination method, the hydroxymethylene group serves not only as a directing group but also as the activating group of carbonyl compounds for fluorination. By this method, a series of α-fluoro carbonyl compounds including esters was synthesized in high yields.