Taming elemental fluorine: Indirect use of fluorine for the synthesis of α-fluoroketones[1]

Fluorine and sodium trifluoroacetate react at -75° to produce a variety of fluoroxy-compounds. Although it is possible to direct the reaction towards the formation of CF₃COOF or CF₃CF₂OF, mixtures may be used when only the electrophilic fluorine has to be attached to the molecule of interest. Such is the case of the reaction of enol-acetates with the mixture of the fluoroxy reagents. A wide variety of compounds, including steroids and containing various functional groups, were tested. In most cases the desired α-fluoroketones were obtained in good to very good yields. The new fluorine containing compounds are the compounds numbered 2, 9, 11, 13, 15, 16 and 20.