[431-44-77] · C3H3Cl2FO2 · Methyl Dichlorofluoroacetate · (MW 160.96)
(Reformatsky-type reactions with aldehydes to give 2-fluoroenoates)
Physical Data: bp 82-85 °C/0.5 mmHg.
Solubility: usually used in polar solvents (acetone)
Analysis of Reagent Purity: satisfactory microanalytical data reported.1
The methyl ester of dichlorofluoroacetic acid is a useful reagent in Reformatsky-type reaction with aldehydes (eq 1).2 This procedure allows preparation of 2-fluoroenoates (1) in synthetically useful yields; (Z)-isomers are formed in high preponderance (&egt;93% (Z)-isomer obtained). In the absence of molecular sieves the reaction does not occur.
The use of anhydride sources as an alternative to the simple acetyl anhydride employed in eq 1 has been reported as an improvement to this method (Table 1 and eq 2).3 The same report describes several reactions in which the previously claimed high selectivity for the (Z)-isomer in the alkenation reaction is not observed; up to 40% (E)-alkene is obtained.
University of Bristol, UK