F. Tellier et R. Sauvetre, STEREOSELECTIVE INTRODUCTION OF THE DIFLU OROMETHYLENE GROUP IN THE ALLYL POSITION, Journal of fluorine chemistry, 70(2), 1995, pp. 265-270
The regio- and stereo-selective introduction of a difluoromethylene gr
oup in an allylic position is described. The key step is the treatment
of 1,1-difluoro-1-alken-3-acetates with Grignard reagents in the pres
ence of copper and lithium salts.