0 33 mol in tetrahydrofuran 600 ml at u2212 70 u00b0 c is treated with 1 bromo 4 fluorobenzene 33 0 ml 0 30 mol stirred at u2212 70 u00b0 c for 90 minutes and added to a solution of trimethyl borate 41 0 ml 0 36 mol in diethyl ether 300 ml at u2212 70 u00b0 c the resulting solution is stirred at u2212 70 u00b0 c for 15 minutes warmed to 15 u00b0 c over 90 minutes treated with acetic acid 51 5 ml 0 9 mol and water 375 ml and stirred at room temperature for 30 minutes the organic layer is separated and the aqueous layer is extracted with ether the organic extracts are combined with the organic layer and the resulting solution is washed sequentially with 10 hydrochloric acid and brine dried over anhydrous magnesium sulfate and concentrated in vacuo to give the title product as an off white solid 65 g 99 yield advantageously the present invention also provides a process for the preparation of a fluoroolefin compound of formula i ar is phenyl optionally substituted with any combination of from one to three halogen c 1 c 4 alkyl c 1 c 4 haloalkyl c 1 c 4 alkoxy or c 1 c 4 haloalkoxy groups or 1 or 2 naphthyl optionally substituted with any combination of from one to three halogen c 1 c 4 alkyl c 1 c 4 haloalkyl c 1 c 4 alkoxy or c 1 c 4 haloalkoxy groups r is hydrogen and r 1 is cyclopropyl or r and r 1 are each independently c 1 c 4 alkyl or r and r 1 are taken together with the carbon atom to which they are attached to form a cyclopropyl group and.