[Li].[CH3:2][Si:3]([CH3:11])([C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)Cl.[SiH3][Li].[F:14][C:15](F)=[CH2:16]>C1COCC1>[F:14][C:15]([Si:3]([CH3:11])([CH3:2])[C:5]1[CH:10]=[CH:9][CH:8]=[CH:7][CH:6]=1)=[CH2:16]To a suspension of 4.4 g of lithium wire cut into small pieces in 200 mL of anhydrous THF stirred under argon and cooled on ice (internal temperature <10° C.) was added dimethylphenyl-chlorosilane in 5 mL portions over 1 hour. The deep red color of the silyl lithium reagent appeared after approximately 0.75 hour. The mixture was stirred on ice for an additional 5 hours (internal temperature remained between 5° C. and 10° C.). The mixture was cooled on a dry ice/acetone bath and 1,1-difluoroethylene was introduced by filling a balloon connected to the reaction mixture and the reagent cylinder using a three-way valve. The balloon was filled with 1,1-difluoroethylene and emptied into the reaction mixture 10 times. The mixture was allowed to warm to room temperature (effervescence observed, probably from unreacted 1,1-difluoroethylene). The mixture was diluted with 200 mL of hexanes and filtered through a cotton wool plug. The filtrate was washed with water, dried, filtered, and concentrated in vacuo. Four fractional distillations under vacuum through a Vigreux column gave 4.6 g of product.
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