New approach to 3,3-difluoroallyl alcohol

A new difluoroalkene with a triethylsilyl group, 4,4-difluoro-3-(triethylsilyl)- but-3-en-1-ol (1), was synthesized as a new building block for 1,1-difluoro-1-alkenes. Treatment of 1 with sodium hydride in the presence of a catalytic amount of p-methoxyphenol induced SiCsp2 bond dissociation. Subsequent addition of an aldehyde to the reactive intermediate afforded 3,3-difluoroallyl alcohol (9). The reaction was accelerated by added p-methoxyphenol.

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► This is the first synthesis of 4,4-difluoro-3-(triethylsilyl) but-3-en-1-ol (1).
► 1 generates 2,2-difluorovinylanion by treatment of 1 with NaH.
► The generated 2,2-difluorovinylanion attacks to aldehydes.
► 1 serves good building block for introducing 2,2-difluorovinyl unit.