Divergent Synthesis of Tetrafluoroethylene-Containing Tetrahydrofuran (THF) and Dihydropyran (DHP) Derivatives
Motohiro Yasui1, Suguru Morishitabara1, Shota Kageyama1
1Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan.
Abstract:
A divergent synthetic methodology for tetrafluoroethylene (CF2CF2)-containing tetrahydrofurans (THFs) and dihydropyrans (DHPs), employing 4-bromo-2,2,3,3-tetrafluoro-4-penten-1-ol derivatives as common synthetic intermediates, has been developed. Mechanistic studies indicate that the reaction proceeds chemoselectively, either via copper-catalyzed Ullmann-type intramolecular O-vinylation or through tandem CF2CF2 group-promoted β-elimination followed by 6-endo-dig cycloisomerization. Further investigations demonstrate that both cyclic ethers can be diastereoselectively transformed into a wide range of CF2CF2-containing C-glycoside derivatives.
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