tetrafluoroboric acid; mercury(II) oxide in tetrahydrofuran 0.25 h; Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

tetrafluoroboric acid; mercury(II) oxide in tetrahydrofuran 0.25 h; Heating; Yield given. Yields of byproduct given. Title compound not separated from byproducts;