Compound 5

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InChIKey ZTBCCJYBFYTXHT-XQVDCTMKSA-N

Compound data: CIF

Synthetic procedure: See article for the definitive version of this procedure and for full experimental details.

4 (424 mg, 3.2 mmol, 1 eq) was dissolved in triethylaminetrihydrofluoride (2 mL) and was heated by microwave irradiation (50 W, 180 ˚C) in a Teflon flask for 2 h. The reaction mixture was cooled to RT, and the resulting brown residue was reconstituted with ethyl acetate (20 mL) and poured into saturated aqueous sodium hydrogen carbonate solution (20 mL). The layers were separated, and the aqueous phase was re-extracted with ethyl acetate (3 × 15 mL). The combined organic extracts were washed with brine (15 mL), dried over MgSO₄, filtered and concentrated in vacuo, affording a pale brown residue. Purification of the residue by silica gel chromatography, eluting with dichloromethane and methanol (98:2 to 95:5), furnished (1s,2R,3S,4s,5R,6S)-2,3,5,6-tetrafluorocyclohexane-1,4-diol 5 (424 mg, 71%) as a colourless gum, which solidified on standing: ¹H NMR (500 MHz, CDCl₃+MeOD): δ 4.87–4.62 (m, 4H, CHF), 4.43–4.31 (br m, 2H, CHOH); ¹⁹F{¹H} NMR (470 MHz, CDCl₃): δ -209.5 (br s, 4F); HRMS-APCI (m/z): [M+H]⁺ calcd. for C₆H₉F₄O₂, 189.0531; found, 189.0533.