Tetrahydrofuran → (S)-4,4,6-Trifluoro-1-isopropyl-3,4-dihydronaphthalen-2(1H)-one

Participants

Reaction Steps

4,4,6-Trifluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalene-1,2-diol (62): A THF solution (8 mL) of 2-((tert-butyldimethylsilyl)oxy)-4,4,6-trifluoro-3,4-dihydronaphthalen-1(2H)-one 54 (0.585 g, 1.77 mmol) was cooled to 0° C. and a solution of hydrogen fluoride in pyridine (70%, 200 μL) was added dropwise. The reaction was allowed to warm to ambient temperature over 12 h at which point the reaction was quenched with an aqueous solution of saturated sodium bicarbonate, volatiles were removed and the mixture was re-dissolved in ethyl acetate. The aqueous phase was extracted with ethyl acetate (3×), dried over sodium sulfate, filtered and concentrated to give an orange oil. The desired product, 4,4,6-trifluoro-2-hydroxy-3,4-dihydronaphthalen-1(2H)-one, was purified with a gradient heptanes/ethyl acetate eluent system on silica gel by a ISCO companion system to give the desired product as a colorless oil (0.263 g, 1.22 mmol, 69% yield). 1H NMR (400 MHz, CDCl3) δ: 8.14 (dd, J=8, 4 Hz, 1H), 7.48 (dt, J=8, 4 Hz, 1H), 7.36 (m, 1H), 4.67 (ddd, J=12, 8, 4 Hz, 1H), 3.66 (s, 1H), 3.17 (m, 1H), 2.54 (m, 1H).

Provenance & Evidence