Dimethylformamide → (2RS,4SR)-4-(Benzyloxy)-2-fluoro-cyclohexan-1-one

Participants

Reaction Steps

A N,N-dimethylformamide (150 mL) solution of {[4-(Benzyloxy)cyclohex-1-en-1-yl]oxy}(tert-butyl)dimethylsilane (23.2 g, 73.0 mmol) was cooled in an ice bath under nitrogen and to this was added Selectfluor™ (51.6 g, 146 mmol) in several portions. After 1 h the contents of the reaction flask were poured into 5% sodium bicarbonate. The resulting mixture was extracted with ethyl acetate (4×) and the combined organic extracts were washed successively with water and brine, dried with anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. Flash column chromatography (hexane:ethyl acetate, 80:20) gave 4-(Benzyloxy)-2-fluorocyclohexanone as a pale oil (10.0 g, 62% yield): 1H NMR (CDCl3) δ 7.39-7.30 (m, 5H), 5.36-5.19 (m, 1H), 4.61 (s, 2H), 4.02 (m, 1H), 2.81-2.73 (m, 2H), 2.45-2.41 (m, 1H), 2.36-2.30 (m, 1H), 2.05-1.88 (m, 1H), 1.85-1.77 (m, 1H).

Provenance & Evidence