Ethyl Acetate → (2S,3S)-2-(4-Fluorophenyl)-3,5,5-trimethylmorpholin-2-ol

Participants

Reaction Conditions

Reaction Steps

A solution of 15 (166 mg, 1.16 mmol) in dry THF (1.2 mL, 1M) under an N2 atmosphere was cooled to −78° C. and treated with 4-fluorophenylmagnesium bromide (1.3 equiv., 1.5 mmol, 1.9 mL, 0.8 M solution in THF). The reaction mixture was stirred at −78° C. for 3 h. A saturated aqueous solution of NH4Cl was added to the reaction vessel, and the mixture was allowed to warm to room temperature. EtOAc (5 mL) was added to the reaction vessel and the organic layer was separated. The aqueous phase was extracted with EtOAc (three times). The combined organic extracts were washed (water, brine), dried (Na2SO4) and concentrated. The residue was purified by column chromatography on silica gel using CH2Cl2 to CH2Cl2-MeOH (90:10) as the eluent to afford 80 mg of 4h as a white solid: [α]22D +31.2° (c 0.5, CHCl3); 1H NMR (CDCl3) δ 7.60-7.55 (m, 2H), δ 7.08-7.00 (m, 2H), 3.83 (d, 1H, J=11.3 Hz), 3.40 (d, 1H, J=11.3 Hz), 3.17 (q, 1H, J=6.4 Hz), 1.38 (s, 3H), 1.08 (s, 3H), 0.78 (d, 3H, J=6.4 Hz); 13C NMR (CDCl3) δ 128.0, 127.9, 114.87, 114.58, 103.2, 98.4, 96.8, 69.5, 53.5, 27.3, 22.8, 16.4; LCMS (ESI) m/z 240.0 [(M+H)+, M=C13C18FNO2].

Provenance & Evidence