Tetrabutylammonium Fluoride → (S)-4-(3-Hydroxy-2-methylpropyl]-4H-benzo[1,4]oxazin-3-one

Participants

Reaction Steps

A reaction flask was charged with (S)-4-[3-(tert-Butyldimethylsilanyloxy)-2-methylpropyl]-4H-benzo[1,4]oxazin-3-one (3.92 g, 11.7 mmol), and TBAF (4.78 g, 15.2 mmol) in THF (30 mL) and stirred at rt for 20 h. The reaction mixture was concentrated, dissolved in EtOAc, and washed with brine. The organic layer was dried over Na2SO4, filtered, and concentrated. The product was purified by flash column chromatography (SiO2; n-heptane/EtOAc 3:7) to give the title compound (2.52 g, 98%). 1H NMR (CDCl3) δ 7.05-6.95 (m, 4H), 4.63 (s, CH2), 4.23 (dd, J=10.3 Hz, J=13.9 Hz, 1H), 3.56 (dd, J=4.8 Hz, J=13.9 Hz, 1H), 3.52-3.49 (m, 1H), 3.46-3.38 (m, 1H), 2.92-2.85 (m, 1H), 2.09-1.97 (m, 1H), 1.06 (d, J=7.3 Hz, CH3).

Provenance & Evidence