Trichloroacetyl chloride → N-[(1S)-2-Hydroxy-1,2-dimethylpropyl]-2,2,2-trichloroethanamide

To a solution of (3) (1.193 g, 8.56 mmol) at 0° C. in pyridine (24 ml) was added trichloroacetyl chloride (1.05 ml, 9.41 mmol). After stirring at this temperature for 10 minutes, the reaction mixture was stirred overnight at room temperature. The reaction was quenched by the addition of saturated aqueous sodium chloride solution, after which the product was extracted with dichloromethane and the combined organic extracts were washed with hydrochloric acid (1M). Concentration in vacuo and purification by flash column chromatography using 30% ethyl acetate/40-60 petroleum ether as eluant furnished the title compound (4) (1.992 g, 94%) as an oil; νmax (CH2Cl2) 1713 cm-1 ; [α]D24 (c 1.2 in CHCl3)=+6.3; (Found: C, 33.71; H, 5.12; N, 5.72. C7H12Cl3NO2 requires C, 33.83; H, 4.87; N, 5.64%); δH (200 MHz; CDCl3) 1.21 (3H, d, J=3.4, CH3CH), 1.25 (3H, s, C(CH3)2), 1.26 (3H, s, C(CH3)2), 2.31 (1H, s, OH), 3.82 (1H, dq, J=6.7 and 8.8, CHCH3NH), 7.1 (1H, s, NH); δC (125 MHz; CDCl3) 14.89 (CH3), 26.68 (CH3), 27.56 (CH3), 55.19 (CH), 72.01 (C), 92.82 (CCl3), 161.56 (CO); m/z (CI+, NH3) 248 (M+).