Reaction Steps
To a stirred solution of hex-1-yne (1.23 g, 15 mmol) in dry THF (40 ml) was added n-butyl lithium (6 ml of 2.6M, 15 mmol) at -78° C. under a nitrogen atmosphere. After 15 minutes, a solution of 2,2-dimethyl-1-fluoro-4-(1H-1,2,4-triazol-1-yl)-pentan-3-one (2.5 g, 13 mmol) in dry THF (20 ml) was added dropwise. Upon complete addition the mixture was allowed to warm to room temperature and stirred for 18 hours. The reaction mixture was then poured onto ice and extracted with ether (2×250 ml). The ethereal solution was washed with saturated brine solution then dried over anhydrous magnesium sulphate and the solvent removed. The resulting yellow oil was chromatographed (silica gel, petrol/diethyl ether elution) to give a yellow gum (2.0 g, 56.5%) which was a mixture of the RS/SR and the RR/SS forms. This gum was then purified by preparative chromatography to give the pure RS/SR form as a white solid (0.24 g, 6.8%), mp. 72°-74° C. (Found: C, 63.5; H, 9.0; N, 15.0C15H24FN3O requires C, 64.1; H, 8.5; N, 14.95%); IR 3200, 2950, 2225, 1360, 1280, 1200, 1140, 1000, 870, 680 cm-1 ; NMR (90 MHz; CDCl3) 0.8 (6H, s); 0.9 (3H, t, J 7 Hz); 1.2-1.56 (4H, m); 1.72 (3H, d, J 6.3 Hz); 2.24 (2H, m); 3.8 (1H, br); 4.36 (2H, dq, J 46.8 and 6.3 Hz), 4.8 (1H, q, J 6.3 Hz); 7.95 (1H, s); 8.24 (1H, s); m/z 282 (M+H+) 206, 185, 109, 97 (100%), 82. The RR/SS component could not be isolated in a pure state thus, a 1:1 mixture of the RS/SR and RR/SS forms was obtained as a yellow oil (0.34 g, 9.6%); NMR (90 MHz; CDCl3) 0.8 (6H, s); 0.92 (3H, t, J 7 Hz); 1.2-1.56 (4H, m); 1.66 (3H, d, J 6.3 Hz); 2.13 (2H, m); 3.8 (1H, br); 4.36 (2H, dq, J 46.8 and 6.3 Hz), 4.76 (1H, q, J 6.3 Hz); 7.93 (1H, s); 8.26 (1H, s); m/z 282 (M+H+), 206, 185, 109, 97 (100%), 82.
