Reaction Steps
A solution of ethylmagnesium bromide in THF (43 ml 1M solution, 43.3 mmol) was added to a solution of z-hept-4-ene-2,6-diyn-1-ol tetrahydropyranyl ether 18 (6.89 g, 36.2 mmol) and 6-methoxy-3-(tert-butyldimethylsiloxy)-quinoline 17 (9.41 g, 32.5 mmol) in THF (210 ml) cooled to 0° C. After the initial evolution of gas the reaction mixture was stirred for 20 minutes at 0° C. and a solution of adamantyl chloroformate (11.51 g, 53.6 mmol) in THF (40 ml) was added via syringe pump over 90 minutes while maintaining the temperature at 0° C. On completion of the addition, the reaction mixture was allowed to warm to room temperature and stirred for 18 hours before quenching with saturated aqueous sodium bicarbonate solution (60 ml). The resulting mixture was extracted with ether (1×300 ml, 2×150 ml), the combined organic extracts dried over magnesium sulphate and evaporated to give a brown oil. Flash column chromatography on silica gel eluting with 80% pentant, 20% diethylether yielded 16.11 g, (75%) of the desired product 19 as a clear yellow oil. 1H NMR (300 MHz, CDCl3) δ7.43 (s, 1H), 6.62 (dd, J=8.8, 2.8 Hz, 1H), 6.52 (d, J=2.8 Hz, 1H), 5.74 (dd, J=11.0, 1.4 Hz, 1H), 5.68-5.79 (s, 1H), 5.67 (d, J=11.0 Hz, 1H 5.62 (s, 1H), 4.75 (s, 1H), 4.31 (dd, J=16.0, 1.4 Hz, 1H), 4.23 (dd, J=16.0, 1.4 Hz, 1H), 3.77-3.89 (m, 1H), 3.76 (s, 3H), 3.46-3.58 (m, 1H), 2.15 (s, 9H), 1.64 (s, 6H), 1.45-1.89 (m, 6H), 0.96 (s, 9H), 0.25 (s, 3H), 0.24 (s, 3H); 13C NMR (75 MHz, CDCl3) δ156.3 (e), 152.0 (e), 128.9 (c), 125.5 (o), 124.8 (e), 119.5 (o), 119.3 (o), 110.5 (o), 109.9 (o), 103.5 (o), 96.8 (o), 93.1 (e), 92.8 (e), 82.7 (e), 81.6 (e), 80.1 (e), 61.9 (e), 55.3 (o), 54.7 (e), 48.8 (o), 41.5 (e), 36.1 (e), 30.9 (o), 30.2 (e), 25.5 (o), 25.3 (e), 1.9.0 (e), 18.1 (e), -4.3 (o), -4.7 (o); IR (CHCl3) 1687 cm-1; MS (FAB) m/e calculated for C39H51NO6Si: 657.349 , found 657.351.
