“…(5′-hydroxy-3-methylpent-3′-en-1′-yn-1′-yl)-7,7-dimethyl-6,7-dihydroquinolin-8(5H)-one (6k): n-BuLi (4.2 mL, 10 mmol, 2.4 mol/L) was added dropwise to a solution of (Z)-3-methylpent-2-en-4-yn-1-ol (0.48 g, 5 mmol) in THF (10 mL) at −78 °C under a N 2 atmosphere, and then the mixture was stirred for 1 h at −78 °C. A solution of 4g (0.94 g, 5 mmol) in THF (5 mL) was added slowly, the mixture was stirred for 0.5 h at −78 °C, and then it was warmed to room temperature and stirred for 2 h. The reaction was quenched with saturated aqueous NH 4 Cl solution (10 mL) and extracted with EtOAc (3 × 30 mL). The combined organics were washed with brine (2 × 20 mL), dried over anhydrous Na 2 SO 4 and concentrated.…”