1: 1.) LDA / 1.) hexane, THF, -78 deg C, 10 min, 2.) reflux, 2h 2: 1.) LDA / 1.) hexane, THF, -78 deg C, 10 min, 2.) reflux, 2h 3: 5percent aq. NaOH 4: diethyl ether / 0.5 h / 0 °C View Scheme

Multi-step reaction with 4 steps 1: 80 percent / conc. HCl / 0.02 h / Heating2: 1.) TMEDA, n-BuLi / 1.) hexanes, a.) -78 deg C, 60 min b.) RT, 1.5h; 2.) RT 3h.3: diisobutylammonium hydride / CH2Cl2; hexane / 3 h / -78 °C4: 75 percent / triethylamine, DMAP / CH2Cl2 / 0.5 h / 0 °C