1: 1.) camphorsulfonic acid, 2.) n-Bu4NF / 1.) room temperature, 2.) dioxane-THF, 65 deg C 2: 88 percent / H2 / Lindlar / methanol 3: 1.) DMSO, (COCl)2, Et3N, 2.) CSA / 1.) CH2Cl2, 2.) CH2Cl2, room temperature 4: 23 percent / (C6H11)2NMgBr / tetrahydrofuran / -55 °C 5: 95 percent / DDQ / CH2Cl2; H2O / 0.17 h / Ambient temperature 6: 70 percent / TFA, molecular sieves / CH2Cl2 View Scheme