1: 72 percent / sodium methoxide / methanol / 20 h 2: 89 percent / m-chloroperbenzoic acid / CH2Cl2 / 0.5 h / Ambient temperature 3: 43 percent / N-chlorosuccinimide NCS, triethylamine / CH2Cl2 / Ambient temperature 4: 1.) H2S, CH3COONa, 2.) manganese dioxide / 1.) MeOH, reflux, 6 h, 2.) CHCl3, reflux, 6 h View Scheme