potassium hexamethylsilazane 1) THF, -78 deg C, 45 min, 2) THF, -78 deg C, 10 min; Multistep reaction;

1: 1)O3, 2) methylsulfide / 1) CH2Cl2, -78 deg C, MeOH, 2) -78 deg C to r.t. 2: LiOH*H2O, H2O / tetrahydrofuran / 0.5 h 3: diethyl ether / 0 deg C to r.t., 1.5h View Scheme

1: 1)O3, 2) methylsulfide / 1) CH2Cl2, -78 deg C, MeOH, 2) -78 deg C to r.t. 2: LiOH*H2O, H2O / tetrahydrofuran / 0.5 h View Scheme