potassium tert-butylate in tert-butyl alcohol 0.5 h; Heating;

1: 74 percent / KO-t-Bu / 2-methyl-propan-2-ol / 0.5 h / Heating 2: 1.) O3, 2.) dimethyl sulfide / 1.) CH2Cl2, -78 deg C, 2.) CH2Cl2, RT, 12 h 3: 1.) KH / 1.) THF, RT, 2.) THF, from -78 deg C to RT 4: 83 percent / aq. NaOH / 48 h View Scheme

1: 74 percent / KO-t-Bu / 2-methyl-propan-2-ol / 0.5 h / Heating 2: 1.) O3, 2.) dimethyl sulfide / 1.) CH2Cl2, -78 deg C, 2.) CH2Cl2, RT, 12 h View Scheme

1: H2SO4, AcOH 2: Zn, AcOH View Scheme