1: 95 percent / TsOH / benzene / Heating 2: 1) O3, 2) LAH / 1) AcOEt, -78 deg C, 2) THF, r.t. 3: 89 percent / PDC, pyridine / CH2Cl2 / Heating 4: 75 percent / benzene / Heating 5: 98 percent / H2 / Pd / ethyl acetate / Ambient temperature View Scheme

in benzene T=0 - 20°C;