1: (S)-1,2-epoxyperillyl alcohol With periodic acid in tetrahydrofuran T=0°C; 0.25 h; 2: trimethyl orthoformate With toluene-4-sulfonic acid in methanol Heating; Further stages.;

1.1: 98 percent / VO(acac)2; tert-butyl hydroperoxide / CH2Cl2; various solvent(s) / 1 h / 0 °C 2.1: H5IO6 / tetrahydrofuran / 0.25 h / 0 °C 2.2: 75 percent / p-TsOH / methanol / Heating View Scheme

1: periodic acid / tetrahydrofuran; H2O / 0 - 20 °C 2: p-TsOH View Scheme

toluene-4-sulfonic acid Yield given;