1: tetrahydrofuran / 0.25 h / -20 °C 2: 1) CuI, methyl sulfide, 2) p-chloranil / 1) THF, -20 deg C, 15 min, then r.t. 15 min, 2) toluene, reflux, 10 h 3: tetrahydrofuran / 0.25 h / -20 °C 4: tetrahydrofuran / 0.25 h / -20 °C 5: o-chloranil / toluene / 12 h / Heating View Scheme

1: 1) CuI, methyl sulfide, 2) p-chloranil / 1) THF, -20 deg C, 15 min, then r.t. 15 min, 2) toluene, reflux, 10 h 2: tetrahydrofuran / 0.25 h / -20 °C 3: tetrahydrofuran / 0.25 h / -20 °C 4: o-chloranil / toluene / 12 h / Heating View Scheme

1: tetrahydrofuran / 0.25 h / -20 °C 2: tetrahydrofuran / 0.25 h / -20 °C 3: o-chloranil / toluene / 12 h / Heating View Scheme

1: tetrahydrofuran / 0.25 h / -20 °C 2: 1) CuI, methyl sulfide, 2) p-chloranil / 1) THF, -20 deg C, 15 min, then r.t. 15 min, 2) toluene, reflux, 10 h 3: tetrahydrofuran / 0.25 h / -20 °C 4: tetrahydrofuran / 0.25 h / -20 °C 5: o-chloranil / toluene / 12 h / Heating View Scheme

1: tetrahydrofuran / 0.25 h / -20 °C 2: o-chloranil / toluene / 12 h / Heating View Scheme