1: 54 percent / LDA / tetrahydrofuran / -50 - 0 °C / other reagent, temperature, reaction time 2: O2, salcomine / dimethylformamide / 2 h / Ambient temperature 3: methanol / 23 h / Ambient temperature View Scheme

1: 54 percent / LDA / tetrahydrofuran / -50 - 0 °C / other reagent, temperature, reaction time 2: O2, salcomine / dimethylformamide / 2 h / Ambient temperature 3: NH4Cl / methanol / 13 h / Ambient temperature View Scheme