1.1: NaOH / ethanol / 5 h / 20 °C 1.2: 99 percent / dimethylformamide / 12 h / 3 °C 2.1: 97 percent / PDC / dimethylformamide / 16 h / 20 °C 3.1: LDA / tetrahydrofuran / -78 °C 3.2: 60 percent / TiCl3; Li / 1,2-dimethoxy-ethane / 24 h / Heating View Scheme