1.1: potassium carbonate / N,N-dimethyl-formamide / 12 h / 20 °C 2.1: sodium methylate / tetrahydrofuran; methanol / 20 °C 2.2: ion-exchange resin / 0.5 h 3.1: Pearlman's catalist; hydrogen / tetrahydrofuran; ethanol / 12 h View Scheme