1: With potassium tert-butylate in tetrahydrofuran T=-78°C; 0.166667 h; 2: With sulfuric acid in ethylene glycol dimethyl ether T=-78°C; 0.166667 h;

1: t-BuOK / tetrahydrofuran / 0.17 h / -78 °C 2: aq. sulfuric acid / tetrahydrofuran; 1,2-dimethoxy-ethane / 0.17 h / -78 °C View Scheme