in toluene T=165°C; 6 h;

1: 61 percent / HCl; acetic acid / Heating 2: diisopropylethylamine / dimethylformamide / 100 °C 3: 1.24 g / chromium(II) chloride / tetrahydrofuran / 5 h / 0 °C 4: 77 percent / trifluoroacetic acid / CH2Cl2 / 1 h / 20 °C View Scheme

acid hydrolysis;