camphor-10-sulfonic acid in benzene T=-20 - -10°C; 0.5 h; Irradiation;

1: 1.) oxalylchloride, DMF, 2.) pyridine / 1.) benzene, overnight, RT 2.) benzene, 30 min, RT 2: 70 percent / camphor sulphonic acid / benzene / 0.5 h / -20 - -10 °C / Irradiation View Scheme

dihydrogen peroxide; potassium carbonate in tetrahydrofuran; methanol T=40°C; 15 h;