1: in tetrahydrofuran T=65°C; Cycloaddition; 16 h; 2: With ammonium cerium(IV) nitrate; water; nitric acid in diethyl ether Oxidation;

1: in 1,2-dichloro-ethane T=83°C; Doetz benzannulation; 18 h; 2: With ammonium cerium(IV) nitrate; nitric acid in 1,2-dichloro-ethane 0.5 h; Further stages.;

ammonium cerium(IV) nitrate in water; acetonitrile T=0°C; 2 h;