1: diphenyl diselenide With AlCl3, aluminium chloride; zinc in acetonitrile T=70°C; P=760.051 Torr; 1.25 h; Neutral; 2: tetrahydropyran-2-one in acetonitrile T=70°C; P=760.051 Torr; 6 h; Neutral;

in N,N-dimethyl-formamide T=120°C; 3 h;

sodium hydride 1.) THF, reflux, 2.) HMPA, reflux, 3 h; Yield given. Multistep reaction;

1: diethyl ether 2: 1.) ozone / 1.) methylene chloride, -78 deg C, 2.) reflux View Scheme

(i) Et2O, (ii) O3, CH2Cl2, (iii) Py, CHCl3; Multistep reaction;