1: Ru(bpy)3Cl2*6H2O; camphor-10-sulfonic acid; 2,6-dimethyl-3,5-diacetyl-1,4-dihydropyridine / tetrahydrofuran; N,N-dimethyl-formamide / 16 h / |Schlenk technique; |Irradiation 2: triethylamine / tetrahydrofuran 3: acetic acid; iron / ethanol / 1.5 h / 80 °C View Scheme

2,6-dimethyl-3,5-diacetyl-1,4-dihydropyridine; camphor-10-sulfonic acid; Ru(bpy)3Cl2*6H2O in tetrahydrofuran; N,N-dimethyl-formamide 16 h; Schlenk techniqueIrradiation; Reagent/catalystConcentration; chemoselective reaction;

2,6-dimethyl-3,5-diacetyl-1,4-dihydropyridine; Ru(bpy)3Cl2*6H2O; acetic acid in N,N-dimethyl-formamide 16 h; Irradiation; Reagent/catalyst; chemoselective reaction;

With  hydrogen; Wilkinson's catalyst in  tetrahydrofuran; tert-butyl alcohol T=20°C; P=760.051 Torr;