1: bis-diphenylphosphine With cesium hydroxide monohydrate in N,N-dimethyl-formamide T=20°C; 1 h; Molecular sieveInert atmosphere; 2: 1,2-dibromo-propane in N,N-dimethyl-formamide T=20°C; 72 h; Inert atmosphereMolecular sieve;

in tetrahydrofuran T=-78 - 20°C; Schlenk technique;

8 h; Irradiation;