Zn(N3)2/bis-pyridine complex; 2,2'-azo-bisisobutyronitrile; di-isopropyl azodicarboxylate; tri-n-butyl-tin hydride; triphenylphosphine 1.) toluene, room temperature, 24 h, 2.) benzene, reflux, 23 h; Yield given. Multistep reaction;