1: 79 percent / Sn, HBr / diethyl ether; H2O / Ambient temperature 2: 43 percent / (n-Bu)3SnCl, NaCNBH3, AIBN / 2-methyl-propan-2-ol / 72 h / Heating View Scheme

2,2'-azo-bisisobutyronitrile; tributyltin chloride; sodium cyanoborohydride in tert-butyl alcohol 72 h; Heating;