di-isopropyl azodicarboxylate; triphenylphosphine in toluene T=0 - 20°C; Mitsunobu reaction; 1.5 h; Inert atmosphere;

1: 88 percent / N-bromosuccinimide (NBS), AgNO3 / acetone / 2 h 2: 1.) mercury(II) trifluoroacetate, 2.) alkaline NaBH4 / 1.) CH2Cl2, RT, 3 h, 2.) 1 h View Scheme