triphenylphosphine; diethylazodicarboxylate in tetrahydrofuran T=0 - 25°C;

1: 1) K2CO3 2) HCl aq. (10percent) / 1) acetone, 70 deg C, 8 h 2) room temp. 2: 87 percent / triphenylphosphine, diethyl-azodicarboxylate / tetrahydrofuran / 1 h / Ambient temperature View Scheme

1: 1) boric acid, 2) water / 1) 90 deg C, 10 h 2) room temp., 1 h 2: 1) K2CO3 2) HCl aq. (10percent) / 1) acetone, 70 deg C, 8 h 2) room temp. 3: 87 percent / triphenylphosphine, diethyl-azodicarboxylate / tetrahydrofuran / 1 h / Ambient temperature View Scheme

1: NaOH / H2O / 60 °C 2: 87 percent / diethylazodicarboxylate, PPh3 / tetrahydrofuran / 0 - 25 °C View Scheme