sodium hydroxide; sodium cyanoborohydride; acetic acid in tetrahydrofuran

1: 93 percent / Et3N / tetrahydrofuran / 1 h / Ambient temperature 2: 1) 50 percent NaH / 1.) oil, DMF, RT, 1 h; 2.) DMF, oil, RT, 1.5 h 3: 1) CF3COOH; 2) HCl / CH2Cl2 / 2 h View Scheme

1: 93 percent / Et3N / tetrahydrofuran / 1 h / Ambient temperature 2: 1) 50 percent NaH / 1.) oil, DMF, RT, 1 h; 2.) DMF, oil 3: 1) CF3COOH; 2) HCl / CH2Cl2 / 2 h View Scheme