in tetrahydrofuran T=35 - 40°C; 1.5 h;

1: 32 percent / tetrahydrofuran / 1.5 h / 35 - 40 °C 2: 1.) diborane; 2.) NaOH, H2O2 / 1.) THF, r.t.; 2.) alcohol, reflux View Scheme