1: 23 percent / tetrahydrofuran; diethyl ether / 1.) - 100 deg C, 15 min, 2.) - 100 deg C - - 50 deg C, 1 h 2: 90 percent / lithium triethylborohydride / tetrahydrofuran / 1.) - 78 deg C, 3 h, 2.) - 78 deg C - room temperature, 3 h View Scheme