Yield given. Multistep reaction;

Multi-step reaction with 3 steps 1: 99 percent / 1) lithium diisopropylamide / tetrahydrofuran; various solvent(s) / 1) -5 to -15 deg C, 40 min. 2) warming to 10 deg C, 3 h2: 98 percent / polyphosphoric acid, water / 0.5 h / 140 °C3: 1) ethyl chloroformate, triethylamine 2) sodium borohydride / 1) tetrahydrofuran, 5 deg C, 15 min.; 15 deg C, 45 min. 2) water, 40 deg C, 4 h; 20 deg C, 18 h  

With  sodium tetrahydroborate; chloroformic acid ethyl ester; triethylamine  1) tetrahydrofuran, 5 deg C, 15 min.; 15 deg C, 45 min. 2) water, 40 deg C, 4 h; 20 deg C, 18 h;  Yield given. Multistep reaction;