triethylamine; isobutyl chloroformate 1.) diethyl ether, tetrahydrofuran, -20 deg C, 15 min 2.) diethyl ether, tetrahydrofuran, 1 h at -10 deg C then 12 h at 5 deg C; Yield given. Multistep reaction;

(i) SOCl2, Et2O, (ii) Et3N; Multistep reaction;

1: 77 percent / bromine, Et3N / CDCl3 / 0.25 h / -30 °C 2: LiAlH4 / tetrahydrofuran; diethyl ether / below -30 deg C View Scheme