1: 1.) aq. NaOH, tetrabutylammonium hydrogensulfate / 1.) CH2Cl2, 0 deg C, 20 min, 2.) CH2Cl2, 20 h 2: 1.) n-BuLi, N,N,N,N-tetramethylethane diamine / 1.) Et2O, hexane, RT, 2h, 2.) Et2O, hexane, RT, 12 h 3: 72 percent / TFA / tetrahydrofuran; H2O / Heating View Scheme

1: 100 percent / K2CO3 / acetone / 12 h / Heating 2: TMEDA / tetrahydrofuran; diethyl ether / 0.5 h / -40 °C 3: 569 mg / aq. HCl / tetrahydrofuran / 5 h / 20 °C View Scheme