trifluoroacetic acid in tetrahydrofuran; water Heating;

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: 53 percent / p-TsOH / benzene / 3 h / Heating 2: 1.) aq. NaOH, tetrabutylammonium hydrogensulfate / 1.) CH2Cl2, 0 deg C, 20 min, 2.) CH2Cl2, 20 h 3: 1.) n-BuLi, N,N,N,N-tetramethylethane diamine / 1.) Et2O, hexane, RT, 2h, 2.) Et2O, hexane, RT, 12 h 4: 72 percent / TFA / tetrahydrofuran; H2O / Heating View Scheme

1: 1.) n-BuLi, N,N,N,N-tetramethylethane diamine / 1.) Et2O, hexane, RT, 2h, 2.) Et2O, hexane, RT, 12 h 2: 72 percent / TFA / tetrahydrofuran; H2O / Heating View Scheme