1: 89 percent / DIBAL / toluene / 20 °C 2: 92 percent / p-TsOH*H2O / CH2Cl2 / 5 h / 20 °C 3: nBuLi; B(O-iPr)3 / tetrahydrofuran; hexane 4: HCl; water / methanol / 3 h / 20 °C View Scheme

diisobutylaluminium hydride in toluene T=20°C;

1: tert-butyl 3-(4-bromophenyl)propanoate With lithium diisopropyl amide in tetrahydrofuran 2: With n-butyllithium in tetrahydrofuran; n-heptane 3: N,N-dimethyl-formamide in tetrahydrofuran; n-heptane