1: tetrahydrofuran; hexamethylphosphoric acid triamide / 16.5 h / 65 °C 2: 100 percent / H2 / Lindlar catalyst / benzene 3: (CH2SH)2, TSOH / CHCl3 / 3 h / 60 °C 4: Pb(OAc)4 / benzene / 1 h / Ambient temperature 5: 60 percent / benzene / 6 h / 80 °C 6: 65 percent / DBU, LiCl / acetonitrile / 1 h / Ambient temperature 7: AlH3 / tetrahydrofuran / 2.5 h / 0 °C 8: CBr4, DIPHOS / CH2Cl2 / 2.5 h / -35 °C 9: acetonitrile / 2.5 h / Ambient temperature 10: 1.) BuLi 2.) HMPT / 1.) THF, -100 deg C, 2 min; 2.) -100 deg C to RT 11: nBu4NF / tetrahydrofuran 12: K2CO3 / methanol; H2O View Scheme