1: 98 percent / Al(Hg) / tetrahydrofuran; H2O 2: enzyme View Scheme

aluminum amalgam in tetrahydrofuran; water

Multi-step reaction with 4 steps 1: 99 percent / KOH / methanol / 0.5 h2: 88 percent / trifluoroacetic acid, 1,3-dicyclohexylcarbodiimide / benzene; pyridine; dimethylsulfoxide / 18 h3: 1.) n-BuLi; 2.) CuI-Bu3P, and Bu3P / 1.) THF, -78 deg C, 20 min, 30 min; 2.) THF, ether, -78 deg C 10 min, - 30 deg C 1 h; 3.) THF, ether, HMPA, -30 deg C, 3 h4: 78 percent / pyridine, 50percent aq. HF / 1.) 0 deg C, 30 min; 2.) rt, 4.5 h