1: 80 percent / pTsOH / methanol / 6 h / 55 °C 2: 90 percent / H2, quinoline / Lindlar's catalyst / hexane 3: 67 percent / PBr3, pyridine / diethyl ether / 1) overnight, 2) 2 h, reflux 4: 1) Mg / 2) Li2CuCl4 / 1) THF; 2) THF, 5 h, -10 deg C 5: 72 percent / AcOH, pyridine View Scheme

toluene-4-sulfonic acid in methanol Hydrolysis;

1: 90 percent / PTSA / methanol / 2 h / 50 - 60 °C 2: 77 percent / CrO3; H2SO4 / acetone / 2.5 h / 20 °C 3: 64 percent / aq. CrSO4 / dimethylformamide / 72 h / 20 °C View Scheme