1: 96 percent / camphorsulfonic acid / methanol / 6 h / 23 °C 2: 86 percent / Ag2O / dimethylformamide / 21 h / 23 °C 3: 98 percent / Grubbs' 2nd catalyst / benzene / 0.5 h / Heating 4: 72 percent / pyridinium dichromate / 1,2-dichloro-ethane / 8 h / Heating 5: 98 percent / H2 / PtO2 / ethanol / 3 h / 23 °C 6: 96 percent / tetrahydrofuran / 1.5 h / -78 °C 7: 39 percent / Et3SiH; BF3*OEt2 / CH2Cl2; 2,2,2-trifluoro-ethanol / 3 h / -78 °C 8: TFA / CH2Cl2 / 0 - 23 °C 9: 86 percent / N,N-diisopropylethylamine; HATU / acetonitrile / 12 h / 23 °C 10: 67 percent / Grela's catalyst / CH2Cl2 / 9 h / 23 °C 11: 90 percent / tetrahydrofuran / 0 - 23 °C 12: 28 percent / Grela's catalyst / 1,2-dichloro-ethane / 10 h / 23 °C View Scheme