1: AcOK / ethanol / 0.33 h / Ambient temperature 3: 85 percent / tetrahydrofuran / 0.5 h / Ambient temperature 4: 85 percent / DDQ, CSA / benzene / 5 h / Heating 5: 87 percent / 1N HCl / 12 h / Heating View Scheme

2: 85 percent / tetrahydrofuran / 0.5 h / Ambient temperature 3: 85 percent / DDQ, CSA / benzene / 5 h / Heating 4: 87 percent / 1N HCl / 12 h / Heating View Scheme

1: Na2S2O4 / CHCl3; H2O / Ambient temperature 2: Me3SiBr / CH2Cl2 / 0.17 h / Heating 3: AcOK / ethanol / 0.33 h / Ambient temperature 5: 85 percent / tetrahydrofuran / 0.5 h / Ambient temperature 6: 85 percent / DDQ, CSA / benzene / 5 h / Heating 7: 87 percent / 1N HCl / 12 h / Heating View Scheme

1: Me3SiBr / CH2Cl2 / 0.17 h / Heating 2: AcOK / ethanol / 0.33 h / Ambient temperature 4: 85 percent / tetrahydrofuran / 0.5 h / Ambient temperature 5: 85 percent / DDQ, CSA / benzene / 5 h / Heating 6: 87 percent / 1N HCl / 12 h / Heating View Scheme

1: 72 percent / CAN / ethanol; H2O / -40 - 0 °C 2: Na2S2O4 / CHCl3; H2O / Ambient temperature 3: Me3SiBr / CH2Cl2 / 0.17 h / Heating 4: AcOK / ethanol / 0.33 h / Ambient temperature 6: 85 percent / tetrahydrofuran / 0.5 h / Ambient temperature 7: 85 percent / DDQ, CSA / benzene / 5 h / Heating 8: 87 percent / 1N HCl / 12 h / Heating View Scheme

1: 90 percent / (i-Pr)2NEt / tetrahydrofuran / 3 h / Heating 2: 94 percent / LiAlH4 / diethyl ether / 1 h / Heating 3: 72 percent / CAN / ethanol; H2O / -40 - 0 °C 4: Na2S2O4 / CHCl3; H2O / Ambient temperature 5: Me3SiBr / CH2Cl2 / 0.17 h / Heating 6: AcOK / ethanol / 0.33 h / Ambient temperature 8: 85 percent / tetrahydrofuran / 0.5 h / Ambient temperature 9: 85 percent / DDQ, CSA / benzene / 5 h / Heating 10: 87 percent / 1N HCl / 12 h / Heating View Scheme

1: 67 percent / AlBr3 / tetrahydrothiophene / 4.5 h / Ambient temperature 2: LDA / dimethylformamide / 1.) -78 deg C to RT, 2.) RT, 30 min 3: 2.) 3 M HCl / 1.) THF, RT, 30 min; 2.) THF, RT, 10 min 4: 85 percent / dl-10-camphorsulfonic acid (CSA), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 5 h / Heating 5: 87 percent / 1 M HCl / 15 h / Heating View Scheme

1: 85 percent / dl-10-camphorsulfonic acid (CSA), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 5 h / Heating 2: 87 percent / 1 M HCl / 15 h / Heating View Scheme