1: 83 percent / Et4NOTS / methanol / anodic oxidation, carbon rod anode, Pt cathode 2: TiCl4 / CH2Cl2 / 36 h / Ambient temperature 3: 1.) O3, 2.) Zn-dust, HOAc / 1.) MeOH, -78 deg C, 0.5 h, 2.) MeOH, RT, 48 h 4: 38 percent / Et3N / benzene / 0 °C 5: 55 percent / 2,3-dichloro-4,5-dicyanobenzoquinone / dioxane / 3 h / Heating 6: 0.01 N HCl / methanol; H2O / 2 h / 105 °C 7: Bu4NBr, 9 M aq. HBr / 0.75 h / 110 °C View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1: 1.) Et₃N, trimethylaluminum / 1.) CH₂Cl₂, RT, 15 min, 2.) CH₂Cl₂, reflux, 48 h<br />2: Jones reagent / acetone / 2 h / 0 - 20 &deg;C<br />3: benzene / 2.5 h / Heating<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 1.) LDA / 1.) THF, hexane, -45 deg C, 1.5 h, 2.) THF, hexane, -45 deg C, 4.5 h<br />2: 1.) Et₃N, trimethylaluminum / 1.) CH₂Cl₂, RT, 15 min, 2.) CH₂Cl₂, reflux, 48 h<br />3: Jones reagent / acetone / 2 h / 0 - 20 &deg;C<br />4: benzene / 2.5 h / Heating<br /> <br /> &nbsp;