1.1: 95 percent / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone; p-TsOH*H2O / dioxane / 2.5 h / 50 °C 2.1: sodium dithionite / ethyl acetate; methanol; H2O / 4 h / 20 °C 3.1: n-BuLi / tetrahydrofuran; hexane / 0.33 h / -78 °C 3.2: 88.8 mg / tetrahydrofuran; hexane / 1.5 h / -78 - 0 °C 4.1: 90 percent / benzene / 36 h / 80 °C 5.1: 92 percent / methanolic HCl / CH2Cl2 / 30 h / 20 °C View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1.1: n-BuLi / tetrahydrofuran; hexane / 1.5 h / 0 &deg;C<br />1.2: isopropyl borate / tetrahydrofuran; hexane / 0.83 h / 0 &deg;C<br />1.3: 87 percent / AcOH; aq. H₂O₂ / tetrahydrofuran; hexane / 16 h / 0 - 20 &deg;C<br />2.1: 89 percent / pyridine / 2.5 h / 0 &deg;C<br />3.1: 96 percent / KBr; K₃PO₄ / (Ph₃P)4Pd / dioxane / 26 h / 100 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1: 89 percent / pyridine / 2.5 h / 0 &deg;C<br />2: 96 percent / KBr; K₃PO₄ / (Ph₃P)4Pd / dioxane / 26 h / 100 &deg;C<br /> <br /> &nbsp;