1: BH3*THF / tetrahydrofuran / 7 h / 0 °C 2: lead tetraacetate / benzene / 2 h / 5 °C View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1.1: 17.6 g / red mercuric oxide; concentrated sulfuric acid; water / acetone / 1.75 h / 60 &deg;C<br />2.1: lithium diisopropylamide; LiCl / tetrahydrofuran; hexane / 1 h / -78 &deg;C<br />2.2: 70 percent / tetrahydrofuran; hexane / 4 h / -78 &deg;C<br />3.1: 90 percent / imidazole / dimethylformamide / 17 h / 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 90 percent / tetrahydrofuran / -78 - 20 &deg;C<br />2: 85 percent / HgO, H₂SO₄ / acetone / Heating<br />3: 75 percent / LDA, LiCl / tetrahydrofuran / 4 h / -78 &deg;C<br />4: 90 percent / imidazole / dimethylformamide / Ambient temperature<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1.1: butyllithium / tetrahydrofuran; hexane / 0.75 h / -78 - -70 &deg;C<br />1.2: tetrahydrofuran; hexane / -78 - 20 &deg;C<br />2.1: 17.6 g / red mercuric oxide; concentrated sulfuric acid; water / acetone / 1.75 h / 60 &deg;C<br />3.1: lithium diisopropylamide; LiCl / tetrahydrofuran; hexane / 1 h / -78 &deg;C<br />3.2: 70 percent / tetrahydrofuran; hexane / 4 h / -78 &deg;C<br />4.1: 90 percent / imidazole / dimethylformamide / 17 h / 20 &deg;C<br /> <br /> &nbsp;