1: 96 percent / Zn/Ag / tetrahydrofuran; ethanol; diethyl ether / 12 h / 45 °C 2: 4-(dimethylamino)pyridine, pyridine / 2.5 h 3: HOAc, H2O / tetrahydrofuran / 168 h / 50 °C View Scheme

<b>Multi-step reaction with 3 steps<br /> </b>1: 61 percent / tetrahydrofuran / 1 h / Heating<br />2: 96 percent / Bu₄NF / tetrahydrofuran / 1 h / 0 &deg;C<br />3: Na₂HPO₄, m-chloroperoxybenzoic acid / CH₂Cl₂ / 3 h / 23 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: pyridinium p-toluenesulfonate / CH₂Cl₂ / 16 h / 25 &deg;C<br />2: 86 percent / 0.3 N aq. NaOH / tetrahydrofuran; methanol / 2.5 h / 25 &deg;C<br />3: 77 percent / NaHCO₃, N-bromosuccinimide / acetonitrile / 2 h / 23 &deg;C<br />4: Na₂HPO₄, m-chloroperoxybenzoic acid / CH₂Cl₂ / 3 h / 23 &deg;C<br /> <br /> &nbsp;