1: 85 percent / 1) toluene p-sulfonic acid hydrate; 2) HBr / CH2Cl2; methanol / 16 h 2: 42 percent / trifluoroacetic acid / 0.25 h / Ambient temperature 3: 54 percent / 3percent aqeous sodium hydroxide / pyridine / 2.5 h / Heating View Scheme

<b>Multi-step reaction with 4 steps<br /> </b>1: 94 percent / Ni-montmorillonite / CH₂Cl₂ / 1 h<br />2: 67 percent / H₂, Et₃N / 10percent Pd/C / Ambient temperature<br />3: p-toluenesulfonic acid monohydrate / CH₂Cl₂; methanol / 0.67 h / 22 &deg;C<br />4: CaCO₃, POCl₃ / CH₂Cl₂ / 1.5 h / 20 &deg;C<br /> <br /> &nbsp;

<b>Multi-step reaction with 6 steps<br /> </b>1: 1) sulfuryl chloride; 2) sodium acetate / 1) CCl₄, 3h, room temperature; 2) dioxan/water, reflux, 2h, room temperature<br />2: 80 percent / sodium bicarbonate, iodine, potassium iodide / methanol; H₂O / 60 &deg;C<br />3: 90 percent / zinc dust, acetic acid / 3 h / Heating<br />4: 77 percent / p-toluene sulfonic acid hydrate / acetic acid / 4 h / 45 &deg;C<br />5: 98 percent / triethylamine, H₂ / 10percent palladised charcoal / tetrahydrofuran / 760 Torr / Ambient temperature<br />6: 1) p-toluene sulfonic acid hydrate; 2) calcium carbonate, phosphoryl chloride / 1) dichloromethane, methanol, 40 min, room temperature; 2) 1.5h, room temperature<br /> <br /> &nbsp;

<b>Multi-step reaction with 4 steps<br /> </b>1: 82 percent / lead tetra-acetate / acetic acid<br />2: 77 percent / p-toluene sulfonic acid hydrate / acetic acid / 4 h / 45 &deg;C<br />3: 98 percent / triethylamine, H₂ / 10percent palladised charcoal / tetrahydrofuran / 760 Torr / Ambient temperature<br />4: 1) p-toluene sulfonic acid hydrate; 2) calcium carbonate, phosphoryl chloride / 1) dichloromethane, methanol, 40 min, room temperature; 2) 1.5h, room temperature<br /> <br /> &nbsp;

<b>Multi-step reaction with 5 steps<br /> </b>1: 80 percent / sodium bicarbonate, iodine, potassium iodide / methanol; H₂O / 60 &deg;C<br />2: 90 percent / zinc dust, acetic acid / 3 h / Heating<br />3: 77 percent / p-toluene sulfonic acid hydrate / acetic acid / 4 h / 45 &deg;C<br />4: 98 percent / triethylamine, H₂ / 10percent palladised charcoal / tetrahydrofuran / 760 Torr / Ambient temperature<br />5: 1) p-toluene sulfonic acid hydrate; 2) calcium carbonate, phosphoryl chloride / 1) dichloromethane, methanol, 40 min, room temperature; 2) 1.5h, room temperature<br /> <br /> &nbsp;

<b>Multi-step reaction with 2 steps<br /> </b>1: p-toluenesulfonic acid monohydrate / CH₂Cl₂; methanol / 0.67 h / 22 &deg;C<br />2: CaCO₃, POCl₃ / CH₂Cl₂ / 1.5 h / 20 &deg;C<br /> <br /> &nbsp;