1: 1.) POCl3, 2.) 1N aq. HCl / 1.) reflux, 1 h, 2.) reflux, 1 h 2: 76 percent / K2CO3 / acetone View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: 1.) cetyltrimethylammonium bromide, aq. Na₂S₂O₄, 2.) aq. KOH / 1.) THF, 2.) THF, RT, 14 h<br />2: 88 percent / 2N aq. KOH / 24 h / Ambient temperature<br /> <br /> &nbsp;

<b>Multi-step reaction with 3 steps<br /> </b>1: CsF/celite, 18-crown-6-ether / dimethylformamide / Heating<br />2: 1.) cetyltrimethylammonium bromide, aq. Na₂S₂O₄, 2.) aq. KOH / 1.) THF, 2.) THF, RT, 14 h<br />3: 88 percent / 2N aq. KOH / 24 h / Ambient temperature<br /> <br /> &nbsp;