1: 93 percent / NaBH4 / aq. ethanol; tetrahydrofuran / 1.5 h / 20 °C 2: 100 percent / BnEt3NCl, 50percent aq. NaOH / toluene / 0.5 h / 80 °C 3: 6N HCl / CH2Cl2 / 0.75 h / 20 °C View Scheme

1: 1) tBuOK / 1) DME, -40 deg C, 3 min, 2) DME, -40 to 20 deg C, 1.5 h 2: 90 percent Spectr. / 40percent HClO4 / CH2Cl2 / 0.05 h / 20 °C View Scheme

Yield given. Multistep reaction;

1: KOH / tetrahydrofuran / 1 h / Ambient temperature 2: 100 percent / NaBH4, NaOH / tetrahydrofuran; ethanol / 65 h / Ambient temperature 3: 94 percent / 4 N H2SO4 / tetrahydrofuran / 70 h / Ambient temperature View Scheme

<b>Multi-step reaction with 2 steps<br /> </b>1: t-BuOK / tetrahydrofuran / 2 h / -40 &deg;C<br />2: 85 percent / i-Pr₂NH, POCl₃ / tetrahydrofuran / 1 h / 0 &deg;C<br /> <br /> &nbsp;