lithium hydroxide in tetrahydrofuran; water T=0 - 25°C; Yield given. Yields of byproduct given;

<b>Multi-step reaction with 2 steps<br /> </b>1.1: acetic anhydride / 1.5 h / 0 - 60 &deg;C / Inert atmosphere<br />1.2: 1 h / 0 - 20 &deg;C / Inert atmosphere<br />2.1: triethylamine / dichloromethane / 14 h / Inert atmosphere; Reflux<br /> <br /> &nbsp;