反应详情

Anhydrous HCl was bubbled through a stirred suspension of trans-4-hydroxy-L-proline (80 g, 0.61 mol) in 500 ml anhydrous methanol until the mixture was homogeneous. The reaction was heated to reflux for five hours, and the volume of the solvent then reduced by one half. Ether (100 ml) was added, and the mixture kept in a freezer overnight. The resulting precipitate was filtered, washed with ether and dried under reduced pressure to yield 111 g of present title product (93% yield). mp 170°-172° C.

1. temperatureThe reaction was heated
2. temperatureto reflux for five hours
3. filtrationThe resulting precipitate was filtered
4. washwashed with ether
5. customdried under reduced pressure