反应详情

Acid 2-1b (13.20 g, 54.1 mmol) was suspended in 500 mL EtOH, p-TsOH--H2O (11.3 g, 59 mmol) was added and the mixture was heated at reflux overnight. After distilling off the solvent, fresh EtOH was added and distilled off, then more EtOH was added and the mixture was distilled to 100 mL at which point 800 mL ether was added. After cooling to 4°, solvent was decanted from the gum which was rinsed with additional ether, and dried, providing 35-2 as a hygroscopic glass. Additional 35-2 was recovered from the solvent phase by concentration and triturating with ether (2×).

1. temperaturethe mixture was heated
2. temperatureat reflux overnight
3. distillationAfter distilling off the solvent, fresh EtOH
4. additionwas added
5. distillationdistilled off
6. additionmore EtOH was added
7. distillationthe mixture was distilled to 100 mL at which
8. additionwas added
9. temperatureAfter cooling to 4°
10. customsolvent was decanted from the gum which
11. washwas rinsed with additional ether
12. customdried