反应详情

A mixture of NaOAc (16.3 g, 0.20 mol) and 4-hydroxy-4-(1-carboxy-1-phenyl-methyl)piperidine-1-carboxylic acid tert-butyl ester (33.3 g, 0.099 mol) were dissolved in Ac2O (110 mL) in a sealed tube and allowed to stir at rt for 4 h. The mixture was then heated at 70° C. for 16 h, after which the volatiles were removed in vacuo. The residue was subsequently diluted with EtOAc and 300 mL of 1M NaOH was added. This mixture was stirred for 2 h and then the pH was adjusted to 2 using conc. HCl. The mixture was extracted with EtOAc (×3) and the combined organic layers were washed (brine), dried (Na2SO4) and evaporated to give an oil, which was triturated with hexane to give the title compound (28.9 g, 87%) as a colorless solid:

1. temperatureThe mixture was then heated at 70° C. for 16 h
2. customafter which the volatiles were removed in vacuo
3. additionThe residue was subsequently diluted with EtOAc and 300 mL of 1M NaOH
4. additionwas added
5. stirringThis mixture was stirred for 2 h
6. extractionThe mixture was extracted with EtOAc (×3)
7. washthe combined organic layers were washed (brine)
8. dry with materialdried (Na2SO4)
9. customevaporated
10. customto give an oil, which
11. customwas triturated with hexane