反应详情

26-1 (9.20 g) was dissolved in 90 ml of THF, adding 50 ml of H2O, followed by 21 ml of 2.0N LiOH in portions over a period of 2 hr. The solution was let stir 20 hr and the reaction was worked up by addition of dil. KHSO4 to neutrality, evacuation of solvent under reduced pressure to give a thick paste to which was added 200 ml of H2O in portions with stirring, followed by dil. KHSO4 to acidity (pH<2). After stirring for 1 hr, the solid was isolated by filtration, washing with H2O twice, and drying in vacuo to give 6.45 g (72% yield overall) of intermediary Boc-D-cyclohexylglycine-proline. Evaporation of the filtrate to a volume of <100 ml afforded 26-2.

1. customto give a thick paste to which
2. stirringwith stirring
3. stirringAfter stirring for 1 hr
4. customthe solid was isolated by filtration
5. washwashing with H2O twice
6. customdrying in vacuo