Tetrahydrofuran → Boc-Leu-Pro-OBn

Reaction equation

C1COCC1.[NH:6]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[C@H:7]([C:12]([OH:14])=O)[CH2:8][CH:9]([CH3:11])[CH3:10].O.[NH:23]1[CH2:37][CH2:36][CH2:35][C@H:24]1[C:25]([O:27][CH2:28][C:29]1[CH:34]=[CH:33][CH:32]=[CH:31][CH:30]=1)=[O:26]>CN(C=O)C>[NH:6]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[C@H:7]([C:12]([N:23]1[CH2:37][CH2:36][CH2:35][C@H:24]1[C:25]([O:27][CH2:28][C:29]1[CH:30]=[CH:31][CH:32]=[CH:33][CH:34]=1)=[O:26])=[O:14])[CH2:8][CH:9]([CH3:10])[CH3:11]

Participants

Procedure

THF (300 ml) was added to BOC-Leu-OH.H2O (149.59 g, 0.6 M). THF (150 ml) and DMF (100 ml) were added thereto to prepare a solution. Then H-Pro-OBzl (152.28 g, 0.63 M) was added thereto, and WSCI (120.8 ml, 0.66 M) was added dropwise at -10° C., and further DMF (100 ml) was added; then the mixture was stirred at room temperature overnight. After distilling off the solvent in vacuo, ethyl acetate (600 ml) was added to the residue, which was then washed three times with 5% aqueous sodium bicarbonate, twice with 1 N HCl and twice with water. The ethyl acetate layer was dried with anhydrous sodium sulfate and concentrated in vacuo. The resultant oily material was dissolved in benzene (1 l.) and concentrated in vacuo to obtain an oily substance [1].