[CH2:1]([Li])CCC.[C:6]([NH:16][C@H:17]([CH:25]=O)[CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)([O:8][CH2:9][C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1)=[O:7].[NH4+].[Cl-]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.O1CCCC1>[CH2:9]([O:8][C:6]([NH:16][CH:17]([CH:25]=[CH2:1])[CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)=[O:7])[C:10]1[CH:15]=[CH:14][CH:13]=[CH:12][CH:11]=1To a stirred suspension of methyltriphenylphosphonium bromide (10.72 g, 0.03 moles) in 100 mL of dry tetrahydofuran at −78° C. was added dropwise 1.6M n-butyl lithium (17.5 mL, 0.028 moles), and the mixture was stirred for 0.5 hrs at −78˜−20° C. Then was added a solution of N-Cbz-phenylalaninal (5.67 g, 0.02 moles) in 50 mL of dry tetrahydrofuran, and the mixture was stirred for 16 hrs at room temperature. After addition of saturated NH4Cl (50 mL) the mixture was extracted with EtOAc, and the extract was washed with water and brine. It was dried over Na2SO4 and evaporated to give an oily residue. The crude product was purified by column chromatograpy on silica gel with elution by 5:95 EtOAc-hexane to give pure 2-benzyloxycarbonylamino-1-phenyl-3-butene.
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