[CH2:1]([N:4]([CH2:8][C:9]1[S:13][C:12]([S:14]([N:17]2[CH2:22][CH2:21][CH:20]([C:23](N(OC)C)=[O:24])[CH2:19][CH2:18]2)(=[O:16])=[O:15])=[CH:11][CH:10]=1)[CH2:5][CH:6]=[CH2:7])[CH:2]=[CH2:3].[CH2:29]([Li])[CH2:30][CH2:31][CH2:32][CH2:33][CH3:34].Cl.CCO>C1COCC1>[CH2:1]([N:4]([CH2:8][C:9]1[S:13][C:12]([S:14]([N:17]2[CH2:18][CH2:19][CH:20]([C:23](=[O:24])[CH2:29][CH2:30][CH2:31][CH2:32][CH2:33][CH3:34])[CH2:21][CH2:22]2)(=[O:16])=[O:15])=[CH:11][CH:10]=1)[CH2:5][CH:6]=[CH2:7])[CH:2]=[CH2:3]327b (376 mg, 0.88 mmol) was dissolved in anhydrous THF and cooled to −20° C. To this solution was added dropwise at −20° C. hexyllithium (2M in hexane) (2.46 mL, 6.2 mmol). The reaction was allowed to warm to rt. during 3 h and poured on 100 mL HCl/EtOH (5%). The aqueous phase was extracted with CH2Cl2 and the combined organic layers are washed with NaOH (2N) and brine, dried over MgSO4 and evaporated to dryness. The crude material was purified by flash chromatography on silica gel using cyclohexane/EtOAc 4:1 as eluent to obtain 186 mg (47%) of (327c) as a brownish oil: H1 NMR (CDCl3) δ 7.40 (d, J=3.6 Hz, 1H), 725 (d, J=3.6 1H), 5.95 (m, 2H), 5.50 (m, 4H), 4.32 (s, 2H), 3.70-3.50 (m, 6H), 2.50 (m, 2H), 2.32 (m, 3H), 1.85 (m, 2H), 1.68 (m, 2H), 1.46 (m, 2H), 0.130-1.12 (m, 6H), 0.80 (t, J=6.6 Hz, 3H), M/Z APCI: 453.2 (M+1)
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