[NH:1]1[CH2:9][CH2:8][CH2:7][CH:3]([C:4]([OH:6])=[O:5])[CH2:2]1.[OH-].[Na+].[CH2:12]([O:19][C:20](Cl)=[O:21])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1>O.O1CCCC1>[CH2:12]([O:19][C:20]([N:1]1[CH2:9][CH2:8][CH2:7][CH:3]([C:4]([OH:6])=[O:5])[CH2:2]1)=[O:21])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1To an ice cooled solution of nipecotic acid (10.0 g, 77.5 mmol), sodium hydroxide (3.4 g, 85 mmol), and tetrahydrofuran (50 mL) in water (100 mL) was added by simultaneous dropwise addition benzylchloroformate (13.3 mL, 93 mmol) in tetrahydrofuran (50 mL) and sodium hydroxide (3.4 g, 85 mmol) in water (50 mL). Warmed slowly to room temperature. After 24 hours tetrahydrofuran was removed in vacuo and the resulting aqueous mixture acidified with 3 N hydrochloric acid and extracted with dichloromethane (3×). The combined organic portions were dried with anhydrous magnesium sulfate. Filtration followed by evaporation of the filtrate in vacuo gave the titled compound. 1HNMR (CHCl3, 300 MHz) □ 7.45-7.20 (m, 5H); 5.14 (m, 2H); 4.21 (br s, 1H); 3.96 (m, 1H), 3.15 (br s, 1H); 2.93 (m, 1H); 2.51 (m, 1H); 2.09 (m, 1H); 1.80-1.60 (m, 2H); 1.50 (m, 1H) ppm.
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