[CH2:1]([O:3][CH:4]([O:20][CH2:21][CH3:22])[CH2:5][N:6]1[C:14]2[CH2:13][CH2:12][CH2:11][CH2:10][C:9]=2[CH:8]=[C:7]1[C:15]([O:17]CC)=[O:16])[CH3:2].C(O)C.O1CCCC1.[OH-].[Na+]>O>[CH2:21]([O:20][CH:4]([O:3][CH2:1][CH3:2])[CH2:5][N:6]1[C:14]2[CH2:13][CH2:12][CH2:11][CH2:10][C:9]=2[CH:8]=[C:7]1[C:15]([OH:17])=[O:16])[CH3:22]
To a mixture of 195b (4.7 g, 15.2 mmol) in a mixed solvent of ethanol (20 mL), tetrahydrofuran (20 mL), and water (30 mL) was added sodium hydroxide (3.0 g, 75.0 mmol). The reaction was heated at 75° C. for two days and concentrated under reduced pressure. The residue was suspended in water and neutralized with diluted aqueous citric acid solution. The mixture was extracted with ethyl acetate (3×100 mL) and the combined organic phase was concentrated under reduced pressure to afford 195c (3.32 g, 78%). MS-ESI: [M-EtOH+H]+ 236.
Wird geladen…
