[F:1][C:2]1[CH:3]=[C:4]([S:9]([N:12]([CH2:20][CH3:21])[C@@H:13]([CH2:18]O)[C:14]([O:16]C)=[O:15])(=[O:11])=[O:10])[CH:5]=[CH:6][C:7]=1[F:8].[OH-].[Na+]>O1CCOCC1>[CH2:20]([N:12]([S:9]([C:4]1[CH:5]=[CH:6][C:7]([F:8])=[C:2]([F:1])[CH:3]=1)(=[O:10])=[O:11])[C:13](=[CH2:18])[C:14]([OH:16])=[O:15])[CH3:21]A solution of 3G (2.8 g, 7.9 mmol) in dioxane (30 mL) was added with 20% NaOH aq. solution (20 mL) and the mixture heated at 80° C. for 5 h. The organic solvent was removed under reduced pressure and the aqueous phase acidified with 10% HCl and extracted with CH2Cl2 (3×30 mL). The recombined organic phases were anhydrified using Na2SO4, evaporated under reduced pressure and then the resulting residue purified by flash chromatography (100% EtOAc) to obtain 4G as white solid (1 g, 44% yield). 1HNMR (DMSO, 200 MHz) δ 1.07 (t, 3H), 3.42 (q, 2H), 5.78 (s, 1H), 6.36 (s, 1H), 7.67 (m, 2H), 7.87 (m, 1H), 13.02 (bs, 1H).
Wird geladen…
