C[O:2][C:3](=[O:27])[CH2:4][C:5]1([CH2:25][CH3:26])[C:10]2[NH:11][C:12]3[C:17]([C:9]=2[CH:8]([CH2:18][C:19]2[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=2)[CH2:7][O:6]1)=[CH:16][CH:15]=[CH:14][CH:13]=3.[OH-].[Na+]>C(O)C>[CH2:18]([CH:8]1[C:9]2[C:17]3[C:12](=[CH:13][CH:14]=[CH:15][CH:16]=3)[NH:11][C:10]=2[C:5]([CH2:25][CH3:26])([CH2:4][C:3]([OH:27])=[O:2])[O:6][CH2:7]1)[C:19]1[CH:20]=[CH:21][CH:22]=[CH:23][CH:24]=1To a solution of 4-benzyl-1-ethyl-1,3,4,9-tetrahydropyrano[3,4-b]indole-1-acetic acid methyl ester (0.67 g, 1.8 mmol) in 30 mL of ethanol was added 30 mL of 10% solution of sodium hydroxide and heated at reflux for 2 hours under nitrogen. The reaction mixture was then cooled and concentrated in vacuo, diluted with 20 mL of H2O and extracted with ether. The aqueous layer was then acidified with 2N HCl and extracted with chloroform (3×100 mL), dried over magnesium sulfate and concentrated in vacuo to give 0.516 g (80%) of the product, m.p. 142°-143° C.
Loading…