Trifluoroacetic acid → 2,2,4,4-Tetramethyl-chroman-6-carboxylic acid 4-(carboxymethyl)phenyl ester
Reaktionsgleichung
C([O:5][C:6]([CH2:8][C:9]1[CH:14]=[CH:13][C:12]([O:15][C:16]([C:18]2[CH:19]=[C:20]3[C:25](=[CH:26][CH:27]=2)[O:24][C:23]([CH3:29])([CH3:28])[CH2:22][C:21]3([CH3:31])[CH3:30])=[O:17])=[CH:11][CH:10]=1)=[O:7])(C)(C)C.FC(F)(F)C(O)=O>>[C:6]([CH2:8][C:9]1[CH:10]=[CH:11][C:12]([O:15][C:16]([C:18]2[CH:19]=[C:20]3[C:25](=[CH:26][CH:27]=2)[O:24][C:23]([CH3:29])([CH3:28])[CH2:22][C:21]3([CH3:31])[CH3:30])=[O:17])=[CH:13][CH:14]=1)([OH:7])=[O:5]Komponenten
3
Versuchsvorschrift
A solution of 2,2,4,4-tetramethyl-chroman-6-carboxylic acid 4-(tert-butoxycarbonylmethyl)phenyl ester (Compound 45, 0.1 g, 0.23 mmol) was treated with 5 mL of trifluoroacetic acid and stirred at ambient temperature for 1 h. The trifluoroacetic acid was distilled off under reduced pressure and the residue was subjected to preparative reverse phase HPLC using 10% water in acetonitrile as the mobile phase to afford the title compound as a white solid (0.045 g, 50%).