Water → E 5090

Reaction equation

[CH2:1]([C:3]1[CH:12]=[CH:11][CH:10]=[C:9]2[C:4]=1[C:5]([OH:21])=[C:6]([O:19][CH3:20])[CH:7]=[C:8]2/[CH:13]=[C:14](\[CH3:18])/[C:15]([OH:17])=[O:16])[CH3:2].[C:22](OC(=O)C)(=[O:24])[CH3:23].O>N1C=CC=CC=1>[C:22]([O:21][C:5]1[C:4]2[C:9](=[CH:10][CH:11]=[CH:12][C:3]=2[CH2:1][CH3:2])[C:8](/[CH:13]=[C:14](/[CH3:18])\[C:15]([OH:17])=[O:16])=[CH:7][C:6]=1[O:19][CH3:20])(=[O:24])[CH3:23]

Participants

Procedure

440 mg of (E)-3-(5-ethyl-4-hydroxy-3-methoxy-1-naphthyl)-2-methylpropenoic acid was dissolved in 2.4 ml of pyridine and 0.42 ml of acetic anhydride was added, followed by stirring at room temperature for 1 hour. The reaction mixture was poured into water and extracted with ethyl acetate. The organic layer was washed with dilute hydrochloric acid and water in this order, dried over anhydrous magnesium sulfate and concentrated in vacuo. The resultant crystals were washed with hexane to obtain 390 mg of the titled compound as colorless crystals.