Boron trifluoride etherate → HCID 15125097, compound

Reaction equation

[CH3:1][C:2]1[CH:7]=[C:6]([CH3:8])[C:5]([CH3:9])=[CH:4][C:3]=1[OH:10].[F:11][C:12]1[CH:17]=[CH:16][C:15]([CH:18](O)[CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][C:24]([OH:26])=[O:25])=[CH:14][CH:13]=1.B(F)(F)F.CCOCC>C1(C)C=CC=CC=1>[F:11][C:12]1[CH:13]=[CH:14][C:15]([CH:18]([C:4]2[C:5]([CH3:9])=[C:6]([CH3:8])[CH:7]=[C:2]([CH3:1])[C:3]=2[OH:10])[CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][C:24]([OH:26])=[O:25])=[CH:16][CH:17]=1

Participants

Procedure

To a solution of 2,4,5-trimethylphenol (2.0 mg) and 7-(4-fluorophenyl)-7-hydroxyheptanoic acid (3.5 g) in toluene (60 ml) was added boron trifluoride ethyl ether (0.56 ml) at 70° C. and the reaction was carried out at the same temperature for 6 hours. After cooling in air, the reaction mixture was extracted by addition of water and ethyl acetate. The organic layer was washed in turn with water and saturated saline and dried with anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. The residue was subjected to silica gel column chromatography and eluted with ethyl acetate/hexane (1 : 5) and the objective compound was recrystallized from ethyl acetate/hexane to obtain 7-(4-fluorophenyl)-7-(2-hydroxy-3,5,6-trimethylphenyl)heptanoic acid (4.5 g) (Compound 1). The physical properties and spectrum data thereof are shown in Tables 3 and 4.