[CH:1]1([O:6][C:7]2[CH:8]=[C:9]([CH:15]([C:20]#[C:21][C:22]3[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=3)[CH2:16][C:17]([OH:19])=[O:18])[CH:10]=[CH:11][C:12]=2[O:13][CH3:14])[CH2:5][CH2:4][CH2:3][CH2:2]1.[CH3:28][CH2:29]O>OS(O)(=O)=O>[CH2:28]([O:18][C:17](=[O:19])[CH2:16][CH:15]([C:9]1[CH:10]=[CH:11][C:12]([O:13][CH3:14])=[C:7]([O:6][CH:1]2[CH2:5][CH2:4][CH2:3][CH2:2]2)[CH:8]=1)[C:20]#[C:21][C:22]1[CH:23]=[CH:24][CH:25]=[CH:26][CH:27]=1)[CH3:29]A solution of (+/-)-3-(3-cyclopentyloxy-4-methoxyphenyl)-3-phenylethynylpropionic acid (250 mg, 0.69 mmol) in EtOH (20 ml) and H2SO4 (1 drop) was refluxed for 6 hr. The solvent was evaporated, the residue taken up in Et2O, washed with aqueous Na2CO3, dried, and the solvent evaporated. The residue was crystallized from hexane, and gave the titled compound, 180 mg (67%). 1H NMR (400 MHz, CDCl3) δ 7.40 (m, 2 H), 7.28 (m, 3 H), 6.98 (m, 2 H), 6.82 (d, 1 H), 4.80 (m, 1 H), 4.32 (t, 1 H), 4.14 (q, 2 H), 3.80 (s, 3 H), 2.86 (d of d, 1 H), 2.76 (d of d, 1 H), 1.76-1.98 (m, 6 H), 1.62 (m, 2 H), 1.22 (t, 3 H).
Wird geladen…