C[O:2][C:3](=[O:19])[CH2:4][C:5]1([CH3:18])[C:10]2[CH2:11][C:12]3[CH:13]=[CH:14][CH:15]=[CH:16][C:17]=3[C:9]=2[CH2:8][CH2:7][O:6]1.[OH-].[Na+]>CO.O>[CH3:18][C:5]1([CH2:4][C:3]([OH:19])=[O:2])[C:10]2[CH2:11][C:12]3[CH:13]=[CH:14][CH:15]=[CH:16][C:17]=3[C:9]=2[CH2:8][CH2:7][O:6]1Hydrolysis of this ester to the title compound is effected as follows: The latter ester (11.5 g) is dissolved in 400 ml of methanol and the solution mixed with a solution of 12 g of sodium hydroxide in 100 ml of water. The resulting mixture is kept at room temperature overnight. Methanol is removed by evaporation. The residue is diluted with water. The aqueous solution is extracted repeatedly with ether, and acidified with 6N hydrochloric acid. The resulting precipitate is extracted with ether. The ether extract is dried (MgSO4), filtered and concentrated. The residue is crystallized from benzene to give the title compound, m.p. 179°-180° C, nmr (CDCl3) δ 1.45 (s, 3H), 2.51 (m, 2H), 2.73 (s, 2H), 3.25 (t, 2H), 4.02 (t, 2H), 7.26 (m, 4H), 9.80 (broad, 1H).
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