C([O:3][C:4]([C:6]1([C:11]2[CH:16]=[CH:15][C:14]([Br:17])=[CH:13][CH:12]=2)[O:10][CH2:9][CH2:8][O:7]1)=[O:5])C.O.[OH-].[Li+]>O1CCCC1>[Br:17][C:14]1[CH:13]=[CH:12][C:11]([C:6]2([C:4]([OH:5])=[O:3])[O:7][CH2:8][CH2:9][O:10]2)=[CH:16][CH:15]=1To a solution of 2-(4-Bromo-phenyl)-[1,3]dioxolane-2-carboxylic acid ethyl ester (example 346a), 300 mg) in tetrahydrofuran (2 mL) and water (2 mL) was added lithium hydroxide (41 mg) in two portions. The reaction mixture was stirred at room temperature over 2 days then concentrated in vacuo. The residue was acidified to pH=1 with aqueous hydrochloric acid solution (0.1N) extracted with ethyl acetate. The combined organic layer were washed with brine, dried over sodium sulfate, filtered and evaporated in vacuo to yield the title compound as a colorless oil (225 mg; 66%). MS (ESI): m/z=271.1 [M−H]−.
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