C([Li])(C)(C)C.Br[C:7]1[CH:12]=[CH:11][C:10]([Br:13])=[CH:9][CH:8]=1.[Cu](C#N)C#N.[C:19]([O:24][CH3:25])(=[O:23])[C@H:20]1[O:22][CH2:21]1.[Cl-].[NH4+]>CCCCC>[Br:13][C:10]1[CH:11]=[CH:12][C:7]([CH2:21][C@H:20]([OH:22])[C:19]([O:24][CH3:25])=[O:23])=[CH:8][CH:9]=1100 ml (170 mmol) of a 1.7 M solution of tert-butyllithium in pentane are added dropwise to a solution of 48 g (204 mmol) of 1,4-dibromobenzene in 160 ml of tert-butyl dimethyl ether, cooled to −30° C., followed by addition of 7.3 g (82 mmol) of copper cyanide. The reaction medium is stirred for 15 minutes and a solution of 6 ml (68 mmol) of (S)-methyl glycidate in 10 ml of tert-butyl dimethyl ether is then added. After stirring for 20 minutes at −30° C., the reaction medium is hydrolysed with 150 ml of saturated aqueous ammonium chloride solution and extracted with ethyl acetate. The organic phase is washed with saturated aqueous sodium chloride solution, dried over magnesium sulfate, filtered and evaporated. The residue obtained is purified by chromatography on a column of silica eluted with heptane, and the polarity is then increased up to a 6/4 heptane/ethyl acetate mixture. 23.5 g (44%) of methyl 3-(4-bromophenyl)-2(S)-hydroxypropanoate are obtained.
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