C([C@H]1COC(=O)N1[C:14](=[O:27])[C@H:15]([C:19]1[CH:24]=[CH:23][C:22]([Cl:25])=[C:21]([Cl:26])[CH:20]=1)[CH2:16][CH:17]=[CH2:18])C1C=CC=CC=1.[H-].[Al+3].[Li+].[H-].[H-].[H-].O.[OH-].[Na+]>O1CCCC1>[Cl:26][C:21]1[CH:20]=[C:19]([C@@H:15]([CH2:14][OH:27])[CH2:16][CH:17]=[CH2:18])[CH:24]=[CH:23][C:22]=1[Cl:25]4(S)-Benzyl-3-(2(S)-(3,4-dichlorophenyl)pent-4-en-1-oyl)oxazolidin-2-one (30.32 g) (see Bioorganic and Medicinal Chemistry Letters, 3, 319, (1993)) was dissolved in if anhydrous tetrahydrofuran (400 ml), cooled in an ice-bath and lithium aluminium hydride (5.7 g) carefully added in two portions (exothermic reaction). The mixture was stirred at 0° C. for 20 minutes and then stirred at room temperature for 1 hour before being cooled to 0° C. Water (6 ml) was carefully added followed by 2N aqueous sodium hydroxide solution (6 ml) and fixrther water (12 ml). The mixture was stirred vigourously for 40 minutes and the resulting precipitate removed by filtration and washed with diethyl ether. The filtrate was collected and the organic and aqueous phases separated. The solvent was then removed from the organic phase under reduced pressure to give a yellow oil which was chromatographed on silica gel eluting with a solvent gradient of 4:1 changing to 4:0, by volume, dichloromethane:hexane to give 4(S)-(3,4-dichlorophenyl)-5-hydroxypent-1-ene (11.74 g) as an oil.
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