[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C@H:8]2[CH2:13][CH2:12][C@H:11]([C:14](OC)=[O:15])[CH2:10][CH2:9]2)=[CH:4][CH:3]=1.[H-].C([Al+]CC(C)C)C(C)C.CO.Cl>ClCCl>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([C@H:8]2[CH2:9][CH2:10][C@H:11]([CH:14]=[O:15])[CH2:12][CH2:13]2)=[CH:6][CH:7]=1To a stirred solution of methyl trans-4-(4-chlorophenyl)cyclohexanecarboxylate (compound of formula (VIIa)) (25.3 g, 100 mmol) in dichloromethane (250 mL) at −78° C. under argon was added a 1M solution of diisobutylaluminium hydride (DIBAL) in dichloromethane (110 mL, 110 mmol) and the mixture was stirred for 90 minutes. A further 5 mLs of DIBAL was then added. Methanol (125 mL) was added with stirring and the mixture allowed to warm to −10° C. 1M aqueous hydrochloric acid (250 mL, 250 mmol) was then added with stirring. The aqueous layer was extracted with dichloromethane (250 mL) and the combined organics washed twice with water (2×125 mL). The organics were concentrated under vacuum to a volume of 75 mL, the residue was diluted by the addition ethyl acetate (125 mL) and the mixture was then concentrated under vacuum to a volume of 75 mL. The resulting mixture containing the title compound was used in the next step without analysis or purification.
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