Water → 4-[(4,4-Dimethylcyclohexylidene)-(4-hydroxy-phenyl)-methyl]-benzoic acid methyl ester

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Reaction Steps

To a slurry of zinc powder (0.26 g, 4.01 mmol) in dry tetrahydrofuran (9 mL) was slowly added titanium tetrachloride (0.21 mL, 1.95 mmol). The reaction mixture was heated at reflux for 2.5 h, then a solution of 4,4-dimethyl-cyclohexanone (0.2 g, 1.58 mmol) and 4-(4-hydroxy-benzoyl)-benzoic acid methyl ester (24) (0.135 g, 0.53 mmol) in dry tetrahydrofuran (9 mL) was added. The reaction mixture was heated at reflux for 2 h. The reaction mixture was cooled to room temperature, water (5 mL) was added followed by 10% K2CO3 (5 mL). The reaction mixture was filtered through a pad of Celite and the pad washed with EtOAc. The filtrate was transferred to a separatory funnel and the layers were separated. The aqueous layer was extracted with EtOAc and the combined organic layers were washed with brine, dried over Na2SO4, filtered and concentrated. The crude material was loaded onto silica and purified by flash chromatography with a hexanes:EtOAc gradient (100:0 to 80:20) to give 0.162 g (88%) of the title compound 171 as an oil. 1H NMR (400 MHz, DMSO-d6): δ 0.93 (s, 6 H), 1.31-1.33 (m, 4 H), 2.12-2.19 (m, 4 H), 3.81 (s, 3 H), 6.66 (d, J=8.4 Hz, 2 H), 6.84 (d, J=8.6 Hz, 2 H), 7.18 (d, J=8.3 Hz, 2 H), 7.86 (d, J=8.3 Hz, 2 H), 9.36 (s, 1 H).

Provenance & Evidence