Cyclooctanone → Methyl 4-[cyclooctylidene(4-hydroxyphenyl)methyl]benzoate

Participants

Reaction Steps

To a 3-neck round-bottomed flask was added zinc powder (0.40 g, 6.12 mmoL) followed by anhydrous THF (15 mL). To the stirred suspension was slowly added TiCl4 (0.32 mL, 0.55 g, 2.9 mmoL) at RT under a nitrogen atmosphere. The reaction mixture was heated at reflux for 2 h. To the reaction mixture was added a solution of methyl 4-[(4-hydroxyphenyl)carbonyl]benzoate (24) (0.193 g, 0.75 mmoL) and cyclooctanone (0.31 g, 2.46 mmoL) in anhydrous THF (5 mL). The reaction mixture was heated at reflux under a nitrogen atmosphere to 2 h. The oil bath was removed and the reaction mixture was allowed to cool at RT. To the reaction mixture was added H2O (5 mL) followed by 10% K2CO3 (5 mL). The reaction mixture was filtered through a pad of Celite with the aid of H2O and EtOAc. The filtrate was transferred to a separatory funnel and the layers were separated. The organic phase was dried (MgSO4), filtered, and the filtrate was concentrated to give a yellow oil. The crude product was purified by flash chromatography on silica gel with a CH2Cl2:MeOH gradient (100:0 to 95:5) to give 0.159 g (60%) of compound 158 as an oil. 1H NMR (400 MHz, DMSO-d6): δ 1.36-1.54 (m, 8H), 1.59 (m, 2H), 2.14 (m, 2H), 2.20 (m, 2H), 3.80 (s, 3H), 6.67 (d, J=8.3 Hz, 2H), 6.93 (d, J=8.3 Hz, 2H), 7.26 (d, J=8.1 Hz, 2H), 7.87 (d, J=8.1 Hz, 2H), 9.30 (s, 1H).

Provenance & Evidence