Formylcycloheptane → 5-(Cycloheptyl-hydroxy-methyl)-3-methoxy-2-(2,4,6-trimethyl-phenyl)-cyclopent-2-enone

Participants

Reaction Steps

To a stirred solution of 3-methoxy-2-(2,4,6-trimethyl-phenyl)-cyclopent-2-enone (0.46 g, 2.0 mmol) in anhydrous THF (20 ml) at −78 C under an N2 atmosphere was added dropwise a solution of lithium diisopropylamide (1.22 ml of a 1.8M solution in THF/heptanes/ethyl benzene, 2.2 mmol). The reaction was stirred at −78 C for 90 minutes and then a solution of cycloheptanecarbaldehyde (316 mg, 2.5 mmol) in anhydrous THF (3 ml) was added dropwise. The reaction was stirred at −78 C for a further 30 minutes and then allowed to warm to room temperature over 30 minutes. The reaction was quenched by addition of H2O (25 ml) and extracted with EtOAc (3×20 ml). The combined organic extracts were washed with brine (15 ml), dried over MgSO4, filtered and evaporated to dryness under reduced pressure to give a brown oil (628 mg). The crude material was purified by flash chromatography over SiO2 using a 100% isohexane to 100% EtOAc gradient to give the desired product as a colourless oil (101 mg).

Provenance & Evidence