Lithium diisopropylamide → 2-[2-(4-Chloro-phenyl)-5-methyl-thiazol-4-yl]-3-methoxy-5-[1-(tetrahydro-pyran-4-yl)-meth-(E)-ylidene]-cyclopent-2-enone

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-[2-(4-Chloro-phenyl)-5-methyl-thiazol-4-yl]-3-methoxy-cyclopent-2-enone (640 mg, 2 mmol) in anhydrous tetrahydrofuran (12 ml) at −78° C. under an atmosphere of nitrogen was added lithium diisopropylamide (1.8M in THF/heptanes/ethylbenzene; 1.1 ml, 2 mmol) dropwise over a period of 5 minutes, and the reaction allowed to stir at 78° C. for 30 minutes. A solution of tetrahydro-pyran-4-carbaldehyde (228 mg, 2 mmol) in anhydrous tetrahydrofuran (1 ml) was then added dropwise over a period of 5 minutes before the reaction is allowed to warm to room temperature and stirred for a further 30 minutes. Potassium tert-butoxide (337 mg, 3 mmol) was then added in one portion and the reaction stirred for a further 90 minutes. The reaction was quenched by the addition of saturated aqueous ammonium chloride solution (50 ml) and extracted with ethyl acetate (50 ml) and the organic later separated, dry loaded onto silica and purified by flash chromatography to give 2-[2-(4-Chloro-phenyl)-5-methyl-thiazol-4-yl]-3-methoxy-5-[1-(tetrahydro-pyran-4-yl)-meth-(E)-ylidene]-cyclopent-2-enone (195 mg).

Provenance & Evidence