Ammonium Chloride → 5-Cyclopent-1-en-1-yl-7-isopropyl-2,2-dimethyl-4-oxochroman-6-carbaldehyde

Participants

Reaction Steps

A solution of 550 mg (1.39 mmol) of 6-formyl-7-isopropyl-2,2-dimethyl-4-oxo-3,4-dihydro-2H-chromen-5-yl trifluoromethanesulfonate (Example 19A), 202 mg (1.81 mmol) of cyclopent-1-en-1-ylboronic acid, 112 mg (100 μmol) of tetrakis(triphenylphosphine)palladium and 503 mg (2.37 mmol) of potassium phosphate in 8 ml of degassed dioxane and stirred at 100° C. overnight. After cooling to room temperature, ammonium chloride solution is added and the mixture is extracted twice with ethyl acetate. The combined organic phases are dried over sodium sulfate, the solvent is then removed under reduced pressure and the residue is purified by column chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 20:1).

Provenance & Evidence