1-Cyclohexenyl trifluoromethanesulfonate → 4-Cyclohex-1-en-1-yl-benzoic acid ethyl ester

Participants

Reaction Steps

Cyclohexen-1-yl trifluoromethanesulfonate (1.00 g, 4.34 mmol), lithium chloride (0.551 g, 13.0 mmol) and tris-dibenzylideneacetone di-palladium (0) (79.5 mg, 0.0868 mmol) were combined in anhydrous N-methylpyrrolidinone (20 mL) and the resulting solution deoxygenated by sparging with nitrogen for 30 minutes. To the catalyst solution was added a solution of 4-(tri-n-butyl-stannyl)-benzoic acid ethyl ester of Step A (2.10 g, 4.77 mmol) in anhydrous N-methylpyrrolidinone (9 mL). The reaction was stirred at room temperature for 38 hours, followed by addition of 1 M potassium fluoride (5 mL). After stirring for 3 hours, the reaction mixture was diluted with ethyl acetate (200 mL) and filtered through celite. The filtrate was washed with 1 M potassium fluoride, water and brine. The organic phase was dried over anhydrous magnesium sulfate, filtered and concentrated. The residue was purified by flash column chromatography on silica gel, eluting with a solvent gradient of from 0 to 10% ethyl acetate in hexane. A solid was isolated which was recrystallized from pentane (−20° C.) to afford the title compound (0.608 g) as a white solid, m.p. 66° C.

Provenance & Evidence