Formic Acid → 3-Cyclopentyl-2-(4-methanesulfonyl-phenyl)-acrylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of the isomeric mixture of 3-cyclopentyl-2-(4-methylsulfanyl-phenyl)-acrylic acid ethyl ester [58.93 g, 0.203 mol, (E):(Z)=1.44:1] in formic acid (203 mL) was cooled to 0° C. and then slowly treated with a 30% aqueous hydrogen peroxide solution (62.2 mL, 0.609 mol). The reaction mixture was stirred at 0° C. for 30 min then allowed to warm to 25° C. where it was stirred for 2 h. The reaction mixture was cooled back to 0° C. and then slowly treated with a saturated aqueous sodium bisulfite solution (1 L). The reaction mixture was then extracted with ethyl acetate (2×700 mL). The combined organic layers were washed with a saturated aqueous sodium chloride solution (1×700 mL), dried over magnesium sulfate, filtered, and concentrated in vacuo to afford 3-cyclopentyl-2-(4-methanesulfonyl-phenyl)-acrylic acid ethyl ester (65.02 g, 99%) as a yellow oil consisting of a 1.63:1 mixture of (E):(Z) isomers. The material was used without further purification and characterization.

Provenance & Evidence