Sulfuric Acid → 16-(p-Methylthiophenoxy)-hexadeca-5,8,11,14-tetraynoic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

12.03 ml (6.077 g, 0.0455 mol) of 3.8N ethylmagnesium bromide in ether was added dropwise to a solution of 9.65 g (0.0379 mol) of 9-(p-methylthiophenoxy)-1,4,7-nonatriyne in 80 ml of anhydrous tetrahydrofuran. The temperature was maintained at -10° C. The reaction mixture was stirred for 1 hour further at 0° C., allowed to warm to room temperature, and then 374 mg of cuprous cyanide were added. The mixture was stirred for 20 additional minutes, heated to 40° C. and then treated with 13.83 g (49.38 mmol) of 7-iodo-5-heptynoic acid ethyl ester in 30 ml of anhydrous tetrahydrofuran.The resulting mixture was stirred for 3 additional hours at 40° C., then poured on to 300 ml of 1N sulfuric acid and ice. After extraction with ether (3×150 ml), the combined extract was concentrated to a small volume and washed several times with Versene solution and water, dried and evaporated in vacuo. The crude material was purified by column chromatography on 125 g of silica gel, using hexane:ethyl acetate (95:5) as eluant, to obtain 16-(p-methylthiophenoxy)-hexadeca-5,8,11,14-tetraynoic acid ethyl ester, as an oil. The product was stored in dry ice.

Provenance & Evidence