Sulfuric Acid → 16-Phenylthiohexadeca-5,8,11,14-tetraynoic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

8.4 ml (4.254 g, 31 mmol) of 3.79N ethereal ethylmagnesium bromide was added dropwise, under argon to a solution of 6.5 g (29 mmol) of 9-phenylthio-1,4,7-nonatriyne in 20 ml of anhydrous tetrahydrofuran. The temperature was maintained at -25° C. After the addition, the reaction mixture was stirred for 1 hour further at the same temperature and then 285 mg of cuprous cyanide were added. After the addition, the mixture was stirred for 20 minutes more at 0° C. and then treated with 12.2 g (44 mmol) of 7-iodo-5-heptynoic acid ethyl ester in 15 ml of anhydrous tetrahydrofuran. After the addition, the solution was stirred for an additional 3 hours at room temperature. The reaction mixture was then poured into 150 ml of 1N sulfuric acid and ice and the product extracted with ether (3×150 ml). The combined organic extract was concentrated to about 1/3 its original volume and washed 3 times with EDTAand water, dried over sodium sulfate and evaporated in vacuo. The crude material was purified by column chromatography on 100 g of silica gel, using hexane-ethyl acetate (95:5) as eluant, to obtain 16-phenylthiohexadeca-5,8,11,14-tetraynoic acid ethyl ester, as an oil. The product was stored in dry ice.

Provenance & Evidence