Hydrochloric Acid → 3-Hydroxy-2-n-tetradecyl-11-icosenoic acid

Participants

Reaction Conditions

Reaction Steps

Diisopropyl amine (5.04 ml, 36.02 millimole) and dry tetrahydrofuran (30 ml) were introduced into a reaction vessel sufficiently substituted by argon gas. The reaction mixture was cooled to -78° C., and then 1.6M butyl lithium/hexane solution (23.64 ml, 37.82 millimole) was added dropwise thereto. The cooling bath was removed and the solution was allowed to warm to 0° C. and stirred for 30 minutes at the same temperature. The lithium diisopropylamide/tetrahydrofuran solution was again cooled to -78° C., and palmitic acid (4.62 g, 18.02 millimole) in dry tetrahydrofuran (60 ml) was added thereto, and the reaction mixture was stirred for 15 minutes at the same temperature (-78° C.). Then, the reaction temperature was raised to room temperature, and the reaction was continued for 1 hour. The reaction mixture was again cooled to -78° C., and 9-octadecenal (4 g, 15.02 millimole) in dry tetrahydrofuran (60 ml) was added dropwise thereto. The obtained mixture was reacted for 4 hours under the same conditions, and allowed to warm to 0° C., and the reaction was stopped by adding 1N hydrochloric acid (200 ml). The reaction mixture was extracted thrice with chloroform. The organic phase was washed twice with water and then dried over anhydrous sodium sulfate. The inorganic salt was filtered off and the solvent was distilled off from the filtrate. The obtained residue was dissolved in a developing solvent and fractionated through silicagel chromatography (n-hexane:ethyl acetate=8:2→chloroform:methanol=95:5) to give 3-hydroxy-2-n-tetradecyl-11-icosenoic acid (II)(3.73 g, yield 47.5%) in the form of white viscous solid.

Provenance & Evidence