Tetrahydrofuran → (2S)-2-methylhexanoic acid >90%ee

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 10 ml Schlenk tube, 5.0 mg of dry zinc chloride was dissolved in 3.0 ml of absolute tetrahydrofuran and cooled to 0° C. under argon. Thereafter, 222 mg of (S)-2-trifluoromethanesulfonyloxypropionic acid (ee 99%) and 1.05 ml of n-butylmagnesium chloride (2.00 M solution in THF) were added in succession and the reaction was stirred for 3 h at 0° C. Thereafter, the reaction mixture was diluted with petroleum ether, saturated sodium carbonate solution was added and the organic phase was separated off. The aqueous phase was acidified with an aqueous 2 M HCl solution, saturated with NaCl and extracted 3 times with 10 ml of diethyl ether. The combined organic phases were dried over MgSO4 and concentrated in vacuo. Pure (S)-2-methylhexanoic acid (ee 99%) was obtained in 92% yield.

Herkunft & Nachweise