(2R)-2-Hexyloxirane → (alphaS,gammaR)-alpha-(4-butylphenyl)-gamma-hexyl-gamma-butyrolactone

Participants

Reaction Conditions

Reaction Steps

4-Butylphenylacetic acid (5 g) was dissolved in THF (100 ml), followed by cooling the solution down to -60° C., dropwise adding a tetrahydrofuran solution of LDA (10.4 mmol) over 30 minutes, raising the temperature up to 0° C., agitating for 30 minutes, cooling down to -60° C., dropwise adding a mixed solution of (R)-1,2-epoxyoctane (3.4 g) with anhydrous THF (5 ml) over 10 minutes, gradually raising the temperature, agitating at room temperature overnight, pouring the reaction solution in ice water (100 ml) and toluene (200 ml), washing the resulting organic layer with 6N--HCl, 2N--NaOH and saturated NaCl aqueous solution in this order, drying over anhydrous magnesium sulfate, concentrating the organic layer under reduced pressure, placing the resulting concentrate in a 1 l three-necked flask, adding toluene (250 ml) and p-toluenesulfonic acid (1.1 g), heating the mixture under reflux for 4 hours, dehydrating with a Dien-Stark type drain tube, adding ice water (100 ml), washing the organic layer with 6N--HCl, 2N--NaOH and saturated NaCl aqueous solution in this order, drying over magnesium sulfate, concentrating the organic layer under reduced pressure, separation-purifying according to chromatography and recrystallizing from ethanol to obtain (αS,γR)-α-(4-butylphenyl)-γ-hexyl-γ-butyrolactone (trans-form) (0.8 g). m.p.: 37.7° C.

Provenance & Evidence