Sodium Hydroxide → 5-[[5-(3-Ethyl-3-methyloxiranyl)-3-methyl-2-pentenyl]oxy]-1,3-benzodioxole

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Reaction Conditions

Reaction Steps

Into a 2 l., four-necked flask (with stirrer, thermometer, CaCl2 -tube and stopper) is placed a solution of 162 g. of the 3,7-dimethyl-1-(3,4-methylenedioxyphenoxy)-2,6-nonadiene in 1.1 l. of methylene chloride. The flask is immersed in an ice-salt bath (-5°C.). When the vigorously stirred solution is cooled to 0°C., 125 g. of pulverized 85% m-chloroperbenzoic acid is added in ca 5 g. portions at such a rate to keep the reaction temperature at 1°-3° (2 hours). After complete addition, the white suspension is stirred for 2 hours, at 0°-1°C. The cold suspension is then poured on a mixture of 600 ml. of 2N sodium hydroxide solution and 300 g. of ice. After partitioning, the brown aqueous layer is extracted with two 250 ml. portions of methylene chloride. The combined organic solution is washed successively with three 250 ml. portions of cold 2N sodium hydroxide solution, 600 ml. of ice water and two 400 ml. portions of brine. The solution is dried (Na2SO4) and concentrated at reduced pressure to give 172 g. of a yellow oil. This crude epoxide is dissolved in 400 ml. of n-hexane-diethyl ether (10:1 parts by volume) and applied on a column (diameter 13 cm) containing 2 kg. of silica gel (E. Merck, AG 70-325 mesh) in n-hexane-diethyl ether (10:1 parts by volume). Elution (700 ml. cuts) with this mixture gives 6,7-epoxy-3,7-dimethyl-1-(3,4-methylenedioxyphenoxy)-2-nonene.

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