In a
1-l. three-necked flask, equipped with a
dropping funnel, a
mechanical stirrer, and a
thermometer, is placed a solution of
55.2 g. (0.4 mole) of isophorone (Note
1) and
115 ml. (1.2 moles) of 30% aqueous hydrogen peroxide (
Caution! avoid contact with skin) in
400 ml. of methanol. After the contents of the flask have been cooled to 15° by means of an
ice bath,
33 ml. (0.2 mole) of 6N aqueous sodium hydroxide is added, dropwise and with stirring, over a period of 1 hour. During the addition the temperature of the reaction mixture is maintained at 15–20° with a bath of cold water (Note
2). After the addition is complete, the resulting mixture is stirred for 3 hours as the temperature of the reaction mixture is maintained at 20–25° (Note
3) and (Note
4). The reaction mixture is then poured into 500 ml. of water, and the resulting mixture is extracted with two
400-ml. portions of ether. The combined extracts are washed with water and dried over anhydrous
magnesium sulfate. After the bulk of the
ether has been removed by distillation (or flash distillation) through a
30-cm. Vigreux column (Note
5) at atmospheric pressure, the residual liquid is distilled through the
Vigreux column under reduced pressure. The yield of
isophorone oxide (Note
4) is
43–44.5 g. (
70–72%), b.p.
70–73°/5 mm.,
nD25 1.4500–1.4510.