Org. Synth. 1957, 37, 58
DOI: 10.15227/orgsyn.037.0058
ISOPHORONE OXIDE
[Cyclohexanone, 2,3-epoxy-3,5,5-trimethyl-]
Submitted by Richard L. Wasson and Herbert O. House
1.
Checked by James Cason and Ralph J. Fessenden.
1. Procedure
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.
2. Notes
1.
A
technical grade of isophorone, b.p. 80–84°/9 mm., nD25 1.4755, purchased from Eastman Kodak Company, was employed for this preparation.
2.
If the temperature of the reaction mixture is less than 15°, the reaction does not begin. When the resulting mixture is subsequently warmed to room temperature the exothermic reaction which results is difficult to control
(Note 3).
3.
If the temperature of the reaction mixture is allowed to rise above 30°, the yield of
isophorone oxide is diminished.
4.
If desired, the course of the reaction may be followed by means of the optical density of the reaction mixture at 235 mμ. The ultraviolet spectrum of
isophorone has a maximum at 235 mμ (ε 13,300); the ultraviolet spectrum of
isophorone oxide has a maximum at 292 mμ (ε 43). A total reaction time of 4 hours under the conditions specified was found to be ample for the complete conversion of
isophorone to its oxide. If the conversion is not complete, the product cannot be separated from the unchanged
isophorone without recourse to precise fractional distillation. The absence of
isophorone from the final product may be verified by examination of the spectrum at 235 mμ.
5.
When the checkers distilled the product through a simple type of
Podbielniak column of 65-cm. length, with heated jacket and partial reflux head, the boiling range was 1°, 74–75°/6 mm., but the yields and index of refraction were the same as those reported by the submitters.
3. Discussion
Isophorone oxide has been prepared by the epoxidation of
isophorone with alkaline
hydrogen peroxide.
2,3
This preparation is referenced from:
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
methanol (67-56-1)
ether (60-29-7)
sodium hydroxide (1310-73-2)
hydrogen peroxide (7722-84-1)
magnesium sulfate (7487-88-9)
Isophorone oxide,
Cyclohexanone, 2,3-epoxy-3,5,5-trimethyl- (10276-21-8)
isophorone
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