Experiment 8 - Chemoselective Epoxidation of a Natural Terpene
Lorenzo Bazzani
Objective:
To perform a chemoselective epoxidation reaction on the natural terpene (D)-(+)-carvone (an essential oil
isolated from caraway seeds). Our reaction success will be determined by 1H NMR and IR spectroscopy. I
expect to have learned more about the selectivity of epoxides in basic conditions.
Chemical Table:
Safety and Preparedness:
1. 5% hydrogen peroxide is used to treat clean contact lenses. Should you put contact lenses freshly
treated with H2O2 in your eyes? Why not?
No, you should not do this because H2O2 causes severe eye irritation and possible burns. If
you accidentally put contact lenses freshly treated with H2O2 in your eyes, rinse your eyes with
plenty of water for 15 minutes and contact your doctor. To prevent this, contact lenses should
Chemical  | Formula  | Equivalents  | mmol  | MW(g/mol)  | Amount
(D)-(+)-carvone  | C10H14O  | 1.00  | 4.79  | 150.22  | 0.72 g
6M Aqueous NaOH  | NaOH * H2O  | ---  | ---  | ---  | 1 mL
30% Aqueous H2O2  | H2O2 * H2O  | ---  | ---  | ---  | 1.5 mL
methanol  | CH3OH  | ---  | ---  | ---  | 8 mL
product  | C10H14O2  | 1.00  | 166.22  | 4.79  | 0.796 g​​
Lorenzo Bazzani
Fatimah Abouhajar
Section 030
be rinsed with distilled water after cleaning them with H2O2 and before putting them in your
eyes.
2. Why is 30% hydrogen peroxide not used as a commercial cleaning product?
30% hydrogen peroxide is a skin irritant, causes severe eye irritation, causes irritation of the
respiratory tract, and it may cause gastrointestinal irritation, nausea, and diarrhea if swallowed.
If this product comes into contact with other cleaning products, it can create toxic fumes.
Furthermore, H2O2 is not an effective degreaser. Therefore, this product is unsafe to use and it
is also not the most effective.
Experimental Procedure:
1. Reaction Setup
1. Combine (D)-(+)-Carvone (0.75 mL, 0.72 g) and methanol (8 mL) in a 50 mL round bottom flask
containing a stir bar.
(D)-(+)-Carvone is a dark yellow liquid
Methanol is a clear liquid
H2O2 is a clear liquid
2. Cool the mixture to 0 °C in an ice bath and add 1.5 mL of 30% H2O2 dropwise, using a pipette.
3. Add 1 mL of 6M aq. NaOH solution dropwise over a period of 1-2 min, making sure you stir the
solution well. Stir the mixture at 0 °C for 15 min and then at room temperature for 20 min.
The mixture is a light yellow liquid
6M NaOH is a clear mixture
2. Isolation of Product
1. Add 10 mL of ether to the flask, and transfer to a separatory funnel.
Diethyl ether is a clear liquid
When ether is added, the mixture becomes cloudy
2. Wash the flask with another 5 mL of ether and 15 mL brine and add those solutions to the
separatory funnel.
3. Separate the layers, transferring the organic (upper) layer to an Erlenmeyer flask, and returning
the aqueous layer to the separatory funnel.
a. Extract the aqueous layer with another 10 mL of ether and add the organic layer to your
Erlenmeyer flask containing the other ether layer.
4. Repeat the extraction with another 10 mL of ether.
The distillate is a clear liquid
Aqueous phase is on the bottom
Multiple extractions performed
5. Dry the organic extract with sodium sulfate, remove the solid by gravity filtration, and remove the
ether by rotary evaporation.