Ozonolysis of Alkenes

Source: Vy M. Dong and Zhiwei Chen, Department of Chemistry, University of California, Irvine, CA

This experiment will demonstrate an example of an ozonolysis reaction to synthesize vanillin from isoeugenol (Figure 1). Ozonolysis of alkenes, an oxidation reaction between ozone and an alkene, is a common method to prepare aldehydes, ketones, and carboxylic acids. This experiment also demonstrates the use of an ozone generator and a low temperature (−78 °C) reaction.

Figure 1. Diagram showing the ozonolysis of isoeugenol to vanillin.

Vanillin was obtained as a white solid (150 mg, 76% yield); m.p. 76-79 °C; ¹H NMR (400 MHz, CDCl₃) δ 9.82 (br s, 1H), 7.43-7.41 (m, 2H), 7.04 (d, J = 8.8 Hz, 1H), 6.30 (s, 1H), 3.96 (s, 3H).

In this experiment, we have demonstrated the synthesis of vanillin from isoeugenol using the ozonolysis reaction. Also, using an ozone generator while performing a low temperature reaction was shown.

Ozonolysis is a useful reaction to prepare aldehydes, ketones, and carboxylic acids from alkenes. It has been applied in natural product synthesis and industrial-scale preparation of pharmaceuticals. Artemisinin is a potent antimalarial agent and was one of the nat