Synthetic Lemon Grass Oil Terpenes are responsible for characteristic flavors, odors, and colors of many natural products. Many laboratory manuals introduce steam distillation by separating terpenes from spices, seeds, or natural oils. One such separation is steam distillation of citral from lemon grass oil.',z T o overcame a difficulty in finding lemon grass ail t o purchase, a synthetic mixture has been prepared. The synthetic lemon grass oil is 60%(volume) of citral(3,7-dimethyl-2,6-octadienal;available from Matheson, Coleman, and Bell, Manufacturing Chemists), 20% (volume) of 1.2-propanedial (available from Eastman Kadak Co.), and 2Wb (volume) of 1,3-butanediol (available from Eastman Kodak Co.). The mixture is transparent a t room temperature. During cold weather, turbidity and phase separation may be removed by placing the stock bottle in a pan of hot water. At the end of the laboratory period, students submit the purified citral as a "prep." This citral, most expensiveconstituent of the mixture, can be reused in another batch of synthetic lemon grass oil to be prepared during a subsequent semester. Fieser, L. F., and Williamson, K. L., "Organic Experiments," (3rd Ed.) D. C. Heath and Co., Lexington, Massachusetts, 1975, pp. 61-6. Roberts, R. M., Gilbert, J. C., Rodewald, L. B., and Wingrove, A. S., "An Introduction to Modern Experimental Organic Chemistry," (2nd Ed.) Holt, Rinehart, and Winston, he., New York, 1974, pp. 423-6.
Texas Wealeran College Fort Worth, 76105
306 1 Journal of Chemical Education
C. W. Schimelpfenig
