Buchu (Barosma betulina) is a small flowering plant found in the family Rutaceae in Western Cape of South Africa, Namibia and Australia, capable of growing up to 2 meters with a simple rounded leaf that produced essential oil of strong peppermint and sweetish smell. The Buchu oil as an essential oil consist of many chemical constituents, the main components includes piperitone, pulegone, piperitone epoxide, iso-menthone, P-menthane-8-thiol3-one, 4-diosphenol. The piperitone epoxide and Pmenthane-8-thiol-3-one constituents in Buchu oil have high commercial values, which extensively used as fragrances in perform, flavor, food additives, tonic and medicinal stimulant in modern medicine in the manufacture of insecticides, antimicrobial, antiinflammatory and antioxidant in cosmetic products. The extinction threat of the plant and chemistry benefit of these chemical constituents initiate scientist with synthetic route for synthesizing the compounds from Eucalyptus dives oil and pennyroyal oil, which are also an essential oils and abundant in nature. In the synthesis, purified piperitone and pulegone from the Eucalyptus dives oil and pennyroyal oil produced two enatiotiomers of piperitone epoxide and P-menthane-8- thiol-3-one respectively. The analytical analysis such infrared and GC-Mc conducted for the starting materials, synthesis processes and synthesize products showed results of significant value in terms chemical reactions and structural re-arrangement.

Keywords : Buchu (Barosma betulina), Eucalyptus dives oil, pennyroyal oil, piperitone, pulegone, piperitone epoxide, p-menthane-8-thiol-3one, TGA, Infrared spectroscopy, GC-MS.