ERIC Number: EJ940781
Record Type: Journal
Publication Date: 2011-Jun
Pages: 3
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0021-9584
EISSN: N/A
Isolation and Structure Elucidation of the Terpene "[beta]"-Thujone from Cedar Leaf Oil
French, Larry G.
Journal of Chemical Education, v88 n6 p829-831 Jun 2011
Western red cedar leaf affords an essential oil characterized by high thujone content. Students in an advanced organic chemistry lab course isolate a single thujone diastereoisomer from commercially available cedar leaf oil. Treatment of crude oil, containing roughly 70% thujone, predominately as [alpha]-thujone (6.5:1), with ethanolic sodium hydroxide leads to epimerization at the chiral [alpha]-carbon. Equilibration thus inverts the diastereoisomeric ratio in favor (roughly 2:1) of the [beta]-thujone epimer. Selective formation of the bisulfite addition product from the [beta]-isomer allows for a simple purification via filtration. Release of the free ketone upon treatment with Na[subscript 2]CO[subscript 3] yields highly pure [beta]-thujone, which is characterized and identified using IR, MS, and NMR spectroscopy. (Contains 1 figure and 1 scheme.)
Descriptors: Organic Chemistry, Science Instruction, College Science, Science Laboratories, Plants (Botany), Scientific Concepts, Spectroscopy, Science Experiments
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Grant or Contract Numbers: N/A