Molecules 2009, 14, 3411-3424; doi:10.3390/molecules14093411 OPEN ACCESS
molecules ISSN 1420-3049 www.mdpi.com/journal/molecules Article
Fast and Green Microwave-Assisted Conversion of Essential Oil Allylbenzenes into the Corresponding Aldehydes via Alkene Isomerization and Subsequent Potassium Permanganate Promoted Oxidative Alkene Group Cleavage Thi Xuan Thi Luu 1, Trinh To Lam 2, Thach Ngoc Le 2 and Fritz Duus 1,* 1
2
Department of Science, Systems, and Models, Roskilde University, P.O. Box 260, DK-4000, Roskilde, Denmark; E-mail:
[email protected] (T.X.T.L.) Department of Organic Chemistry, University of Science, National University of Ho Chi Minh City, 227 Nguyen Van Cu, Ho Chi Minh City, Vietnam; E-Mail:
[email protected] (T.T.L.);
[email protected] (T.N.L.)
* Author to whom correspondence should be addressed; E-Mail:
[email protected]. Received: 12 August 2009; in revised form: 2 September 2009 / Accepted: 2 September 2009 / Published: 3 September 2009
Abstract: Essential oil allylbenzenes from have been converted quickly and efficiently into the corresponding benzaldehydes in good yields by a two-step “green” reaction pathway based on a solventless alkene group isomerization by KF/Al2O3 to form the corresponding 1-arylpropene and a subsequent solventless oxidation of the latter to the corresponding benzaldehyde by KMnO4/CuSO45H2O. The assistance by microwave irradiation results in very short reaction times (
