Efficient synthesis of polycycles with a citran and a cyclol nucleus

ORGN 150

Eun Mi Jung, yrlee@yu.ac.kr, Yong Rok Lee, yrlee@yu.ac.kr, and Jung Hee Kim. School of Chemical Engineering and Technology, Yeungnam University, 214-1, Dae-dong, Kyongsan, 712-749, South Korea
Polycycles with a citran and a cyclol nucleus are widely distributed in nature, and have a range of biological and pharmacological properties. Among these, cannabinoids containing a citran and a cyclol moiety have been isolated from Cannabis sativa, which is also known as marijuana and hashish. This plant contains a group of more than 60 structurally related terpenophenolic compounds and has been used as a psychotomimetic drug since ancient times. Recently, we have developed a new and facile methodology for preparing benzopyrans by ethylenediamine diacetate-catalyzed reactions of resorcinols to enals. These reactions involve a formal [3+3]-cycloaddition via an electrocyclization. As part of an ongoing examination of the synthetic efficacy of this methodology, we investigated ethylenediamine diacetate-catalyzed condensation of substituted trihydroxybenzenes with citral or trans,trans-farnesal to yield polycycles. We report herein an efficient synthesis of polycycles and also a synthetic route to biologically interesting natural clusiacitran A, deoxybruceol, and rubranine.

Acknowledgment: This work was supported by grant No. RTI04-01-04 from the Regional Technology Innovation Program of the Ministry of Commerce Industry and Energy (MOCIE).