Efficient synthesis of pyranostilbenes and their application to artocarbene and pawhuskin B

ORGN 699

Ene Jin Jung, ejsword@hanmail.net, Byung Ho Park, and Yong Rok Lee, yrlee@yu.ac.kr. School of Chemical Engineering and Technology, Yeungnam University, Gyeongsan, 712-749, South Korea
Pyranostilbenes with the benzopyran moiety on the stilbene are found in nature. Recently, we developed a new and useful methodology for preparing a variety of benzopyrans using ethylenediamine diacetate (EDDA)-catalyzed reactions of resorcinols with a,b-unsaturated aldehydes. These reactions involve cycloadditions through an electrocyclization or hetero Diels-Alder reaction and provide a rapid route for the synthesis of benzopyran derivatives with a variety of substituents on the pyranyl ring. As part of an ongoing study of the synthetic efficacy of this methodology, we describe herein an efficient and general synthesis of a variety of pyranostilbene derivatives through a domino aldol-type reaction and an electrocyclization reaction. As an application of this methodology, we also report on the first total synthesis of the naturally occurring artocarbene and pawhuskin B.