Synthesis of naturally occurring o-heterocyclic compounds of biological activity
S. Antus, K. Gul�csi, L. Juh�sz, L. Kiss, and T. Kurt�n
Department of Organic Chemistry, University of Debrecen,
H-4010 Debrecen,
P.O. Box 20, Hungary
Abstract: The total synthesis of ()-cabenegrin A-I was
achieved via ()-6aR,11aR maackiain, which was obtained
by optical resolution of racemic maackiain using S-()-alpha-methylbenzyl
isocyanate. The synthesis of rac-maackiain was performed both
with the Heck oxyarylation of 7-benzyloxy-2H-chromene and the
BF3OEt2 mediated ring closure of isoflavan-4-ol
derivatives, the latter of which provided much higher yields. The first
enantioselective synthesis of trans-6aS,11aR-pterocarpan
and its conversion to cis-6aS,11aS -ptarocarpan
was also presented starting from racemic 2'-benzyloxyflavanone. Their
stereochemistry was deduced by circular dichroism (CD) as well as by
X-ray analysis of the ketal intermediate.
*Lecture presented at the Polish-Austrian-German-Hungarian-Italian Joint Meeting on Medicinal Chemistry, Krak�w, Poland, 15-18 October 2003. Other presentations are published in this issue, pp. 907 -1032.
Page last modified 8 July 2004.
Copyright © 2004 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web
manager.