Synthesis 2002(14): 1953-1955
DOI: 10.1055/s-2002-34382
PAPER
© Georg Thieme Verlag Stuttgart · New York

A Novel Route to Iridoids: Enantioselective Syntheses of Isoiridomyrmecin and α-Skytanthine

Martin Ernst, Günter Helmchen*
Organisch-Chemisches Institut der Universität Heidelberg, Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
Fax: +49 6221 544205; e-Mail: en4@ix.urz.uni-heidelberg.de;
Further Information

Publication History

Received 14 June 2002
Publication Date:
26 September 2002 (online)

Abstract

Enantio- and diastereoselective syntheses of the iridoids (-)-isoiridomyrmecin and (+)-α-skytanthine from a common intermediate (6-bromo-3,3a,6,6a-tetrahydro-2H-cyclopenta[b]furan-2-one) were achieved. Key steps in both syntheses are conjugated nucleophilic substitutions (SN2′ anti-reactions) with C1 zinc cyanocuprates.

1

Ernst, M.; Helmchen, G. submitted.

9

This sequence of reactions was carried out with racemic compounds.

13

According to control experiments, phthalimide was formed during the preparation of the organozinc compound.