Facile asymmetric synthesis of the core nuclei of xanthanolides, guaianolides, and eudesmanolides.
[reaction: see text] Bicyclic and tricyclic gamma-butyrolactones with 5,7-, 5,6,5-, 5,6,6-, or 5,7,5-fused ring systems, being found in xanthanolides, eudesmanolides, and guaianolides, were readily synthesized from methyl furan-2-carboxylic acid. Key steps were a copper(I)-catalyzed asymmetric cyclopropanation, Sakurai allylations, intramolecular ene reactions, and ring-closing metathesis reactions.
Nosse
Bernd
B
Institut für Organische Chemie der Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany.
Chhor
Rakeshwar B
RB
Jeong
Won Boo
WB
Böhm
Claudius
C
Reiser
Oliver
O