Efficient synthesis of gamma-alkylidenetetronic esters by sequential Lewis acid catalyzed.
A new approach for the synthesis of gamma-alkylidenetetronic acids and esters is reported which involves Me3SiOTf-catalyzed, regio- and stereoselective cyclization of 4-alkoxy-1,3-bis(trimethylsilyloxy)-1,3-butadienes with oxalyl chloride. The alpha-hydroxy group of the butenolides is efficiently functionalized by palladium-catalyzed cross-coupling reactions via the corresponding enol triflates.
Langer
P
P
Institut für Anorganische Chemie der Georg-August-Universität Göttingen, Tammannstrasse 4, 37077 Göttingen, Germany. planger@uni-goettingen.de
Eckardt
T
T
Schneider
T
T
Göbel
C
C
Herbst-Irmer
R
R