Metalation of 4-oxazolinyloxazole derivatives. A convenient route to 2,4-bifunctionalized oxazoles.
The synthesis of an array of 5-phenyloxazole derivatives bearing a variety of hydroxyalkyl groups at the C-2 position of the heterocyclic nucleus and possessing a formyl or a carboxyl function at C-4 is reported. These bifunctionalized compounds have been efficiently prepared by addition of carbonylated electrophiles to the 2-lithio derivative of 5-phenyloxazole preliminarily equipped with an oxazoline unit at the 4-position of the oxazole nucleus. It is demonstrated that this protocol offers a double advantage since it suppresses the troublesome electrocyclic ring-opening reaction and allows access to the target compounds by simple chemical transformation of the oxazoline ring system.
Couture
Axel
A
Laboratoire de Chimie Organique Physique, UPRES A-CNRS 8009, Université des Sciences et Technologies de Lille, F-59655 Villeneuve d'Ascq Cedex, France. axel.couture@univ-lille.fr
Grandclaudon
Pierre
P
Hoarau
Christophe
C
Cornet
Joséphine
J
Hénichart
Jean-Pierre
JP
Houssin
Raymond
R
D004791:Enzyme Inhibitors / Q000138:chemical synthesis; D008094:Lithium / Q000737:chemistry*; D010080:Oxazoles / Q000138:chemical synthesis*
D004791:Enzyme Inhibitors; D010080:Oxazoles; D008094:Lithium