Direct asymmetric aldol reaction of 5H-oxazol-4-ones with aldehydes catalyzed by chiral guanidines.
A new chiral bicyclic guanidine-catalyzed direct catalytic aldol reaction of 5H-oxazol-4-ones with aldehydes has been developed. The present aldol reaction proceeds smoothly with high enantioselectivity using bicyclic guanidines bearing a hydroxy group at the appropriate position, and various combinations of 5H-oxazol-4-ones and aldehydes are applicable. The method provides synthetically useful alpha,beta-dihydroxycarboxylates bearing a chiral quaternary stereogenic center at the alpha-carbon atom.
Misaki
Tomonori
T
Graduate School of Material Science, University of Hyogo, 3-2-1 Kohto, Kamigori, Hyogo 678-1297, Japan. misaki@sci.u-hyogo.ac.jp
Takimoto
Gouta
G
Sugimura
Takashi
T
D000447:Aldehydes / Q000737:chemistry*; D002384:Catalysis; D019791:Guanidine / Q000737:chemistry*; D010080:Oxazoles / Q000737:chemistry*; D013237:Stereoisomerism
D000447:Aldehydes; D010080:Oxazoles; D019791:Guanidine