Zinc carbenoid-mediated chain extension: preparation of alpha,beta-unsaturated-gamma-keto esters and amides.
An efficient one-pot preparation of alpha,beta-unsaturated-gamma-keto esters and amides has been developed. A zinc carbenoid-mediated chain extension of a beta-dicarbonyl substrate provides access to an intermediate zinc enolate, which is treated sequentially with a halogen and amine base. This method has been applied to a variety of ester and amide starting materials, as well as to amino acid-derived substrates and to a formal synthesis of (R,R)-(-)-pyrenophorin.
Ronsheim
Matthew D
MD
Department of Chemistry, University of New Hampshire, Durham 03824, USA.
Zercher
Charles K
CK
D000577:Amides / Q000138:chemical synthesis*; D002625:Chemistry, Organic / Q000379:methods*; D004952:Esters / Q000138:chemical synthesis; D007783:Lactones / Q000138:chemical synthesis*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D015032:Zinc / Q000737:chemistry*
D000577:Amides; D004952:Esters; D007783:Lactones; D009942:Organometallic Compounds; C013228:pyrenophorin; D015032:Zinc