Preparation of #beta#-Substituted #gamma#-Keto Esters by the Grignard Reaction on N-Acylpyrazoles

摘要

Various #gamma#-keto esters were prepared by either the alcoholysis of N-(4-oxoalkanoyl)pyrazoles or the Grignard replacement of pyrazole moiety of 4-(N-pyrazolyl)-4-oxoalkanoic esters. By using 3-phenyl-l-menthopyrazole as a chiral auxiliary, #beta#-sugbstituted #gamma#-keto esters were enantisoelectively obtained.