Abstract
A novel approach for the synthesis of morpholin-2-one derivatives from dialkyl dicyanofumarates and β-amino alcohols is presented. The reaction takes place under mild conditions via an addition-elimination-lactonization pathway. The formation of the six- membered ring occurs selectively leading to a single diastereomer. In contrast to arylhydrazines, the reaction of hydrazine hydrate with dicyanofumarates yields pyrazol-3(2H)-ones and not 5-aminopyrazoles.