The IR and UV spectra of enol forms of N-butyl-4-cyano-2, 3-dioxopyrrolidine and N-butyl-4-carboethoxy-2, 3-dioxopyrrolidine

Abstract

1. The five-membered chelate ring of enols of α-diketones and the six-membered chelate ring of β-cyanoketones, if it is formed, has a strength analogous to the intermolecular hydrogen bond. 2. A decrease in the conjugation in the quasiaromatic six-membered chelate ring of cyclic β-keto-esters with substituted five-membered rings is observed. © 1969 Consultants Bureau.