Nuclear magnetic resonance spectra of acetylacetaldehyde and malondialdehyde

Abstract
Nuclear magnetic resonance spectra of solutions of acetylacetaldehyde and malondialdehyde are reported. The values of spin–spin coupling constants indicate that the enol forms exist in the s-cis-conformation in carbon tetrachloride, chloroform, and methylene dichloride, and in the s-trans-conformation in water. Evidence is provided for keto- and hydrated keto-forms of acetylacetaldehyde in solution in chloroform and water respectively.