Collect. Czech. Chem. Commun. 1987, 52, 714-726

Structural investigations of substituted methylenemalonaldehydes by X-ray crystallography and NMR spectroscopy

Tapani A. Pakkanena, Vesa Nevalainena, Vladimír Králb, Reino Laatikainenc and Zdeněk Arnoldb

a Department of Chemistry, University of Joensuu, SF-80101 Joensuu 10, Finland
b Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6, Czechoslovakia
c Department of Chemistry, University of Kuopio, SF-70211 Kuopio 21, Finland


Crystal and molecular structure of three substituted methylenemalonaldehydes I-III was studied. The spatial arrangement of the monosubstituted derivative I differs significantly from that of the disubstituted methylenemalonaldehydes II and III, not only in the solid state conformation of the malonaldehyde fragment but also in the length of the ethylenic C=C double bond and in its distorsion. The structures found in crystal are compared with conformations in solutions determined by NMR spectroscopy.