Treatment of 2'-deoxyadenosine with acrolein at pH 4.6 in 37 degrees C affords unstable adducts containing either one or two fused ring systems where the hydroxypropano units are derived from acrolein. Since the use of 2'-deoxyadenosine resulted in the creation of at least four diastereoisomers for the adduct made up of two fused rings, therefore, for identification and assignment of the products, 9-ethyladenine was used instead as the starting material in the reaction. The products, 3E and 4E, were structurally characterised by UV, mass spectrometry and NMR spectroscopy.