Conformation and configuration of some α,β-unsaturated carbonyl compounds from their nuclear magnetic resonance spectra

Abstract

Nuclear magnetic resonance spectra were recorded for 95 styrenes with two functional groups (A and B) on the β-carbon atom where A, B are COCH 3 , COCH 3 ; COCH 3 , CO 2 C 2 H 5 ; CO 2 C 2 H 5 , COCH 3 ; CO 2 C 2 H 5 , CO 2 C 2 H 5 ; CO 2 C 2 H 5 , CN; and CO 2 C 2 H 5 , H. The chemical shifts of the ethylenic hydrogen and the hydrogens of the functional A and B groups were examined in detail to determine the effects of ring substituents. The configuration of the unsymmetrical styrenes and the conformation of the A and B groups as deduced from the spectra are discussed.