1H NMR utilization of through-space effects. II-conformation of dienic ketones

The configurational and conformational assignments of the carbonyl group in the Z‐ and E‐1‐(3‐substituted‐5,5‐dimethyl‐2‐cyclohexen‐1‐ylidene)‐2‐butanones are carried out using only the through‐space effects of the carbonyl group. It is demonstrated that, regardless of the Z‐ or E‐configuration or the nature of the substituent in position 3, the conformation of the carbonyl group is always s‐cis.