Assignment of relative configurations and conformational study of acyclic diastereomeric ketones

The conformational analysis and the assignment of relative configurations [( RR , SS ) and ( RS , SR )] to the dia‐stereomeric racemates of two acyclic ketones with two asymmetric carbons, ±‐2,2,7,7‐tetramethyl‐5,6‐diphenyloctan‐3‐one and ±‐5,5‐dimethyl‐1,3,4‐triphenylhexan‐1‐one, have been achieved by analysis of 1 H‐ 1 H geminal and vicinal coupling constants, 13 C– 1 H direct coupling constants and 13 C chemical shifts. This study allows the establishment of the monoconformational character of the ( RR , SS ) diastereomers. The application of the empirical equation of Haasnoot et al. supports this hypothesis.