The octant rule. XX : Synthesis and circular dichroism of (1 [formula omitted],5 [formula omitted])-dimethyladamantan-2-one - predicted to have zero cotton effect

The title compound was synthesized in optically active form from adamantane. Although the methyl perturbers lie in the extended local symmetry planes of the carbonyl chromophore, and octant and quadrant rules therefore predict they should make no contributions to the Cotton effect (CE), weak negative CEs are found in cyclopentane ▪ and in CF 3CH 2OH ▪ solvents.