The four diastereoisomeric 6-tert-butyl-4-oxoperhydroazulenes (3-6) have been prepared and characterized. Molecular mechanica calculations suggest that each of these ketones will exist as one or both of a pair of closely related conformers as follows: 3, C-3 or TC-7; 4, TC-1 or TC-2; 5, B-3 or TB-4; 6, TC-4 or TC-5. A combination of'H NMR data and X-ray crystallographic data support the correctness of these predictions.
