Pummerer's ketone 1 is obtained with an overall yield of 55 % by the following sequence: Claisen rearrangement of an arylcyclohexylether 3; allylic oxidation of the methylcycloalkylphenolic derivative 4b, then spontaneous cyclisation during demethylation to give 2. 1 is obtained by dehydrogenation of 2. NMR data agree with a cis stereochemistry at C4a and C 9b.