Described is a process for preparing several 1-acyl-2,6,6-trimethylcyclohexene derivatives defined by the generic structure: ##STR1## wherein R.sub.1 is hydrogen or ethylidene having the structure:[H.sub.3 C--C.dbd. ;R.sub.2 is hydrogen or no group; one of the wavy lines is a carbon-carbon double bond and the other of the wavy lines is a carbon-carbon single bond; with the proviso that when the .DELTA..sup.2,3 bond (as shown by the wavy line between the "2" and the "3" position of the ring) is a carbon-carbon double bond, then R.sub.2 is hydrogen and R.sub.2 and the moiety: ##STR2## are so juxtaposed that the molecule having the structure: ##STR3## exists in two different isomeric forms, a "+" form and a "-" form, using as a precursor, 2,6,6-trimethyl-1-acetyl-1,3-cyclohexadiene having the structure: ##STR4##