Abstract: A method for making a bicyclic lactone comprising heating under aqueous acidic conditions a beta, gamma unsaturated cyclic nitrile and an aldehyde, for a length of time sufficient to convert at least a portion of the reactants to a bicyclic lactone of the formula ##STR1## wherein R.sub.3 is --H; R.sub.4, R.sub.5, and R.sub.6 are independently selected from the group consisting of --H, --CH.sub.3 ; R.sub.2 is selected from the group consisting of --H, --CH.sub.3, and --CH.sub.3, and --C.sub.2 H.sub.5 ; R.sub.8 is --H or --CH.sub.3 ; m is an integer from 1 to 5; o is 0, 1, 2, or 3; and p is 0, 1, or 2; provided that the sum of m+o+p is an integer from 3 to 5; either R.sub.3 or R.sub.8 together with R.sub.7 represents a carbon-carbon bond. The method uses commercially available and relatively inexpensive raw materials as reactants.