The present invention provides organoleptic compositions which upon thermolyis, hydrolysis or both, release an odorant molecule. They find utility, for example, in tobacco, in tobacco paper, and as additives to food, beverages or gum. The compositions contain one or more dicarboalkoxy dioxolane derivatives having the following formula: ##STR1## wherein R.sup.1 and R.sup.2 are, independently, --CO.sub.2 R.sup.3 wherein R.sup.3 is --H.sub.3 or lower alkyl, provided that in at least one of R.sup.1 and R.sup.2, R.sup.3 is lower alkyl; wherein Z is a direct bond, or --CH.dbd.C(R.sup.4)--; where R.sup.4 is --H or alkyl group; and Y is ##STR2## where R.sup.5 and R.sup.6 are independently --H, lower alkyl or --OR.sup.7 where R.sup.7 is --H or lower alkyl.