Compounds of the formula ##STR1## wherein R.sup.1 is an acyl group or certain optionally halo-substituted hydrocarbyl groups, and X is --CH.sub.2 CH(OCH.sub.3).sub.2, --CH.sub.2 CHO, --CH.dbd.CHOR.sup.2 in which R.sup.2 is acyl, --CHO,--C(O)Cl, --C(O)Br or --C(O)OR in which R is H, a salt-forming cation, an alkyl group or the residue of a pyrethroid alcohol are new pesticides or intermediates therefore. The compounds are prepared using a multi-step synthesis starting from the natural terpene, 3-carene.