Submitted to: Tetrahedron
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 13, 2000
Publication Date: N/A
Interpretive Summary: The Mediterranean fruit fly (medfly) is a serious pest of 253 varieties of fruits and vegetables. The establishment of this exotic pest in the continental United States would significantly curtail citrus fruit exports, a multi-billion dollar industry. In particular, California, and more recently Florida, has seen periodic infestations of this pest. More potent tand persistent chemicals are needed to monitor any impending infestations. To this end, a highly stereoselective and efficient synthesis of a compound that is a highly potent medfly attractant has been developed. Utilizing laboratory reared sterile flies, we have shown that this compound is significantly more attractive than the medfly attractants currently in use. This attractant could provide a substitute for trimedlure, which is currently used in greater than 100,000 detection traps to monitor for the accidental introduction of this pest into the continental United States.
Technical Abstract: Ethyl(1R,2R,5R)-5-iodo-2-methylcyclohexane-1-carboxylate is the most biologically active compound of ceralure, a synthetic mixture of sixteen regio- and stereoisomers of ethyl 4 (and 5)-iodo-2-methylcyclohexane-1 carboxylate. This compound was stereoselectively synthesized on a multigram scale in nine steps in 15 percent yield. Key steps of the synthesis involved an asymmetric Diels-Alder reaction, a regioselective lactonization, stereoselective reduction of the carbonyl, and inversion of configuration with iodide.