Enantioselective Synthesis of Ceralure B1, Ethyl cis-5-Iodo-trans-2-methylcyclohexane-1-carboxylate

Ethyl (1R, 2R, 5R)-5-iodo-2-methylcyclohexane-1-carboxylate is a potent attractant for the Mediterranean fruit fly. This compound was stereoselectively synthesized on a multigram scale in nine steps in 15% yield. Key steps of the synthesis involved an asymmetric Diels–Alder reaction, iodolactonization, stereoselective reduction of the carbonyl, and inversion of configuration with iodide.