Insect Growth Regulators, 20. Synthesis of Cyclic Analogues of Juvenile Hormone‐III

The cyclic analogue rac‐14b of JH‐III and its 2Z isomer rac‐14a were obtained by a multi‐step synthesis starting from rac‐α‐terpineol. The Wadsworth‐Emmons reaction was applied to the formation of the carbon chain and to the introduction of the ester function (esters 8a, b and 13a, b). Morphogenetic activities of the cyclic juvenoids were compared with those observed for their acyclic analogues.