STEREOSELECTIVE SYNTHESIS OF THE PROPOSED AMERICAN CONEFLOWER JUVENILE-HORMONE MIMIC - SOME OBSERVATIONS ON THE CYCLOPROPYLCARBINYL REARRANGEMENT IN SUBSTITUTED SYSTEMS

A stereoselective synthesis of the proposed structure (1) of echinolone, the potent juvenile hormone mimic from the American coneflower, is reported. Oxygen and trisubstituted olefin functionality were introduced through a cyclopropylcarbinyl rearrangement of carbinol 25. The complexity of related rearrangements in model systems has been found to be a function of the presence or absence of remote unsaturation. Synthetic racemic 1 has been found to be devoid of JH activity in a standard assay, and these results are discussed with regard to the structure of the natural product. © 1979, American Chemical Society. All rights reserved.