Silicon-Mediated Skipped Diene Synthesis. Application to the Melon Fly Pheromone

Article abstract of DOI:10.1021/jo00255a007

The 1,4-diene unit is a key structural feature of many fatty acid derived natural products including arachidonic acid, several of the leukotrienes, and a variety of insect pheromones.In this paper substituted <2-<(trimethylsilyl)methyl>cyclopropyl>carbinols are demonstrated to cleave redily, upon treatment with acid or upon conversion to the corresponding mesylates, to give mono- and disubstituted 1,4-pentadienes.Stereoselective formation of cis and trans olefins from diastereomeric carbinols has been examined.Control of configuration at the olefin derived from the trimethylsilyl-bearing terminus of the cyclopropane system was found to be only moderate while the olefin derived from the carbinol terminus of the cyclopropane system was produced with high trans stereoselectivity.From these results it is concluded that the cleavage of the cyclopropane ring is neither significantly accelerated by, nor strongly coupled to, cleavage of the carbon-silicon bond.The high stereoselectivity observed for the formation of the trans configuration at the olefin derived from the carbinol terminus has been applied to the synthesis of a constituent of the melon fly pheromone.