Effective Syntheses of Natural Compounds Using Ring Opening Metathesis as a Key Reaction

Abstract

The metathesis of cycloolefins C5, C7-C10, and cyclooctadiene with olefins in the presence of the heterogeneous catalyst MoCl5/SiO2 in combination with SnMe4 was studied. The control of mole ratio of monomers, catalyst concn., temp., and monomer conversion, resulted in high selectivity of target dienes and polyenes of required chain length and stereo-content. Highly pure mono- and bi-functional dienes were obtained via hydroboration-oxidn. The compds. are biol. active natural compds. such as insect sex pheromones, plant growth regulators, and fragrant components. The advantages of the combined metathesis and hydroboration-oxidn. vs. conventional fine org. chem. methods, are: few stages; simple techniques; and accessible precursors, reagents, and catalysts. The co-metathesis of cycloolefins with olefins did not produce byproducts, since all the unsatd. hydrocarbons formed in the process were recycled or converted into functional compds. [on SciFinder(R)]