SYNTHESIS OF NATURAL COMPOUNDS VIA THE CYCLOOLEFIN COMETATHESIS WITH ALPHA-OLEFINS

Cometathesis of cycloolefins with alpha-olefins has been studied in th e presence of a MoCl5/SiO2-SnMe4 catalyst. Three types of polyenes wer e observed in the products of this reaction: polyenes without any term inal double bond and those having one or two such bonds. It was shown that stereoselectivity of the cometathesis depends on cycloolefin ring size and reaction conditions. In some cases, the content of cis-isome rs of 1,Delta-dienes in final mixture reached 63-70%. The obtained pol yenes were functionalized via a selective hydroboration of terminal do uble bonds. A technologically prospective strategy has been developed for the preparation of great variety of natural biologically active co mpounds (insect sex pheromones, growth regulators, fragrant compositio n components) on the basis of the cometathesis and hydroboration. (C) 1998 Elsevier Science B.V. All rights reserved.