METATHESIS REACTIONS OF UNSATURATED ESTERS CATALYZED BY HOMOGENEOUS TUNGSTEN COMPLEXES. SYNTHESES OF CIVETONE AND MACROLIDES

Article abstract of DOI:10.1016/S0022-328X(00)80988-2

The metathesis reactions of methyl 10-undecenoate, methyl oleate and oleyl acetate have been carried out using WCl6 and WOCl4 as primary catalysts and SnMe4, PbMe4, Cp2TiMe2, and Cp2ZrMe2 as cocatalysts.The catalyst system WOCl4/Cp2TiMe2 was found to be very active for the metathesis of the unsaturated esters and is somewhat better than the system WCl6/SnMe4.Diethyl 9-octadecene-1,18-dioate, obtained by the metathesis of ethyl oleate, was subjected to the Dieckmann cyclization.The cyclized product was decarboxylated to give civetone as a mixture of the cis and trans isomers.Preliminary studies of macrolide synthesis by the intramolecular metathesis of oleyl oleate and 10-undecenyl 10-undecenoate to afford 9-octadecen-18-olide and 10-eicosen-20-olide, respectively, have been carried out.