Petroleum Chemistry, Vol.55, No.7, 549-551, 2015
Stereochemical features of 1,7-octadiene metathesis on the MoCl5/SiO2-Me4Sn catalytic system
It has been established that the metathesis reaction of 1,7-octadiene (OD) proceeds smoothly by two pathways in the direction of the formation of the product of the chain growth, 1,7,13-tetradecatriene, and intramolecular cyclization into cyclohexene. It has been shown that, at the low (9%) conversion of OD, the content of cyclohexene is 72%, while that of 1,7,13-tetradecatriene is 28%. As the reaction proceeds, the content of cyclohexene increases and becomes 97% at the conversion of 99%, i.e., almost all 1,7,13-tetradecatriene formed cyclizes into cyclohexene. At relatively low conversions of OD (9-55%), the stereo-composition of 1,7,13-tetradecatriene does not differ from the stereo-composition of the products of the homometathesis and cometathesis of the linear structures (Z/E=(25-18)/(75-82)). The content of 1,Z-7,13-tetradecatriene decreases sharply from 8.0 to 0.9% with the increase in the conversion. This is explained by a higher proneness of the Z-stereoisomer to the cyclization.