Catalytic [6 pi+2 pi]-Cycloaddition of 1,2-Dienes to Bis(cyclohepta-1,3,5-trien-7-yl)alkanes in the Presence of Ti(acac)(2)Cl-2,-Et2AlCl

摘要

An efficient procedure has been developed for the synthesis of difficultly accessible 9,9'-(alkane-alpha,omega-diyl)bis[7-(diphenylmethylidene)bicyclo[4.2.1]nona-2,4-dienes] and 16,16'-(alkane-alpha,omega-diyl)bis(tricyclo-[9.4.1.0(2,10)]hexa-2,12,14-trienes) in 55-84% yields by [6 pi + 2 pi]-cycloaddition of 7,7'-(alkane-alpha,omega-diyl)bis-(cyclohepta-1,3,5-trienes) to 1,1-diphenylpropa-1,2-diene and cyclonona-1,2-diene in the presence of the catalytic system Ti(acac)(2)Cl-2-Et2AlCl. The structure of the isolated compounds has been reliably proved by modern spectral methods.