Diels-Alder reactions of highly pyramidalized tricyclo[3.3.0.03,7]oct-1(5)-ene derivatives:: further chemistry of pentacyclo[6.4.0.02,10.03,7.04,9]dodeca-5,8,11-triene

A study of the trapping of highly pyramidalized tricyclo[3.3.0.0(3,7)]oct-1(5)-ene derivatives (generated from a 1,2-diiodo precursor on reaction with t-BuLi, 0.45% sodium amalgam and molten sodium) with different dienes (11,12-dimethylene-9,10-dihydro-9,10-ethanoanthracene, 1,3-diphenylisobenzofuran, 2,5-dimethylfuran and furan) is presented. Byproducts from the trapping of pentacyclo[6.4.0.0(2,10),0(3,7),0(4,9)]dodeca-5,8,11-triene with 1,3-diphenylisobenzofuran have been synthesized and fully characterized, including an X-ray diffraction analysis. Also, the above triene has been cross coupled with 3,7-dimethyltricyclo[3.3.0.0(3,7)]oct-1(5)ene to give a tetrasecododecahedratetracne derivative. (c) 2005 Elsevier Ltd. All rights reserved.