SYNTHESIS AND STRUCTURE OF NEW SYSTEMS CONTAINING PYRAMIDALIZED DOUBLE-BONDS

Syn- and anti-isomers of substituted tetracyclo[6.2.2.2(3,6).1(2.7)]te tradeca-2(7)-ene have been synthesized. In the syn-isomers steric inte ractions between cyclopropane hydrogen atoms lead to a pyramidalizatio n of the C(sp(2)) atoms of the central double bond. The parameters fro m three crystal structures are compared with geometry optimized struct ures using PCWIN, MM3, and MOPAC. Plots of X-ray distances versus theo retically optimized distances give correlation coefficients between 0. 91 and 0.97, Analysis of the discrepancies suggest modifications in so me molecular mechanics parameters are needed to model the solid state structures.