ORBITAL DISTORTION ARISING FROM REMOTE SUBSTITUENTS - NITRATION, REDUCTION, AND EPOXIDATION OF FLUORENES BEARING A CARBONYL OR AN OLEFIN GROUP IN SPIRO GEOMETRY

Nitration of spiro[cyclopentane-1,9'-fluoren]-2-one with acetyl nitrate predominantly gave the 4-nitro derivative. In the reduction of substituted spiro[cyclopentane-1,9-fluoren]-2-ones, the anti alcohols were favored in all cases. In the epoxidation of substituted spiro[cyclopent-2-ene-1,9'-fluorenes], the syn epoxides were favored. These distributions of the products can be interpreted in terms of orbital perturbations arising from interactions of the pi orbitals of the aromatic and the carbonyl moieties or of the pi orbitals of the aromatic and the olefin moieties, i.e., orbital mixing perturbation of the aromatic pi orbitals through the pi orbital of the bisected carbonyl (or olefin) group and the reciprocal perturbation of the pi orbital of the carbonyl (or olefin) group arising from the orthogonal pi aromatic orbitals.