PROSTAGLANDIN ENDOPEROXIDE NUCLEUS AND RELATED BICYCLIC PEROXIDES - SYNTHETIC AND SPECTROSCOPIC STUDIES

Several derivatives of 2, 3-dioxabicyclo[2.2.1]heptane, the strained bicyclic peroxide nucleus of prostaglandin endoperoxides, were prepared from 2, 3-dioxabicyclo[2.2.1]hept-5-enes by selective reduction with diimide or chlorination. Stereospecific cis-exo delivery of hydrogen in the reduction was demonstrated by deuterium-labeling studies. The chlorination is accompanied by molecular rearrangement involving a novel 1, 2 shift of an alkylperoxy group. A homologous series of saturated bicyclic peroxides was prepared from singlet oxygen adducts of cyclic 1, 3-dienes by reduction with diimide. The bridgehead 13C-H coupling constants observed for these bicyclic peroxides increase with decreasing ring size in parallel with increasing ring strain. With the exception of the highly strained bicyclo[2.2.1] peroxide, the first ionization energy of the bicyclic peroxides, measured by photoelectron spectroscopy, increases with increasing C-O-O-C dihedral angle. Photoelectron spectral data for a homologous series of monocyclic peroxides are also reported. © 1979, American Chemical Society. All rights reserved.