Condensation-Cyclization of Carbanions with Electron-Deficient Aromatics. Formation and Structure of Delocalized Anions Containing the Bicyclononane Skeleton

Article abstract of DOI:10.1021/jo00208a006

A series of new bicyclic anions containing the bicyclo<3.3.1>nonane skeleton have been prepared using sym-trinitrobenzene, ethyl 3,5-dinitrobenzoate, and picramide as the nitroaromatic moieties.Benzoylacetone, (p-nitrobenzoyl)acetone, (m-nitrobenzoyl)acetone, 1-(ethoxycarbonyl)-1-(X-benzyl)-2-propanone (X=H, p-OCH3, p-CH3, p-Cl, p-Br, p-NO2 and o-NO2), 1-(ethoxycarbonyl)-1-(2,3-dimethylbenzyl)-2-propanone, 1-(ethoxy-carbonyl)-1-(1-naphthylmethyl)-2-propanone, and 1-(ethoxycarbonyl)-1-benzoyl-2-propanone have been utilized as the carbanion precursors.The condensation-cyclizations are initiated with triethylamine and piperidine.The cyclic adducts derived from (p-nitrobenzoyl)acetone and (m-nitrobenzoyl)acetone are identical due to loss of the nitrobenzoyl moiety.Similarly the adduct from the addendum 1-(ethoxycarbonyl)-1-benzoyl-2-propanone suffers cleavage of the benzoyl moiety.Observations on the steric effects caused by some substituents at the site of condensation and spectral characterizations of the bicyclics have been recorded.