F. Contreras, P. Navarro
Jul 1, 1979
Citations
0
Influential Citations
9
Citations
Journal
Journal of Heterocyclic Chemistry
Abstract
Addition reactions in acidic media have been performed on the oxirane ring of unsubstituted, 2-methyl- and 2,3-dimethyl- substituted 2,3-epoxy-4a,12a-diaza-1,2,3,4,4a,5,12,12a-octahydronaphthacene-5,12-diones. These reactions proceed in a stereospecific way; the Furst-Plattner rule of 1,2-trans-diaxial ring-opening is obeyed as can be deduced from the nmr stereochemical study on the terminal piperidazine-ring moiety of the addition products. Acylation shift effects and 1,3-syn-diaxial interactions have been utilized to assist stereochemical assignments. The geometry of the ring corresponds in most cases to a chair slightly distorted by the sp2-sp3 character of the nitrogens. Some of the less highly substituted among the cleavage products show certain peculiarities in their spectra, and are presumed to be in conformational equilibrium.