MESOIONIC OXAZOLONES .8. THEORETICAL-STUDY ON OXAZOLO[3,2-ALPHA]PYRIDINIUM-2-OLATE AND ITS PLANAR AND NONPLANAR ACYLATED DERIVATIVES

From four semiempirical methods tested, only MNDO and MNDO-PM3 were se lected for the study of the title compounds. Benzo-annelatian and acyl ation effects were discussed in terms of rehybridization and re-bond o rders variations. Geometric features and electronic charge distributio ns, calculated especially by the standard MNDO, were partly in agreeme nt with the newly offered experimental data. The distinction between p lanar and non-planar acylated compounds was confirmed.