Substituent-dependent asymmetric induction in the ring transformation of 2,3-dihydroimidazo[2,1-a]phthalazin-4-ium-6-olates effected by acetic and propionic anhydrides

Article abstract of DOI:10.1016/S0040-4020(97)00400-6

On the effect of acetic and propionic anhydrides 2,3-dihydroimidazo[2,1-a]phthalazin-4-ium-6-olates (1c-j) underwent ring transformation (1→7.8). Alternative mechanisms are applied to reason the characteristic substituent-dependent asymmetric induction observed for the transformations of the 2-monosubstituted precursors. The structures of products were determined by IR. MS. ¹H- and ¹³C-NMR (1D- and 2D) measurements supported by single crystal X-ray analysis.