A pyrrole adduct of 5,20-diphenyl-10,15-di(p-tolyl)-2-oxa-21-carbaporphyrin [(H,pyr)OCPMH2 reacted with sodium ethanolate to yield 5,20-diphenyl-10,15-di(p-tolyl)-3-ethoxy-3-(2'-pyrrol)-2-oxa-21-carbapor phyrin ((EtO,pyr)OCPH]H-2. Subsequently, "true" O-confused oxaporphyrin with a pendant pyrrole ring [(pyr)OCPMH was formed by the addition of acid to [(EtO,pyr)OCPH]H-2, which triggered an ethanol elimination. In the course of this process, the tetrahedraltrigonal rearrangements originated at the C(3) atom. Insertion of zinc(II), cadmium(II), and nickel(II) into [(pyr)OCPH]H yielded [(pyr)OCPH]Zn"CI, [(pyr)OCPMCdllCI, and [(pyr)OCP]Ni". The formation of [(pyr)OCP]Ni" was accompanied by the C(21)H dehydrogenation step. The nickel(II) ion of [(pyr)OCP]Ni", coordinated to a dianionic macrocyclic ligand, is bound by three pyrrolic nitrogens and a trigonally hybridized C(21) atom of the inverted furan. The pyrrole-appended O-confused carbaporphyrin acts as a monoanionic ligand toward zinc(II) and cadmium(II) cations. Three nitrogen atoms and the C(21)H fragment of the inverted furan occupy equatorial positions. In H-1 H-1-NMR spectra, the unique inner C(21)H resonances of the inverted furan ring are located at 0.15 ppm for [(pyr)OCPMZn"Cl, and at 0.21 ppm for [(pyr)OCPMCdllCI. The proximity of the furan fragment to the metal ion induces direct scalar couplings between the spin-active nucleus of the metal ((111/113) Cd) and the adjacent H-1 nucleus. The interaction of the metal ion and C(21)H was also reflected by significant changes in carbon chemical shifts ([(pyr)OCPH]Zn"Cl, 78.3 ppm; [(pyr)OCPH]Cd"CI, 81.4 ppm; the free base, 101.3 ppm). The density functional theory (DFT) has been applied to model the molecular structures of zinc(II) and cadmium(II) complexes of O-confused oxaporphyrin with an appended pyrrole ring. The Cd . .. C(21) distance in the optimized structure exceeds the typical Cd-C bond lengths, but is much shorter than the corresponding van der Waals contact.