1,19-Disubstituted Tetra-dehydro-corrin-Nickel Complexes
David Dolphin, Harris, R.L.N., Johnson, A.W., and Kay, I.T.
Proc. Chem. Soc. London
Cyclization of 1',8'-dideoxybiladienes-ac containing terminal Me or ethoxycarbonyl groups leads to the formation of the corresponding tetradehydrocorrin-Ni complexes containing. C-1 and C-19 angular Me or ester groups. Cyclization leading to this structure involves the disappearance of 2 of the aromomatic Me peaks and the appearance of a new peak at 9.34 in the N.M.R. spectrum of the complex. Further proof of the structure is provided by ir absorption, failure to remove the metal from the complex with strong mineral acids, and the conversion of it by mild hydrolysis and decarboxylation into the corrole-Ni complex, which is identical with the complex obtained from corrole by treatment with Ni ions. Preparation of corrins of the cobalamin type by cyclization of the type described is being attempted.