The 2,3-secochlorin-2,3-dione system

Abstract

Cleavage of nickel(II) octaethyl-2,3-dihydroxychlorin 3 with lead tetraacetate gives the novel octaethyl-2,3-secochlorin-2,3-dione system as its nickel(II) complex 4, which on treatment with basecyclisesto a novel homoporphyrinone structure 5; electronic spectra are presented: 4 and 5 are seen as representing chromophores that may arise in chlorophyll catabolism.