title: Free base meso-tetraaryl-morpholinochlorins and porpholactone from meso-tetraaryl-2,3-dihydroxy-chlorin.
abstract: meso-Tetraaryl-2,3-dihydroxychlorins (1) were converted in one step to the novel free base macrocycles meso-tetraaryl-2,3-dialkoxy-2a-oxa-2a-homoporphyrins (morpholinochlorins, 3). Their bathochromically shifted chlorin-type UV-vis spectra indicate the presence of a nonplanar chromophore. The structure of meso-tetratolyldiethoxymorpholinochlorin (3b), as determined by X-ray crystallography, was found to be largely planar, suggesting significant conformational flexibility of these macrocycles. Oxidation of diol 1 with MnO(4)(-) generates known porpholactone 4 in high yields. [reaction--see text]
authors.affiliation: Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060, USA.
authors.forename: Jason R
authors.initials: JR
authors.lastname: McCarthy
authors.forename: Hilary A
authors.initials: HA
authors.lastname: Jenkins
authors.forename: Christian
authors.initials: C
authors.lastname: Brückner