Free base meso-tetraaryl-morpholinochlorins and porpholactone from meso-tetraaryl-2,3-dihydroxy-chlorin.
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]
McCarthy
Jason R
JR
Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060, USA.
Jenkins
Hilary A
HA
Brückner
Christian
C