16984-84-2Relevant articles and documents
Atropisomerism in linear tetrapyrroles
Boiadjiev, Stefan E,Lightner, David A
, p. 7411 - 7421 (2002)
Novel bilirubin and biliverdin congeners with propionic acids replaced by o-carboxyphenyl exhibit diastereomerism due to axial chirality about the carbon-carbon single bond linking the o-carboxyphenyl group to a pyrrole ring. Evidence for atropisomerism was found even in the monopyrrole precursor, ethyl 3,5-dimethyl-4-(o-carboxyphenyl)pyrrole-2-carboxylate. Like bilirubin, o-carboxyphenyl rubin 1a adopts an intramolecularly hydrogen-bonded ridge-tile conformation in nonpolar solvents. In solutions containing optically active amines or human serum albumin 1a exhibits intense bisignate exciton coupling-type induced circular dichroism for its long wavelength absorption near 400nm.
