TY - JOUR
T1 - Spectroscopy and reactivity of zinc 20‐oxaporphyrin‐IX dimethyl ester
AU - Hempenius, M. A.
AU - Koek, J. H.
AU - Lugtenburg, J.
AU - Fokkens, R.
PY - 1987
Y1 - 1987
N2 - A facile method of preparing zinc 20‐oxaprotoporphyrin‐IX dimethyl ester (1) from biliverdin‐IXα dimethyl ester has been found. According to NMR spectroscopy, the oxa substituent has a pronounced influence on the properties of the macrocyclic ring system. The 1H NMR spectrum reveals an aromatic structure and 13CNMR shows that in 1 a positive charge is delocalized, in agreement with the presence of one positive charge, and further that C‐1 and C‐19 have acquired the highest positive charge. This is corroborated by the reaction with nucleophiles, especially thiolates, leading to isolated adducts which could be well characterized. The adducts are the result of nucleophilic attack on the positions 1 and 19 exclusively, which agrees well with the charge on these positions in 1. The adducts show interesting spectroscopic properties. The study of oxaporphyrins and their nucleophilic adducts may contribute to a fuller understanding of the formation and properties of bile pigments.
AB - A facile method of preparing zinc 20‐oxaprotoporphyrin‐IX dimethyl ester (1) from biliverdin‐IXα dimethyl ester has been found. According to NMR spectroscopy, the oxa substituent has a pronounced influence on the properties of the macrocyclic ring system. The 1H NMR spectrum reveals an aromatic structure and 13CNMR shows that in 1 a positive charge is delocalized, in agreement with the presence of one positive charge, and further that C‐1 and C‐19 have acquired the highest positive charge. This is corroborated by the reaction with nucleophiles, especially thiolates, leading to isolated adducts which could be well characterized. The adducts are the result of nucleophilic attack on the positions 1 and 19 exclusively, which agrees well with the charge on these positions in 1. The adducts show interesting spectroscopic properties. The study of oxaporphyrins and their nucleophilic adducts may contribute to a fuller understanding of the formation and properties of bile pigments.
UR - http://www.scopus.com/inward/record.url?scp=0008730636&partnerID=8YFLogxK
U2 - 10.1002/recl.19871060401
DO - 10.1002/recl.19871060401
M3 - Article
AN - SCOPUS:0008730636
SN - 0165-0513
VL - 106
SP - 105
EP - 112
JO - Recueil des Travaux Chimiques des Pays‐Bas
JF - Recueil des Travaux Chimiques des Pays‐Bas
IS - 4
ER -