
TY  - JOUR
A1  - Clezy, PS 
A1  - Fookes, CJR 
A1  - Sternhell, S 
T1  - The chemistry of pyrrolic compounds. XL. A new synthesis of protoporphyrins III and XIII and a <sup>1</sup>H N.M.R. study of the preferred pathway of electron delocalization in the porphyrin macrocycle
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1978
VL  - 31
IS  - 3
SP  - 639
EP  - 648
KW  - 
UR  - https://doi.org/10.1071/CH9780639 
N2  - The synthesis of protoporphyrins III and XIII as the dimethyl esters has been completed by an oxidative cyclization of biladiene-ac intermediates. Protoporphyrin III has been converted into deuteroporphyrin III and measurements of the proton coupling constant in the allylic unit, CH3-C=C-H, of this latter porphyrin point to the double bond of this system having a significantly diminished bond order. This finding is in accord with the view that the &#960;-electron delocalization pathway in the porphyrin macrocycle involves the periphery of the molecule. 
ER  -

