Syntheses of protoporphyrin‐IX regioselectively carbon‐13 labelled at the alpha‐vinyl carbons
A method for transformation of readily available beta‐vinyl 99% carbon‐13 enriched derivatives of protoporphyrin‐IX dimethyl ester (3‐5) into the less accessible alpha‐vinyl labelled isomers (6‐8) is described. The procedure involves thallium(III) promoted vinyl carbon rearrangement, and proceeds through 2,2‐dimethoxyethyl (e.g. 10), formylmethyl (e.g. 11), 2‐hydroxyethyl (e.g. 12) and 2‐chloroethyl (e.g. 13) porphyrins; the rearranged vinyl groups are regenerated from 2‐chloroethyl in the last step by treatment with base. No evidence of vinyl carbon scrambling in the sequence is observed, and spectroscopie data of the products are given. Copyright © 1986 John Wiley & Sons, Ltd.
Publication Source (Journal or Book title)
Journal of Labelled Compounds and Radiopharmaceuticals
Smith, K., & Fujinari, E. (1986). Syntheses of protoporphyrin‐IX regioselectively carbon‐13 labelled at the alpha‐vinyl carbons. Journal of Labelled Compounds and Radiopharmaceuticals, 23 (1), 73-82. https://doi.org/10.1002/jlcr.2580230110