Merck

Intramolecular Hydrogen Bonding and Linear Pentapyrrole Conformation.

Monatshefte fur chemie (2014-08-12)
D Timothy Anstine, David A Lightner
ABSTRACT

Three new linear pentapyrrole rubinoid analogs: 2,3,7,8,17,18,22,23-octamethyl-12,13-bis-(2-carboxyethyl)-1,10,15,24,25,27,28,29-octahydro-27H-pentapyrrin-1,24-dione and 2,3,8,12,13,17,22,23-octamethyl-7,18-bis-(2-carboxyethyl)-1,10,15,24,25,26,27,28,29-octahydro-27H-pentapyrrin-1,24-dione, and its 7,18-dihexanoic acid analog were synthesized, respectively, from 2,3,7,8-tetramethyl-(10H)-dipyrrin-2-one, from 2,3,8-trimethyl-7-[2-(methoxycarbonyl)ethyl]-(10H)-dipyrrinone, and 2,3,8-trimethyl-7-[5-(methoxycarbonyl)pentyl]-(10H)-dipyrrinone. 13C NMR and 1H NMR measurements in (CD3)2SO confirmed the pentapyrrole structures, while 1H NMR data indicate intramolecular hydrogen bonding between the CO2H and dipyrrinone groups. Molecular mechanics modeling studies suggest stable U-shape conformations capable of encapsulating small planar aromatic molecules.

MATERIALS
Product Number
Brand
Product Description

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