Syntheses of bile pigments. Part 15. First unequivocal assignment of the absolute configuration of an urobilinoid bile pigment by X??ray diffraction analysis of its …

C Pasquier, A Gossauer, W Keller…

Index: Pasquier; Gossauer; Keller; Kratky Helvetica Chimica Acta, 1987 , vol. 70, # 8 p. 2098 - 2109

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Citation Number: 7

Abstract

Abstract (−)-(4S, 16S)-8, 12-bis [de (2-carboxyethyl)] mesourobilin-IIIα hydrochloride (8) has been synthesized from the enantiomerically pure 1, 4, 5, 10-tetrahydro-1-oxodipyrrin-9- carboxylic-acid precursor 6a whose absolute configuration was determined by X-ray diffraction analysis of the N-[(S)-1-(1-naphthyl) ethyl] carboxamide 7b. The present results prove unequivocally that an (S, S)-configurated urobilin chromophore displays a negative ...