Pfeiffer William P, Dey Sanjeev K, Falk Heinz, Lightner David A
CIMA Labs, Inc., Eden Prairie, MN 55344 USA.
Milliken & Company, P. O. Box 1926, Spartanburg, SC 29304 USA.
Monatsh Chem. 2014 Jun;145(6):963-981. doi: 10.1007/s00706-014-1191-z.
The syntheses are described for centrally expanded bilirubin analogs: -homorubins with propionic and butyric acid groups in the positions corresponding to the propionic acids of bilirubin. Their syntheses were accomplished by coupling two equivalents of a reactive monopyrrole (5-(bromomethylene)pyrrolin-2-one) to a dipyrrylethane. The corresponding -homoverdins and dehydro- -homoverdins were prepared by dehydrogenating the rubins or their dimethyl esters using DDQ. As supported by NMR measurements and molecular mechanics calculations, the homorubins are found to engage in conformation-determining intramolecular hydrogen bonding between the dipyrrinone and carboxylic acid moieties. Likewise, the homoverdins are believed to favor intramolecularly hydrogen-bonded conformations.
即在与胆红素丙酸相对应的位置带有丙酸和丁酸基团的高胆红素。它们的合成是通过将两当量的活性单吡咯（5-(溴亚甲基)吡咯啉-2-酮）与二吡咯乙烷偶联来完成的。相应的高胆红素氧化产物和脱氢高胆红素氧化产物是通过使用2,3-二氯-5,6-二氰基-1,4-苯醌（DDQ）对高胆红素或其二甲酯进行脱氢制备的。核磁共振（NMR）测量和分子力学计算表明，高胆红素在二吡咯酮和羧酸部分之间形成了决定构象的分子内氢键。同样，高胆红素氧化产物被认为有利于分子内氢键结合的构象。
