Total synthesis of cis and trans-hydroxyglimepiride: active metabolite of glimepiride
摘要:
Syntheses of trans-hydroxyglimepiride 2b, a human metabolite of the blood glucose lowering agent glimepiride I and its corresponding cis-stereoisomer 2a, are described. (C) 2003 Elsevier Science Ltd. All rights reserved.
Relative stereochemistry of the A ring of plant bile pigments
作者:Robert W. Schoenleber、Youseung Kim、Henry Rapoport
DOI:10.1021/ja00321a026
日期:1984.5
synthesis and characterization, including the stereochemistry, of a series of 3,4-dihydropyrromethenones and 2,3-dihydrodioxobilins are described. High-resolution /sup 1/H NMR spectral analysis allows the determination of the A ring coupling constants for a series of cis and trans model compounds. From these data and correlations, the relativestereochemistry in the A ring of phycocyanin and similar bile
描述了一系列 3,4-dihydropyrromethenones 和 2,3-dihydrodioxobilins 的合成和表征,包括立体化学。高分辨率 /sup 1/H NMR 光谱分析允许确定一系列顺式和反式模型化合物的 A 环耦合常数。根据这些数据和相关性,可以得出藻蓝蛋白 A 环中的相对立体化学和类似胆色素结构的结论。
Diastereoselective synthesis of phycocyanobilin-cysteine adducts
作者:John E. Bishop、Jon O. Nagy、John F. O'Connell、Henry Rapoport
DOI:10.1021/ja00021a032
日期:1991.10
Methodology is presented for the synthesis of two diastereomers of a cysteine-linked phycocyanobilin derivative. The crucial reaction is a diastereoselective 1,6-Michael addition of cysteine methyl ester to an appropriate dihydropyrromethenone educt. The diastereomers so generated were then elaborated to two phycocyanobilin trimethyl esters. Definitive assignments of relative stereochemistry, double bond geometry, and solution conformation are accomplished by application of ROESY NMR experiments, while absolute stereochemical assignments are based on degradation to compounds of known chirality.
Plieninger; Decker, Justus Liebigs Annalen der Chemie, 1956, vol. 598, p. 198,205