Diastereoselective synthesis of phycocyanobilin-cysteine adducts
摘要:
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.
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.