Title
Synthesis of purpuroine A, nakirodin A and MDN-0104: The hidden puzzles and risk of error in their configurational assignments
Author
Wen-Ju Wu, Yikang Wu, Bo Liu
Year
2017
Journal
Tetrahedron
Abstract
The unusual (R) configuration previously assigned (with seemingly undoubted evidence) to purpuroin A and nakirodin A was disproved by synthesis. The optical rotation and NMR data for structure assigned for salt-free nakirodin A were made available for the first time. The difficulty and potential risk of error in configurational assignments of diastereomers for remote stereocenters were exemplified through MDN-0104. However, comparisons of the delicate 13C NMR deviations may still provide solutions to such problems.
Instrument
J-810
Keywords
Circular dichroism, Absolute configuration, Natural products