Macropodumines B and C (1, 2) are fused pentacyclic alkaloids previously isolated from the Chinese medicinal plant Daphniphyllum macropodum. Macropodumine B (1) possesses an amazing structural feature of a cyclopentadienyl carbanion, stabilized as a zwitterion by an internal iminium cation, which was confirmed by X-ray diffraction analysis. On the basis of the X-ray geometry, the absolute configuration of 1 was determined by employing the solid-state CD/TDDFT approach. The absolute configuration of 2 was instead determined by using TDDFT CD calculations on DFT-optimized geometries, in comparison with CD spectra recorded in solution.
|Autori:||GUO Y-W; KURTÁN T; KROHN K; PESCITELLI G; ZHANG W|
|Titolo:||Assignment of the absolute configuration of zwitterionic and neutral macropodumines by means of TDDFT CD calculations|
|Anno del prodotto:||2009|
|Digital Object Identifier (DOI):||10.1002/chir.20626|
|Appare nelle tipologie:||1.1 Articolo in rivista|