Solution and Crystal Conformations of Myrionine, a New 8β-Alkyl-cis-decahydroquinoline of Myrioneuron nutans
摘要:
Myrionine (1), a new 8 beta-alkyl-cis-decahydroquinoline, was isolated from Myrioneuron nutans. Its structure was determined by spectral methods and then confirmed by X-ray analysis and total synthesis. In solution, 1 gives rise to an N-in/N-out equilibrium. The solvent has weak influence on the N-in/N-out ratio for myrionine (1), whereas together with the anions, it plays an important role for myrionine hydrochloride (9) and hydroiodide (10). The two N-in and N-out conformations obtained separately by crystallization of 9 and 10, respectively, were analyzed by X-ray diffraction.
Structure and Total Synthesis of (−)-Myrionidine and (−)-Schoberine, Antimalarial Alkaloids from <i>Myrioneuron nutans</i>
作者:Van Cuong Pham、Akino Jossang、Philippe Grellier、Thierry Sévenet、Van Hung Nguyen、Bernard Bodo
DOI:10.1021/jo801046j
日期:2008.10.3
Two new alkaloids, (5S,9S,10R)-myrionidine (1) and (5S,9S,10R,13S)-myrionamide (2), along with the known schoberine (3), were isolated from the leaves of Myrioneuron nutans (Rubiaceae), and their structures were determined from spectral analysis, including mass spectrometry and 2D NMR. The total asymmetric syntheses of (-)-myrionidine (1), (-)-schoberine (3), their enantiomers as well as their 9-epimers
by the cyclocondensation of (R)‐phenylglycinol or (1S,2R)‐1‐amino‐2‐indanol with stereoisomericmixtures (racemates, meso forms, diastereoisomers) of cyclohexanone‐based δ‐keto‐acid and δ‐keto‐diacid derivatives in enantio‐ and diastereoconvergent processes that involve dynamic kineticresolution and/or desymmetrization of enantiotopic groups. A detailed analysis of the stereochemical outcome of this