449143-41-3Relevant academic research and scientific papers
Enantioselective total syntheses of manzamine A and related alkaloids
Humphrey, John M.,Liao, Yusheng,Ali, Amjad,Rein, Tobias,Wong, Yue-Ling,Chen, Hui-Ju,Courtney, Anne K.,Martin, Stephen F.
, p. 8584 - 8592 (2007/10/03)
As a prelude to undertaking the total syntheses of the complex manzamine alkaloids, a series of model studies were conducted to establish the scope and limitations of intramolecular [4 + 2] cycloadditions of N-acylated vinylogous ureas with the trienic substrates 17a,b, 28a,b, and 34. These experiments clearly demonstrated that the geometry of the internal double bond and the presence of an electron-withdrawing group on the diene moiety were essential for the facile and stereoselective formation of the desired cycloadducts. The enantioselective syntheses of the manzamine alkaloids ircinol A (75), ircinal A (5), and manzamine A (1) were then completed by employing a convergent strategy that featured a novel domino Stille/Diels-Alder reaction to construct the tricyclic ABC ring core embodied in these alkaloids. Thus, the readily accessible chiral dihydropyrrole 58 was first converted in a single chemical operation into the key tricyclic intermediate 60. Two ring-closing metathesis reactions were then used to form the 13- and 8-membered rings leading to Z-72 and 74, the latter of which was quickly elaborated into ircinal A (5) via ircinol A (75). The synthetic 5 thus obtained was converted into manzamine A (1) following literature precedent. This concise synthesis of ircinal A required a total of 24 operations from commercially available starting materials with the longest linear sequence being 21 steps.
A Sulfolene-based Intramolecular Diels-Alder Approach to the Synthesis of Manzamine A
Leonard, John,Fearnley, Stephen P.,Finlay, M. Raymond,Knight, John A.,Wong, Gordon
, p. 2359 - 2362 (2007/10/02)
Synthetic studies towards manzamine A are described.A tandem sulfolene SO2 extrusion intramolecular Diels-Alder cyclisation gave the C-5 epimer of the manzamine tricyclic ABC ring system via a C-5 to C-8 diene bearing a C-5/C-6 Z-alkene.
A NOVEL APPROACH TO THE ASYMMETRIC SYNTHESIS OF MANZAMINE A. CONSTRUCTION OF THE TETRACYCLIC ABCE RING SYSTEM
Martin, Stephen F.,Liao, Yusheng,Wong, Yueling,Rein, Tobias
, p. 691 - 694 (2007/10/02)
The enantiomerically pure tetracyclic ABCE subunit of manzamine A has been constructed by an intramolecular Diels-Alder reaction of the vinylogous imide 13 to give the ABC tricyclic core 14; elaboration of 14 into 16 followed by a novel olefin metathesis reaction to form the azocine ring then delivered the tetracycle 17.
