1.Total Synthesis of the Strychnos Alkaloids (+/-)-Akuammicine and (+/-)-Norfluorocurarine from 3a-(o-Nitrophenyl)hexahydroindol-4-ones by Nickel(0)-Promoted Double Cyclization.
Solé D1, Bonjoch J, Bosch J. J Org Chem. 1996 Jun 26;61(13):4194-4195.
2.Efficient access to the core of the Strychnos, Aspidosperma and Iboga alkaloids. A short synthesis of norfluorocurarine.
Martin DB1, Vanderwal CD. J Am Chem Soc. 2009 Mar 18;131(10):3472-3. doi: 10.1021/ja900640v.
An efficient anionic bicyclization of tryptamine-derived Zincke aldehydes forms the basis for a three-step route to the tetracyclic ABCE core of many Strychnos, Aspidosperma, and Iboga alkaloids. This powerful reaction is showcased in a five-step synthesis of the Strychnos alkaloid norfluorocurarine from tryptamine and pyridine.
3.[Alkaloids from Vinca herbacea W.K. XI. Norfluorocurarine].
Pyuskyulev B, Ognyanov I, Panov P. Tetrahedron Lett. 1967 Nov;46:4559-62.
4.Syntheses of strychnine, norfluorocurarine, dehydrodesacetylretuline, and valparicine enabled by intramolecular cycloadditions of Zincke aldehydes.
Martin DB1, Nguyen LQ, Vanderwal CD. J Org Chem. 2012 Jan 6;77(1):17-46. doi: 10.1021/jo2020246. Epub 2011 Dec 14.
A full account of the development of the base-mediated intramolecular Diels-Alder cycloadditions of tryptamine-derived Zincke aldehydes is described. This important complexity-generating transformation provides the tetracyclic core of many indole monoterpene alkaloids in only three steps from commercially available starting materials and played a key role in short syntheses of norfluorocurarine (five steps), dehydrodesacetylretuline (six steps), valparicine (seven steps), and strychnine (six steps). Reasonable mechanistic possibilities for this reaction, a surprisingly facile dimerization of the products, and an unexpected cycloreversion to regenerate Zincke aldehydes under specific conditions are also discussed.