A divergent strategy for the total syntheses of the indole terpenoid anominine (1) and its natural congener tubingensin A (2) has been developed. The common intermediate 11 bearing all of the required stereogenic centers for both natural products was first assembled by employing a Ueno-Stork radical cyclization and a Sc(OTf)(3)-mediated Mukaiyama aldol reaction to form the key C-C bonds in a stereocontrolled manner. The route to anominine features a radical deoxygenation followed by an efficient side-chain installation, while the path to tubingensin A exploits a CuOTf-promoted 6 pi-electrocyclization/aromatization sequence to forge the central region of the pentacyclic scaffold.
A divergent strategy for the total syntheses of the indole terpenoid anominine (1) and its natural congener tubingensin A (2) has been developed. The common intermediate 11 bearing all of the required stereogenic centers for both natural products was first assembled by employing a Ueno-Stork radical cyclization and a Sc(OTf)(3)-mediated Mukaiyama aldol reaction to form the key C-C bonds in a stereocontrolled manner. The route to anominine features a radical deoxygenation followed by an efficient side-chain installation, while the path to tubingensin A exploits a CuOTf-promoted 6 pi-electrocyclization/aromatization sequence to forge the central region of the pentacyclic scaffold.
Agelasine F has previously been isolated from marine sponges (Agelas sp.) and has been associated with various bioactivities including inhibitory activity on Mycobacterium tuberculosis. No total synthesis of this natural product has been reported. ent-Agelasine F has now been synthesized for the first time, starting from (R)-pulegone. The synthesis is considerably more efficient than a previously reported route to rac-agelasine F. ent-Agelasine F is found to exhibit antimicrobial activity. (C) 2008 Elsevier Ltd. All rights reserved.
Synthesis of (+)-striatene: confirmation of its stereostructure
作者:Paul Brémond、Nicolas Vanthuyne、Gérard Audran
DOI:10.1016/j.tetlet.2009.07.138
日期:2009.10
The first enantioselective synthesis of natural striatene (+)-1, isolated from liverwort Ptychanthus striatus, starting from commercially available (R)-Pulegone is described. Its stereostructure was confirmed by X-ray analysis of a 3,5-dinitrobenzoate derivative obtained from a key intermediate and its high optical purity was verified by chiral HPLC. (C) 2009 Elsevier Ltd. All rights reserved.
An efficient synthesis of the natural (+)-fulvanin 1
作者:Philippe Dagneau、Perséphone Canonne
DOI:10.1016/0957-4166(96)00370-9
日期:1996.10
Pulegone was used for the first total synthesis of (+)-fulvanin 1 adopting chiron approach. Pertinent methodology includes stereocontrolled Michael-type reaction, functional group adjustements and Wittig olefination. Copyright (C) 1996 Elsevier Science Ltd