ChemInform Abstract: An Asymmetric Synthesis of the Tricyclic Core (I) and a Formal Total Synthesis of Roseophilin (II) via an Enyne Metathesis.

ChemInform ◽  
2010 ◽  
Vol 31 (30) ◽  
pp. no-no
Author(s):  
Barry M. Trost ◽  
George A. Doherty
2018 ◽  
Author(s):  
Marc Montesinos-Magraner ◽  
Matteo Costantini ◽  
Rodrigo Ramirez-Contreras ◽  
Michael E. Muratore ◽  
Magnus J. Johansson ◽  
...  

Asymmetric cyclopropane synthesis currently requires bespoke strategies, methods, substrates and reagents, even when targeting similar compounds. This limits the speed and chemical space available for discovery campaigns. Here we introduce a practical and versatile diazocompound, and we demonstrate its performance in the first unified asymmetric synthesis of functionalized cyclopropanes. We found that the redox-active leaving group in this reagent enhances the reactivity and selectivity of geminal carbene transfer. This effect enabled the asymmetric cyclopropanation of a wide range of olefins including unactivated aliphatic alkenes, enabling the 3-step total synthesis of (–)-dictyopterene A. This unified synthetic approach delivers high enantioselectivities that are independent of the stereoelectronic properties of the functional groups transferred. Our results demonstrate that orthogonally-differentiated diazocompounds are viable and advantageous equivalents of single-carbon chirons<i>.</i>


2014 ◽  
Vol 10 ◽  
pp. 1228-1232 ◽  
Author(s):  
Jens Schmidt ◽  
Zeinab Khalil ◽  
Robert J Capon ◽  
Christian B W Stark

The heronapyrroles A–C have first been isolated from a marine-derived Streptomyces sp. (CMB-0423) in 2010. Structurally, these natural products feature an unusual nitropyrrole system to which a partially oxidized farnesyl chain is attached. The varying degree of oxidation of the sesquiterpenyl subunit in heronapyrroles A–C provoked the hypothesis that there might exist other hitherto unidentified metabolites. On biosynthetic grounds a mono-tetrahydrofuran-diol named heronapyrrole D appeared a possible candidate. We here describe a short asymmetric synthesis of heronapyrrole D, its detection in cultivations of CMB-0423 and finally the evaluation of its antibacterial activity. We thus demonstrate that biosynthetic considerations and the joint effort of synthetic and natural product chemists can result in the identification of new members of a rare class of natural products.


2020 ◽  
Author(s):  
Ronaldo Pilli ◽  
Juliana Lira Luna Freire Regueira ◽  
Luiz Fernando Silva Jr.

This work describes the total synthesis of Raputindole A <b>(1)</b> through a convergent approach which features: 1) an iridium-catalyzed cyclization to assembly the tricyclic core of the northern part, 2) enzymatic resolution to secure the preparation of enantiomerically pure benzylic alcohol, 3) installation of the butenyl substituent via methallylation of the corresponding benzylic carbocation and coupling of the northern and southern parts via Heck reaction. (+)-Raputindole A <b>(1)</b> was prepared in 10 steps (LLS) and 10% overall yield.


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