1,865,656 research outputs found

    Enantioselective Total Synthesis of (+)-Cassiol

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    An enantioselective total synthesis of (+)-cassiol is reported. The complex derived from Pd-2(pmdba)(3) and enantiopure t-BuPHOX ligand catalyzes enantioconvergent decarboxylative alkylation to generate the quaternary carbon stereocenter at an early stage. The overall synthetic strategy involves a convergent late-stage coupling of two fragments. The synthesis features a longest linear sequence of eight steps

    The Total Synthesis of (ā€“)-Scabrolide A

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    The first total synthesis of the norcembranoid diterpenoid scabrolide A is disclosed. The route begins with the synthesis of two chiral pool-derived fragments, which undergo a convergent coupling to expediently introduce all 19 carbon atoms of the natural product. An intramolecular Dielsā€“Alder reaction and an enoneā€“olefin cycloaddition/fragmentation sequence are then employed to construct the fused [5ā€“6ā€“7] linear carbocyclic core of the molecule and complete the total synthesis

    The first total synthesis of (+)-mucosin

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    The first total synthesis of (+)-mucosin has been completed allowing assignment of the absolute stereochemistry of the natural product. A zirconium induced co-cyclisation was utilised to install the correct stereochemistry of the four contiguous stereocentres around the unusual bicyclo[4.3.0]nonene core

    Enantioselective Total Synthesis of (+)-Salvileucalin B

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    An enantioselective total synthesis of the diterpenoid natural product (+)-salvileucalin B is reported. Key findings include a copper-catalyzed arene cyclopropanation reaction to provide the unusual norcaradiene core and a reversible retro-Claisen rearrangement of a highly functionalized norcaradiene intermediate

    Phyllostictine A : total synthesis, structural verification and determination of substructure responsible for plant growth inhibition

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    The first total synthesis of phyllostictine A (PA) is reported, which confirms the structure of this fungal metabolite and its (6S,7R,8S)-stereochemistry. Both synthetic PA and an analogue containing the 5-methylene-1,5-dihydro-2H-pyrrol-2-one nucleus exhibit Ī¼M inhibitory activity in root growth assays against Arabidopsis thaliana, indicating that this heterocyclic subunit is key to the herbicidal activity of the natural product

    A Concise Total Synthesis of (--)-Maoecrystal Z

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    The first total synthesis of (--)-maoecrystal Z is described. The key steps of the synthesis include a diastereoselective Ti^(III)-mediated reductive epoxide coupling reaction and a diastereoselective Sm^(II)-mediated reductive cascade cyclization reaction. These transformations enabled the preparation of (--)-maoecrystal Z in only 12 steps from (--)-Ī³-cyclogeraniol

    Recent advances in the total synthesis of agelastatins

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    Agelastatins represent an important family of marine alkaloids in terms of both exceptional biological activity and intriguing chemical structure. In this article, the isolation and biological activity of agelastatins are reviewed, and proposed biosynthetic pathways are summarized. The main focus is given to comparative evaluation of recent total syntheses, mainly of agelastatin A. To date, this has been accomplished by 11 research groups. Their synthetic routes are analyzed and summarized, with a view to furnishing the reader with insight into different strategic design approaches to assembly of a densely functionalized and compact structure

    Enantioselective Total Synthesis of (ā€“)-Myrifabral A and B

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    A catalytic enantioselective approach to the Myrioneuron alkaloids (āˆ’)-myrifabral A and (āˆ’)-myrifabral B is described. The synthesis was enabled by a palladium-catalyzed enantioselective allylic alkylation, that generates the C(10) all-carbon quaternary center. A key N-acyl iminium ion cyclization forged the cyclohexane fused tricyclic core, while vinyl boronate cross metathesis and oxidation afforded the lactol ring of (āˆ’)-myrifabral A. Adaptation of previously reported conditions allowed for the conversion of (āˆ’)-myrifabral A to (āˆ’)-myrifabral B
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