Isolation and synthesis of biologically active carbazole alkaloids

Generating diverse structures with a minimum amount of synthetic effort is an important goal for drug discovery. Here, the authors report a two-phase synthesis for the generation of skeletally diverse small molecules—forming molecular scaffolds and subsequently diversifying each into multiple structures.

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De novo branching cascades for structural and functional diversity in small molecules

The synthesis of carbocyclic eight-membered rings

Progress in the construction of cyclooctanoid systems: new approaches and applications to natural product syntheses.

Nitrones are important compounds and are highly useful in many aspects. The first part describes the methods for synthesis of nitrones, which are useful and environmentally friendly. Catalytic oxidations, condensations, and other useful reactions are described. The nitrones thus obtained are key intermediates for the synthesis of biologically important nitrogen compounds. The second part describes the fundamental transformations of nitrones, which will provide the strategies and means for the construction of nitrogen compounds. The reactions with nucleophiles or radicals, C–H functionalization, and various addition reactions are described. The last reactions are particularly important for highly selective carbon—carbon bond formations. 1,3-Dipolar cycloaddition reactions are excluded because the size of the review is limited and excellent reviews have been published in Chemical Reviews.

/pdf/synthesis-and-transformations-of-nitrones-for-organic-45nqssi8wz.pdf

Synthesis and Transformations of Nitrones for Organic Synthesis

Hetero-cope rearrangements - vI1 short and stereoselective syntheses of 2-vinylindoles by a tandem-process

Stereoselective Synthesis of Taxane Derivatives



Substituted racemic 4,8,12-trinortaxanes were prepared stereoselectively in several steps from the dienone 10. A variant of the de Mayo reaction with bicyclononenones 4 and cyclohexen produced the desired configuration at C(8) of the taxane framework. Retro-aldol cleavage of the tetracycle 5 led to the taxane skeleton 6. Stereoselective reduction followed by treatment with base afforded 7b. Hydrolysis of the acetal group and further reduction yielded 9 in which the relative configuration corresponds to the one of the natural products.

Andrea Kühling

Papers

Hetero-cope rearrangements - vI1 short and stereoselective syntheses of 2-vinylindoles by a tandem-process

Stereoselektive Synthesen von Taxan‐Derivaten