17094-36-9Relevant articles and documents
Total synthesis of viridicatumtoxin B and analogues thereof: Strategy evolution, structural revision, and biological evaluation
Nicolaou,Hale, Christopher R. H.,Nilewski, Christian,Ioannidou, Heraklidia A.,Elmarrouni, Abdelatif,Nilewski, Lizanne G.,Beabout, Kathryn,Wang, Tim T.,Shamoo, Yousif
supporting information, p. 12137 - 12160 (2014/11/08)
The details of the total synthesis of viridicatumtoxin B (1) are described. Initial synthetic strategies toward this intriguing tetracycline antibiotic resulted in the development of key alkylation and Lewis acid-mediated spirocyclization reactions to form the hindered EF spirojunction, as well as Michael-Dieckmann reactions to set the A and C rings. The use of an aromatic A-ring substrate, however, was found to be unsuitable for the introduction of the requisite hydroxyl groups at carbons 4a and 12a. Applying these previous tactics, we developed stepwise approaches to oxidize carbons 12a and 4a based on enol- and enolate-based oxidations, respectively, the latter of which was accomplished after systematic investigations that revealed critical reactivity patterns. The herein described synthetic strategy resulted in the total synthesis of viridicatumtoxin B (1), which, in turn, formed the basis for the revision of its originally assigned structure. The developed chemistry facilitated the synthesis of a series of viridicatumtoxin analogues, which were evaluated against Gram-positive and Gram-negative bacterial strains, including drug-resistant pathogens, revealing the first structure-activity relationships within this structural type.
Asymmetric hydrogenation method of a ketonic compound and derivative
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, (2008/06/13)
The present invention relates to a process for the asymmetric hydrogenation of a ketonic compound and derivative. The invention relates to the use of optically active metal complexes as catalysts for the asymmetric hydrogenation of a ketonic compound and derivative. The process for the asymmetric hydrogenation of a ketonic compound and derivative is characterized in that the asymmetric hydrogenation of said compound is carried out in the presence of an effective amount of a metal complex comprising as ligand an optically active diphosphine corresponding to one of the following formulae: STR1
Preparation of acetone dicarboxylic acid diesters
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, (2008/06/13)
Disclosed is a process for preparing an acetone dicarboxylic acid diester, which comprises allowing diketene, carbon monoxide and a nitrous acid ester to react in the presence of a palladium halide or a complex thereof.
