@article { ISI:000350763600017, title = {Total and semi-syntheses of antimicrobial thuggacin derivatives}, journal = {Chemistry-A European Journal}, volume = {21}, number = {11}, year = {2015}, month = {MAR}, pages = {4272-4284}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

The total and semi-synthesis of 13 new macrolactones derived from thuggacin, which is a secondary metabolite from the myxobacterium Sorangium cellulosum, are reported. The thuggacins have attracted much attention due to their strong antibacterial activity, particularly towards Mycobacterium tuberculosis. This study focuses on 1) thuggacin derivatives that cannot equilibrate by transacylation between the three natural thuggacins A-C, 2) the roles of the thiazole ring, and 3) the hexyl side chain at C2. Semi-synthetic O-methylation at C17 suppressed the transacylations without a substantial loss of antibacterial activity. Exchanging the C17-C25 side chain for simplified hydrophobic chains led to complete loss of antibacterial activity. Exchange of the thiazole by an oxazole ring or removal of the hexyl side chain at C2 had no substantial effect on the biological properties.

}, keywords = {antibiotics, lactones, Natural products, synthesis design, Total synthesis}, issn = {0947-6539}, doi = {10.1002/chem.201405874}, author = {Franke, Jana and Bock, Martin and Dehn, Richard and Fohrer, Joerg and Mhaske, Santosh B. and Migliorini, Antonella and Kanakis, Argyrios A. and Jansen, Rolf and Herrmann, Jennifer and Mueller, Rolf and Kirschning, Andreas} } @article {45709, title = {Achmatowicz reaction: A versatile tool in bioactive natural products synthesis}, journal = {Current Organic Chemistry}, volume = {21}, year = {2017}, month = {APR}, pages = {503-545}, type = {Article}, abstract = {

Achmatowicz reaction has emerged as an efficient tool in organic synthesis since its discovery in 1971 by Achmatowicz Jr. The original protocol went through several advantageous variations. Biocatalytic and metal catalyzed versions of this reaction are some of the significant achievements, which further enhanced its effectiveness. The pyranone product of the Achmatowicz reaction is a versatile building block for the synthesis of bioactive scaffolds, drugs and natural products. The present review covers the application of the Achmatowicz reaction in the synthesis of natural products and bioactive molecules reported from 1971 to date. It has been divided into seven sections on the basis of the core structures of the natural products synthesized utilizing the Achmatowicz reaction. We believe that this comprehensive review will attract many more organic chemists to explore its utility in organic synthesis, especially in the synthesis of bioactive natural products as well as drugs in their efficient and atom economical synthesis.

}, keywords = {Achmatowicz reaction, carbohydrates, Furanols, Natural products, pyranones, Total synthesis}, issn = {1385-2728}, doi = {10.2174/1385272821666161208154754}, author = {Mahajan, Pankaj S. and Humne, Vivek T. and Mhaske, Santosh B.} } @article {44238, title = {Transition-metal-catalyzed reactions involving arynes}, journal = {Synthesis-Stuttgart}, volume = {50}, year = {2018}, month = {JAN}, pages = {1-16}, type = {Article}, abstract = {

The plethora of transformations attainable by the transition-metal-catalyzed reactions of arynes has found immense contemporary interest in the scientific community. This review highlights the scope and importance of transition-metal-catalyzed aryne reactions in the field of synthetic organic chemistry reported to date. It covers transformations achieved by the combination of arynes and various transition metals, which provide a facile access to a biaryl motif, fused polycyclic aromatic compounds, different novel carbocycles, various heterocycles, and complex natural products. 1 Introduction 2 Insertion of Arynes 3 Annulation of Arynes 4 Cycloaddition of Arynes 5 Multicomponent Reactions of Arynes 6 Miscellaneous Reactions of Arynes 7 Total Synthesis of Natural Products Using Arynes 8 Conclusion

}, keywords = {annulation, arynes, Cycloaddition, Insertion, multicomponent, Natural products, Transition Metal}, issn = {0039-7881}, doi = {10.1055/s-0036-1589517}, author = {Dhokale, Ranjeet A. and Mhaske, Santosh B.} }