Dr. Ravindar Kontham’s Research Group

Welcome to our website! We are a new group of graduate and undergraduate students doing research in the areas of organic synthesis and medicinal chemistry. Our main research focus is on cool projects like practical stereo-selective total synthesis of complex biologically potent natural products and medicinal chemistry. We investigate to prepare more potent, less toxic and structurally simplified analogues of various complex natural products via structural modification of parent natural molecules. We also work on development of new synthetic methodologies involving alkyne cycloisomerization and cascade polycyclizations. 

Natural products have long been regarded as ‘nature’s medicine chest’ providing a rich source of lead compounds as invaluable platforms for developing front-line drugs. 63% of all new drugs approved by the FDA between 1981 and 2006 were inspired by natural products. Our research focuses on making and modifying naturally occurring bioactive compounds that have been isolated from plants, animal tissue, microbes or marine and soil organisms, which are rare or hard to isolate in abundance. These compounds provide rich and diverse chemical structures that challenge the synthetic chemist to develop new flexible synthetic methodology for their construction. The preparation of synthetic analogues of the natural compound may improve the biological activity and provide an understanding of the mechanism of action of the naturally occurring compound.




17th-May-2019 :  Research article of Megha Palange has been accepted in  Org. BiomoCongratulations!

Title: TiCl4-n-Bu3N-mediated cascade annulation of ketones with α-ketoesters: a facile synthesis of highly substituted fused γ alkylidene- butenolides.

Org. Biomol. Chem., 2019, 17, 5749-5759

A facile protocol for the synthesis of highly substituted fused γ-alkylidene butenolides using direct annulation of ketones with α-ketoesters, which proceeds through TiCl4-n-Bu3N mediated aldol addition followed by an intramolecular enol-lactonization/cyclization cascade, is reported.

29th-Mar-2019 :  Research article of Balasaheb Borade has been accepted in  Org. Lett. Congratulations!

Title: Fe(III)-Catalyzed Diastereoselective Friedel–Crafts Alkylation–Hemiketalization–Lactonization Cascade for the Synthesis of Polycyclic Bridged 2-Chromanol Lactones.

Org. Lett, 2019 DOI:10.1021/acs.orglett.9b00614

An unprecedented Fe(III)-catalyzed Friedel−Crafts alkylation−hemiketalization−lactonization cascade of electron-rich hydroxy arenes and distinctively functionalized unsaturated 4-keto esters is developed for the construction of polycyclic bridged 2-chromanol lactones.

4th -Jul-2018 : Navyasree Venugopal Joined as a Ph.D student in Prof. Dr. Ullrich Jahn's research group & Institute of Organic and Bioorganic Chemistry, Prague, Czech Republic.CONGRATULATIONS! 

14th-jun-2018 :  Research article of Sagar S. Thorat and Megha N. Palange has been accepted in  ACS OMEGA Congratulations!

Title : Four steps total synthesis of (+)-Yaoshanenolides A and B

ACS OMEGA, 2018, DOI: 10.1021/acsomega.8b00701

A highly concise bioinspired four-step total synthesis of yaoshanenolides A and B possessing tricyclic spirolactone with an unusual 5′H-spiro-[bicyclo[2.2.2]-oct[2]ene-7,2′-furan]-5′-one scaffold is reported


Dr. Rajesh Nomula selected as a  postdoctoral fellow at university of Strasbourg, France Congratulations!

17th-Apr-2018 :  Research article of Ashwini K. Nakate and Madhukar Pretapure has been accepted in  Org. Biomol. Chem. Congratulations!


Title : Bismuth(III)-catalyzed cycloisomerization and (hetero)arylation of alkynols: a simple access to 2-(hetero)aryl tetrahydrofurans and tetrahydropyrans.


Org. Biomol. Chem, 2018, DOI: 10.1039/C8OB00368H

2-(hetero)aryl tetrahydrofurans and tetrahydropyrans were successfully synthesized using Bi(OTf)3-catalyzed hydroalkoxylation (cycloisomerization) of alkynols (via 5 or 6 exo-dig cyclization) and intermolecular (hetero)arylation.

22nd-Jan-2018:  Research paper of Sagar S. Thorat and Priyanka Kataria has been accepted in  Org. Lett. Congratulations!

Title: Synthesis of Furo[2,3-b]pyran-2-ones through Ag(I) or Ag(I)-Au(I)-Catalyzed Cascade Annulation of Alkynols and  a-Ketoesters


Org.Lett., 2018, 20, 872-875.

Ag(I) or Ag(I)-Au(I)-Catalyzed cascade annulation of alkynols (5-hexyn-1-ol systems) with alpha-ketoesters involving a dual activation process (pi and sigma) has been developed for the first time. This reaction proceeds through cycloisomerization of alkynol to give the 6-endo-enol ether followed by annulation with a-ketoester to furnish furo[2,3-b]pyran-2-ones in good yields.

Title:  Lewis acid catalyzed cascade annulation of alkynols with a-ketoesters: A facile access to gamma-spiroketal-gamma-lactones. 


Chem Commun., 201753, 6641-6644.

A simple protocol for the synthesis of diverse unsaturated g-spiroketal-g-lactones has been developed by employing Bi(OTf)3 catalyzed cascade annulation of alkynols with a-ketoesters via dual (pi and sigma) activation process.


Contact Details:
Dr. Ravindar Kontham
Senior Scientist-CSIR/Asst Professor-AcSIR
Division of Organic Chemistry
CSIR-National Chemical Laboratory
Dr. Homi Bhabha Road
Pune-411008, India.
Phone Office: +91-20-2590 2301
Mobile: +91 750 788 9557
e-mail: k.ravindar@ncl.res.in