Synthetic Carbohydrate Chemistry is our main theme of research. More precisely, we are interested in (i) design and synthesis of glycosidase inhibitors (ii) development of newer metho-dologies to functionaliseglycals to obtain highly functionalisedcarbohyd-rate synthons (iii)  development of newer methods for O-; N- and C-glycosylations. Imino and carbasugars form an important class of compounds with interesting structures and immense biological significance, especially as glycosidase inhibitors, making them as important targets for organic synthesis. Synthesis of naturally occurring monocyclic as well bicyclic iminosugars, and design and synthesis of their analogues is of utmost importance, since glycosidase inhibi-tors are useful for the treatment of diseases such as diabetes, Gaucher's disease, Fabry's disease, AIDS, etc. Among the monocyclic iminosugars, numerous  five,  six  and seven membered  compounds,  either naturally occurring or synthetic ones, have been reported in the literature as potent glycosidase inhibitors. Among the bicyclic compounds, indolizidines such as lentiginosine, swainsonine and castanospermine and their analogues are of continued interest, owing to their biological importance and therapeutic value. A few such molecules synthe-sized by us are shown below.

We are also involved in pursuing the chemistry related to functionalisation of glycals and also explore the  chemistry of C-2 substituted glycals with a view to obtain highly functionalised carbohydrates. Among C-2 substituted glycals, we have explored the chemistry of 2-nitroglycals since they have been recognized as important synthons in carbohydrate chemistry in the recent past. This is because of the presence of a conjugated nitroolefin and an enol ether moiety that offer many possibilities of synthetic manipula-tions. For example, such a combination makes these substrates useful for the Michael addition, Diels-Alder reactions, (2+3) cylcoadditions  etc. Besides, the nitro group can be converted to many other useful functionalities such as a carbonyl and an amino group, apart from it being reductively removed. This has led the utilization of 2-nitroglycals as excellent glycosyl donors also. As a consequence, 2-nitroglycals have been utilized in the synthesis of glycoproteins, glycosyl amino acids, and aminosugars via glycosylation as a key step. Besides these, they are used in the synthesis of bicyclic hybrid molecules, fused heterocycles, C-glycosides, 2C-branched sugars etc.  Our aim is to develop new methods to procure 2-nitroglycals and also explore new chemistry related to these molecules. Few synthesised molecules are shown below.

• N-Halosuccinimide/AgNO3:Efficient reagent systems for one step synthesis of 2-halo glycals from glycals: Application in the synthesis of 2C-branched sugars via Heck coupling reactions.
  Org. Lett., 16, 1172 (2014).

• Bicyclic hybrid sugars as glycosidase inhibitors: Synthesis and comparative study of inhibitory activities of fused oxa-oxa, oxa-aza and oxa-carbasugar hybrid molecules,
  J. Org. Chem., 79, 1690 (2014).

• Synthesis of Dihydroxymethyl Dihydroxypyrrolidines and Steviamine Analogues from C-2 Formyl Glycals, 
  J. Org. Chem., 78, 9383 (2013).

• Recent developments in design and synthesis of bicyclic azasugars, carbasugars and related molecules as glycosidase inhibitors,
  Chem. Soc. Revs., 42, 5102 (2013).

• Aza-Claisen rearrangement on 2-C-hydroxymethyl glycals as a versatile strategy towards synthesis of isofagomine and related  biologically important iminosugars.
  Org. Biomol. Chem., 10, 2760 (2012).

• Acetyl Chloride-Silver Nitrate Acetonitrile: A Reagent System for the Synthesis of 2-Nitro-glycals and 2-Nitro-1-Acetamido Sugars from Glycals,  
  J. Org. Chem., 76, 5832 (2011).

• Synthesis of (-)-deoxoprosophylline, (+)-2-epi-deoxoprosopinine and synthesis of (2R, 3R), (2R, 3S)-3-hydroxypipecolic acids from D-glycals.
  J. Org. Chem., 75, 4608 (2010).

• Professor, 1991-Present

• Assistant Professor, 1982-91

• IIT Kanpur: Lecturer, 1981-1982

• Alexander von Humboldt fellow, Universitaet Konstanz, Germany, 1990-91

• Rice University, Houston, 1979-1980

• USC Los Angeles, 1977-1979

• Post-doctoral Fellow, King's College, London, 1976-77

• Distinguished Teacher Award by IIT Kanpur, 2015

• J. C. Bose National Fellowship of DST

• Fellow, Royal Society of Chemistry (UK)

• Fellow, Indian National Science Academy, 2010

• 2013-2016; Fellow, Indian Academy of Sciences, 2002

• Mrs. and Mr. J.S. Bindra Memorial Chair Professor

• S. K. Roy Memorial Chair Professor, 2006-2009

Office

CL 205E ,
Department of Chemistry
IIT Kanpur,
Kanpur 208016

Office Phone: 0512-259-7169 (O)

Email: vankar[AT]iitk.ac.in