Anirban Kar
University of Nantes
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Publication
Featured researches published by Anirban Kar.
Tetrahedron | 2003
Md. Merajuddin Baag; Anirban Kar; Narshinha P. Argade
Abstract N -Bromosuccinimide-dibenzoyl peroxide/azobisisobutyronitrile is used to carry out several types of Z - to E -alkene isomerizations. The NBS-bromination conditions are sufficient for both allylic bromination and alkene isomerization. When the allylic hydrogens are not available in substrates, only the isomerization of the alkene takes place. The present conditions for isomerization of carbon–carbon double bonds are mild and efficient.
Tetrahedron | 2003
Anirban Kar; Narshinha P. Argade
A facile new route to the potential building blocks 2-bromomethyl-3-alkylmaleic anhydrides 15a/b for the synthesis of natural and unnatural dialkylsubstituted maleic anhydrides has been demonstrated, starting from dimethyl citraconate (9) via NBS-bromination, SN2′ Grignard coupling reactions, hydrolysis, molecular bromine addition and dehydrative ring closure reactions pathway with 49–51% overall yield in 5-steps. Chemoselective allylic substitution of bromoatom in 15a/b with Grignard reagents has been described to obtain the unsymmetrical maleic anhydride 16 and symmetrically dialkylsubstituted maleic anhydrides 25a/b in 55% yield. The naturally occurring 2-carboxymethyl-3-hexylmaleic anhydride (1) has been synthesized from 16 via esterification, ozonolysis and an oxidation route. The synthesis of two naturally occurring 2-(β-carboxyethyl)-3-alkylmaleic anhydrides 2a/b have been completed via a chemoselective diethylmalonate coupling reaction followed by acid induced hydrolysis. In our hands the SN2 or SN2′ coupling of Grignard reagent with 21 to obtain 1 and Reformatsky reaction with 15a/b to obtain 2c/d met with failure.
Synthesis | 2005
Anirban Kar; Narshinha P. Argade
A facile 6-step route to (′)-sarkomycin in 17% overall yield has been described via Michael addition of nitromethane to 2-hydroxymethyl-2-cyclopentenone, oxone-induced oxidative Nef reaction, and acid catalyzed dehydration.
Journal of Organometallic Chemistry | 2009
Anirban Kar; Naveenkumar Mangu; Hanns Martin Kaiser; Man Kin Tse
Synthesis | 2005
Anirban Kar; Narshinha P. Argade
Tetrahedron | 2005
Anirban Kar; Sanjib Gogoi; Narshinha P. Argade
Tetrahedron | 2008
Naveenkumar Mangu; Anirban Kar; Anke Spannenberg; Matthias Beller; Man Kin Tse
Synthesis | 2005
Anirban Kar; Narshinha P. Argade
Tetrahedron | 2006
Adjou Ané; Solen Josse; Sebastien Naud; Vivien Lacône; Sandrine Vidot; Anaïs Fournial; Anirban Kar; Muriel Pipelier; Didier Dubreuil
Synthesis | 2004
Anirban Kar; Narshinha P. Argade