@article { ISI:000321605900046, title = {Enantioselective total synthesis of desbromoarborescidines A-C and the formal synthesis of (S)-deplancheine}, journal = {Journal of Organic Chemistry}, volume = {78}, number = {13}, year = {2013}, month = {JUL}, pages = {6802-6808}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Starting from Boc-protected tryptamine and (S)-tetrahydro-5-oxo-2-furancarboxylic acid, facile enantioselective total synthesis of desbromoarborescidines A-C and the formal synthesis of (S)-deplancheine have been accomplished via a common intermediate (S)-indolo[2,3-a]quinolizine. Synthesis of enantiomerically pure (S)-acetoxyglutarimide, stereoselective reductive intramolecular cyclization, hydroxyl group assisted in situ N-Boc-deprotection, selective deoxygenation, of the xanthate ester, and lactam hydrolysis followed by an appropriate exchange of nitrogen regioselectivity in intramolecular cyclization were the decisive steps.

}, issn = {0022-3263}, doi = {10.1021/jo401079v}, author = {Mondal, Pravat and N. P. Argade} } @article { ISI:000342568800011, title = {Synthesis of (+)-harmicine}, journal = {Synthesis-Stuttgart}, volume = {46}, number = {19}, year = {2014}, month = {OCT}, pages = {2591-2594}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

A facile convergent access to the important indole alkaloid (+)-harmicine is described, starting from tryptamine and (R)-acetoxysuccinic anhydride via the corresponding acetoxysuccinimide in very good overall yield. Regioselective reduction of an unsymmetrical imide carbonyl group and acid-catalyzed stereoselective intramolecular cyclization were the key features involved. The directing group to induce asymmetry was finally detached via the corresponding iodide by using tributyltin hydride chemistry.

}, keywords = {alkaloids, cyclization, imides, reduction, stereoselective synthesis}, issn = {0039-7881}, doi = {10.1055/s-0034-1378381}, author = {Mondal, Pravat and N. P. Argade} } @article {43626, title = {Stereoselective synthesis of (-)-desethyleburnamonine, (-)-vindeburnol and (-)-3-epitacamonine: observation of a substrate dependent diastereoselectivity reversal of an aldol reaction}, journal = {Organic \& Biomolecular Chemistry}, volume = {14}, year = {2016}, month = {OCT}, pages = {10394-10406}, abstract = {Starting from (-)-acetoxyglutarimide, the enantioselective multistep synthesis of (-)-desethyleburnamonine, (-)-vindeburnol and (-)-3-epitacamonine has been demonstrated via a common hydroxyl-lactam intermediate with very good overall yields. The acetoxy function from (-)-acetoxyglutarimide was initially used as a handle to induce enantioselectivity and then as a latent source of the ketone carbonyl group. Most importantly, substrate dependent reversal of the diastereoselectivity in ester aldol reactions of hexahydroindolo[2,3-a] quinolizinones has been reported.}, doi = {10.1039/c6ob01438k}, author = {Mondal, Pravat and N. P. Argade} } @article {45732, title = {Formal synthesis of bioactive indole alkaloids eburnamonine, eburnaminol, and vindeburnol}, journal = {Synthesis-Stuttgart}, volume = {49}, year = {2017}, month = {APR}, pages = {1849-1856}, type = {Article}, abstract = {

Starting from (+/-)-3-acetoxyglutarimide, diastereoselective formal synthesis of indole alkaloids (+/-)-eburnamonine, (+/-)-eburnaminol, and (+/-)-vindeburnol have been demonstrated via a common intermediate (+/-)-1-hydroxy-12-tosyl-2,3,6,7,12,12b-hexahydroindolo[2,3a] quinolizin-4(1H)-one in very good overall yields. The acetoxy group from (+/-)-3-acetoxyglutarimide was first used to induce the diastereoselectivity and also as a latent source of ketone carbonyl group. The stereoselective eliminations, reductions, and intramolecular cyclizations were the involved key steps.

}, keywords = {cyclizations, eburnaminol, eburnamonine, elimination, hexahydroindoloquinolizinone, reduction, vindeburnol}, issn = {0039-7881}, doi = {10.1055/s-0036-1588386}, author = {Mondal, Pravat and Argade, Narshinha P.} }