@article { ISI:000244257400014, title = {Practical and facile approach towards indole alkaloids: (-)-mitralactonine}, journal = {Synlett}, number = {1}, year = {2007}, month = {JAN}, pages = {79-82}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

An efficient approach to (-)-mitralactonine using Pictet-Spengler cyclisation with a highly functionalised masked aldehyde is described. Sharpless asymmetric dihydroxylation (SAD) is utilised to introduce chirality in the key substrate.

}, keywords = {alkaloids, asymmetric, cyclisations, dihydroxylations, thioacetats}, issn = {0936-5214}, doi = {10.1055/s-2006-958434}, author = {Chavan, Subhash P. and Sharma, Pallavi and Sivappa, Rasapalli and Kalkote, Uttam R.} } @article { ISI:000250836500003, title = {Total synthesis of (+)-camptothecin via an intramolecular palladium-catalyzed cyclization strategy}, journal = {Synlett}, number = {17}, year = {2007}, month = {OCT}, pages = {2635-2638}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

The novel cascade intramolecular Pd-catalyzed cyclization followed by aromatization for the construction Of D ring of (+)-camptothecin as a key step is demonstrated.

}, keywords = {alkaloids, antitumor, cyclizations, Natural products, Palladium}, issn = {0936-5214}, doi = {10.1055/s-2007-991054}, author = {Chavan, Subhash P. and Pathak, Ashok B. and Kalkote, Uttam R.} } @article { ISI:000261466800007, title = {Tandem aza-michael-condensation-aldol cyclization reaction: approach to the construction of DE synthon of (+/-)-camptothecin}, journal = {Synlett}, number = {18}, year = {2008}, month = {NOV}, pages = {2781-2784}, publisher = {GEORG THIEME VERLAG KG}, type = {Article}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

An efficient synthesis of the DE ring of camptothecin, employing a Reformatsky and a tandem one-pot, three-step transformation involving aza-Michael reaction, condensation with ethyl malonyl chloride followed by intramolecular {\textquoteleft}aldol{\textquoteright} reaction to furnish the dihydropyridone derivative from commercially available starting materials, has been achieved.

}, keywords = {Aldol cyclizations, alkaloids, antitumor, Natural products, Reformatsky reaction}, issn = {0936-5214}, doi = {10.1055/s-0028-1083539}, author = {Chavan, Subhash P. and Dhawane, Abasaheb N. and Kalkote, Uttam R.} } @article {48718, title = {Rapid bioinspired N-acyliminium ion strategy for the ABC core of the stemona alkaloids}, journal = {Asian Journal of Organic Chemistry}, volume = {12}, year = {2023}, month = {SEP}, type = {Article}, abstract = {

A concise and highly diastereoselective bioinspired key cationic cyclization strategy for the asymmetric synthesis of the tricyclic core of the (-)-stemoamide, together with 8,9-bis-epi-stemoamide has been described. The key N-acyliminium ion precursors were accessed from L-tartaric acid and L-malic acid respectively. The use of ethyl acetoacetate derived bifunctional allylidenetriphenylphosphorane reagent in the early stage of the synthetic strategy is advantageous for the rapid construction of highly functionalized key pyrrolo[1,2-\& alpha;]azepine frameworks.

}, keywords = {alkaloids, Biomimetic synthesis, Claisen rearrangement, cyclization, Regioselectivity}, issn = {2193-5807}, doi = {10.1002/ajoc.202300331}, author = {Chavan, Subhash P. and Kalbhor, Dinesh B. and Gonnade, Rajesh G.} }