@article {49561, title = {Divergent access to α-carbonyl-α'-vinyl sulfoxonium ylides and polysubstituted furans from β-ketosulfoxonium ylides and ynone-esters}, journal = {Journal of Organic Chemistry}, volume = {90}, year = {2025}, month = {APR}, pages = {6186-6207}, type = {Article}, abstract = {

Here, we describe the synthesis of novel alpha-carbonyl-alpha {\textquoteleft}-vinyl sulfoxonium ylides under ambient, catalyst-free, and additive-free conditions, demonstrating broad substrate scope and scalability using beta-ketosulfoxonium ylides and alpha-ynone-esters. Furthermore, these ylides serve as versatile intermediates for the synthesis of highly substituted furans via Br \& oslash;nsted acid (p-TsOH) catalysis at 130 degrees C. This approach offers key advantages, including wide substrate compatibility, divergent product formation from common precursors, gram-scale feasibility, and good to excellent yields.

}, issn = {0022-3263}, doi = {10.1021/acs.joc.5c00245}, author = {Ingale, Sudhir R. and Sahu, Manas Ranjan and Borade, Balasaheb R. and Gamidi, Rama Krishna and Kontham, Ravindar} } @article {49256, title = {The first enantioselective total synthesis of the eremophilane-type sesquiterpenoid (-)-peniroqueforin C}, journal = {Tetrahedron Letters}, volume = {154}, year = {2025}, month = {JAN }, pages = {155386}, type = {Article}, abstract = {

Herein, we report the first stereoselective total synthesis of the eremophilane-type sesquiterpenoid (-)-peniroqueforin C using a chiral-pool strategy. This synthetic route features the use of readily available (S)-(+)-carvone as a chiral building block, Robinson annulation to construct the decalin system, substrate-controlled stereoselective methylation, single-step annulative construction of a tricyclic gamma-ylidene-butenolide with concomitant alkene transposition, and direct lactone-to-lactam conversion as key transformations.

}, keywords = {annulation reactions, Eremophilanes, Peniroqueforin C, Sesquiterpenoids, Total synthesis}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2024.155386}, author = {Ingale, Sudhir R. and Vinodkumar, Ramavath and Kontham, Ravindar} } @article {49500, title = {Total synthesis of linear lipodepsipeptide kavaratamide A and its C25-epimer}, journal = {Organic \& Biomolecular Chemistry}, volume = {23}, year = {2025}, month = {FEB}, pages = {1819-1822}, type = {Article}, abstract = {

We report the stereoselective total synthesis of kavaratamide A, a linear lipodepsipeptide from the cyanobacterium Moorena bouillonii (collected in Kavaratti, India), and its unnatural C25-epimer. The convergent approach employs Keck asymmetric allylation to construct the chiral beta-hydroxy carboxylic acid fragment [(3S)-HDA; 3-hydroxydecanoic acid], while the peptide unit was assembled from l-Val, N-Me-l-Ala, (S)-Hiva, and (S)-iPr-O-Me-pyr using well-orchestrated coupling methods to prevent racemization. Modifications to the Keck allylation conditions enabled the synthesis of the C25-epimer with good yield. Cytotoxicity of kavaratamide A and C25-epi-kavaratamide A, assessed using the MTT assay, demonstrated moderate activity against HepG2 and PANC-1 cell lines.

}, issn = {1477-0520}, doi = {10.1039/d4ob01970a}, author = {Sahu, Manas Ranjan and Ingale, Sudhir R. and Kontham, Ravindar} }