The modular protecting-group-free total synthesis of 3-methylkealiiquinone, an analogue of the marine alkaloid kealiiquinone, was accomplished in seven steps. A regioselectively constructed functionalized arylbenzimidazolone moiety and dimethyl squarate were used as the only two building blocks. A thermal ring expansion via 6π-conrotatory ring closure to build the quinone fragment gave rise to the desired linear analogue of the natural compound along with a nondescribed structurally attractive angular naphtho[1,2- d]imidazole regioisomer. The IC values for the compounds were determined on three cancer cell lines.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.joc.8b01436 | DOI Listing |
J Org Chem
January 2025
State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou, 730000 Gansu, P. R. China.
The asymmetric total syntheses of sarglamides A, C, and E in concise and protecting group free fashion is disclosed. Key steps involve an -selective Diels-Alder reaction to construct the bicyclo[2.2.
View Article and Find Full Text PDFOrg Lett
December 2024
Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
We describe a concise asymmetric total synthesis of naturally occurring [5,5]-oxaspirolactone β-levantenolide through an adventitious bromo-spirocyclization reaction of a -decalin appended γ-alkylidenebutenolide. The γ-alkylidenebutenolide core was constructed through "Pd-Cu" bimetallic cascade lactonization reaction of properly functionalized enantiopure alkyne. (+)-Sclareolide was used as a chiral pool starting material to access the desired alkyne.
View Article and Find Full Text PDFOrg Lett
November 2024
The Research Center of Chiral Drugs, Innovation Research Institute of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
J Org Chem
June 2024
Department of Synthetic Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Hoshi University, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
Herein, we report the first protecting group-free total synthesis of (-)-boscartin H, which features a 5-12-5-fused tricyclic structure. The key steps, which include a diastereoselective THF-ring-forming/aldol reaction sequence and ring-closing metathesis, afforded high stereoselectivity with (-)-boscartin H obtained in 3.6% overall yield using a 11-step long linear sequence.
View Article and Find Full Text PDFOrg Lett
April 2024
Department of Chemistry, Aristotle University of Thessaloniki, Main University Campus, Thessaloniki, 54124, Greece.
Natural sesquiterpenoid lactones are prominent scaffolds in drug discovery. Despite the progress made in their synthesis, their extensive oxidative decoration makes their chemo- and stereoselective syntheses highly challenging. Herein, we report our effort to mimic part of the oxidase phase used in the costunolide pathway to achieve the protecting-group-free total synthesis of santamarine, dehydrocostus lactone, estafiatin, and nine more related natural sesquiterpenoid lactones by using dioxygen as the sole oxidant.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!