Methods have been developed for regio- and stereoselective 1,4-syn or 1,4-anti methylation of seven-membered epoxyvinylsulfones. 1,4-Syn addition is achieved via the combination of Me(2)Zn and catalytic Li(2)CuCl(4), a hitherto unexplored reagent combination. The complementary 1,4-anti addition relies on Cu(I) catalyzed methyl Grignard addition or (CH(3))(3)Al assisted CH(3)Cu addition. The methods described were assayed on four diastereomeric stereodiads and on their parent epoxide.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ja9017557 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Talarmalnoids A-F: Fusicoccane diterpenoids from an arthropod-derived endophytic fungus Talaromyces malicola.
Fitoterapia
December 2024
State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China. Electronic address:
The metabolites from the endophytic fungus Talaromyces malicola hosted in the gastrointestinal tract of the arthropods Armadillidium vulgare were investigated, and six undescribed fusicoccane diterpenoids, talarmalnoids A-F (1-6), along with three known analogs were isolated. Talarmalnoid C (3) was an unprecedented fusicoccane diterpenoid with two sugar units, i.e.
View Article and Find Full Text PDFDizocilpine derivatives as neuroprotective NMDA receptor antagonists without psychomimetic side effects.
Eur J Med Chem
December 2024
Institute of Experimental Medicine of the Czech Academy of Sciences, Videnska 1083, 4, 14220, Prague, Czech Republic. Electronic address:
We aimed to prepare novel dibenzo [a,d][7]annulen derivatives that act on N-methyl-d-aspartate (NMDA) receptors with potential neuroprotective effects. Our approach involved modifying the tropane moiety of MK-801, a potent open-channel blocker known for its psychomimetic side effects, by introducing a seven-membered ring with substituted base moieties specifically to alleviate these undesirable effects. Our in silico analyses showed that these derivatives should have high gastrointestinal absorption and cross the blood-brain barrier (BBB).
View Article and Find Full Text PDFRing Expansion via One-Pot Conversion of Lactone Acetals to Cyclic Enones. Synthesis of (±)-1--Xerantholide.
Org Lett
October 2024
Department of Chemistry and Biochemistry, California State University, Northridge, 18111 Nordhoff Street, Northridge, California 91330-8262, United States.
Baeyer-Villiger oxidation of α-alkoxy ketones provides lactone acetals , which react with the lithium salts of dimethyl(alkyl) phosphonates in the presence of LaCl·2LiCl to provide cyclic enones in good to excellent yields after treatment with dilute aqueous potassium carbonate. Thus, five-, six-, and seven-membered lactones are converted to five-, six-, and seven-membered cyclic enones. The utility of this two-step ring expansion method is demonstrated in the synthesis of (±)-1--xerantholide from 5-methyl-2-cyclohexen-1-one.
View Article and Find Full Text PDFStructural determination of oleanane-28,13β-olide and taraxerane-28,14β-olide fluoro-lactonization products from the reaction of oleanolic acid with Selectfluor.
Acta Crystallogr E Crystallogr Commun
August 2024
Department of Chemistry, University of Manchester, Manchester, United Kingdom.
The X-ray crystal structure data of 12-α-fluoro-3β-hy-droxy-olean-28,13β-olide methanol hemisolvate, 2CHFO·CHOH, (), and 12-α-fluoro-3β-hy-droxy-taraxer-28,14β-olide methanol hemisolvate, 2CHFO·CHOH, (), are described. The fluoro-lactonization of oleanolic acid using Selectfluor yielded a mixture of the six-membered δ-lactone () and the unusual seven-membered γ-lactone () following a 1,2-shift of methyl C-27 from C-14 to C-13.
View Article and Find Full Text PDFRole of the hydrocarbon molecular structure in CNT growth on Fe-Al catalysts.
Phys Chem Chem Phys
July 2024
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu, P. R. China.
Upgrading plastic wastes into high-value products the thermochemical process is one of the most attractive topics. Although carbon nanotubes (CNTs) have been successfully synthesized from plastic pyrolysis gas over Fe-, Co-, or Ni-based catalysts, a deep discussion about the reaction mechanism was seldom mentioned in the literature. Herein, this work was intended to study the growth mechanism of CNTs from hydrocarbons on Fe-AlO catalysts.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!