A set of new bis-spirofused 1,2,4-trioxanes 4a-d was obtained from the reaction of cyclohexane-1,4-dione with allylic hydroperoxides 2a-d, bearing an additional hydroxy group in the homoallylic position, by diastereoselective photooxygenation of allylic alcohols 1a-d and subsequent BF(3)-catalyzed peroxyacetalization with the diketone. From the reaction of a monoprotected cyclohexane-1,4-dione 5 with the allylic hydroperoxide 6 derived from the singlet oxygenation of methyl hydroxytiglate, one monospiro compound was obtained, the 1,2,4-trioxane ketone 7, as well as a mixture of the diastereoisomeric syn- and anti bis-1,2,4-trioxanes 8. The structures of bis-1,2,4-trioxanes were examined theoretically by DFT methods and compared with X-ray structural data in order to evaluate the preferential trioxane ring conformational orientation.
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http://dx.doi.org/10.3390/molecules13081743 | DOI Listing |
Int J Food Sci
December 2024
National Fisheries Development Board, Hyderabad, Telangana, India.
This study investigated the biochemical composition and tested the antioxidant and antimicrobial properties of four Indian-origin essential oils (EOs)-ginger, garlic, clove, and eucalyptus-to evaluate their potential for culinary applications. Gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the chemical constituents of EOs. Antioxidant assays such as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) and antimicrobial assays such as Agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were carried out.
View Article and Find Full Text PDFJ Nutr Sci Vitaminol (Tokyo)
January 2024
Faculty of Pharmaceutical Sciences, Josai International University.
Black rice (BR) is beneficial for the health of animals and humans. Herein, we investigated the pharmacokinetics of cyanidin-3-glucoside (C3G), a major anthocyanin constituent of BR, in male rats. After its intravenous administration, C3G was rapidly distributed throughout the body and disappeared from the plasma.
View Article and Find Full Text PDFSci Bull (Beijing)
December 2024
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200032, China. Electronic address:
Divergent synthesis of valuable molecules through common starting materials and metal catalysis represents a longstanding challenge and a significant research goal. We here describe chemodivergent, highly enantio- and regioselective nickel-catalyzed reductive and dehydrogenative coupling reactions of alkynes, aldehydes, and silanes. A single chiral Ni-based catalyst is leveraged to directly prepare three distinct enantioenriched products (silyl-protected trisubstituted chiral allylic alcohols, oxasilacyclopentenes, and silicon-stereogenic oxasilacyclopentenes) in a single chemical operation.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Wayne State University, Detroit, Michigan 48202, United States.
The utilization of β-fluoroamines as pharmaceutical components for drug development has attracted a considerable amount of interest. However, direct access to tertiary β-fluoroamines is challenging. We herein report the rhodium-catalyzed asymmetric amination of tertiary allylic trichloroacetimidates with anilines and cyclic aliphatic amines to access tertiary β-fluoroamines, where the α-carbon atom is bonded to four different substituents, in good yield with high levels of enantioselectivity.
View Article and Find Full Text PDFChemistry
January 2025
Indian Institute of Technology Kharagpur, Chemistry, Paschim Midnapore, 721302, Kharagpur, INDIA.
All-carbon quaternary and tertiary stereocenters connected at the C2-position of functionalizable C3-alkylated indole nucleus are commonly occurring frameworks found in many indole alkaloids of medicinal importance. Their direct access is scarcely reported, a long-standing problem, and developing a unique yet simple method can pave the pathway to an entirely different retrosynthetic route for the total synthesis of these alkaloids. Herein, this problem is addressed by developing an unprecedented branch-selective allylation strategy employing a broad range of structurally and electronically different 3-alkenyl-indoles and allylboronic acids.
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