Monoallylic 1,3- and 1,5-diols undergo ReO-mediated ionization to form allylic cations that engage in cyclization reactions to form dihydropyran products. The reactions give the 2,6--stereoisomer as the major products as a result of minimizing steric interactions in a boat-like transition state. The results of these studies are consistent with cationic intermediates, with an intriguing observation of stereochemical retention in one example.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.orglett.0c03526 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Synergistic Cu(II)/Amine-Catalyzed Cyclization of Enynone: Assembly of Tetralone and Tetrahydronaphthylimine.
Org Lett
January 2025
School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China.
An unprecedented synergistic copper- and amine-catalyzed cyclization of enynone is reported. This reaction features an efficient and straightforward construction of multisubstituted tetralone through an amine-assisted regioselective oxygen atom transfer process and stereoselective intramolecular Michael addition cyclization. Under dehydrative reaction conditions, the synthesis of tetrahydronaphthylimine derivatives with ketone group tolerance is achieved, which could be challenging via traditional methods.
View Article and Find Full Text PDFHyperspectral imaging for detection of macronutrients retained in glutinous rice under different drying conditions.
Curr Res Food Sci
December 2024
Empa Swiss Federal Laboratories for Material Science and Technology, ETH Zurich, Lerchenfeldstrasse 5, 9014, St. Gallen, Switzerland.
This study detected the macronutrients retained in glutinous rice (GR) under different drying conditions by innovatively applying visible-near infrared hyperspectral imaging coupled with different spectra preprocessing and effective wavelength selection techniques (EWs). Subsequently, predictive models were developed based on processed spectra for the detection of the macronutrients, which include protein content (PC), moisture content (MC), fat content (FC), and ash content (AC). The result shows the raw spectra-based model had a prediction accuracy ( ) of 0.
View Article and Find Full Text PDFAnalysis of morphology, cytotoxicity, and water content characteristics of freeze-dried amnion membrane from human and bovine.
Narra J
December 2024
Department of Polymer Science and Engineering, Chonbuk National University, Jeonju, South Korea.
Placenta tissue has biological advantages, including anti-inflammatory, anti-bacterial, anti-fibrotic formation, and immunomodulatory properties. The amnion membrane (AM) is an inner side membrane of the placenta that faces the fetus. The main sources of amnion are humans and animals, with bovine being one of the significant sources.
View Article and Find Full Text PDFUltrasensitive Specific Detection of Anti-influenza A H1N1 Hemagglutinin Monoclonal Antibody Using Silicon Nanowire Field Effect Biosensors.
ACS Appl Bio Mater
January 2025
Graduate School of Science and Technology, Gunma University, 1-5-1 Tenjin-Cho, Kiryu, Gunma 376-8515, Japan.
Rapid and sensitive detection of virus-related antigens and antibodies is crucial for controlling sudden seasonal epidemics and monitoring neutralizing antibody levels after vaccination. However, conventional detection methods still face challenges related to compatibility with rapid, highly sensitive, and compact detection apparatus. In this work, we developed a Si nanowire (SiNW)-based field-effect biosensor by precisely controlling the process conditions to achieve the required electrical properties via complementary metal-oxide-semiconductor (CMOS)-compatible nanofabrication processes.
View Article and Find Full Text PDFEnvironmental gradients shape genetic variation in the desert moss, Syntrichia caninervis Mitt. (Pottiaceae).
Sci Rep
January 2025
Department of Biological Sciences, California State University Los Angeles, 5151 State University Dr, Los Angeles, CA, 90032, USA.
The moss Syntrichia caninervis Mitt. is distributed throughout drylands globally, and often anchors ecologically significant communities known as biological soil crusts (biocrusts). The species occupies a variety of dryland habitats with varying levels of drought and temperature stress, suggesting the potential for ecological specialization within S.
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!