A stereocontrolled approach to alpha-alkyl beta-alkynyl cyclohexanones is reported through a Lewis acid mediated rearrangement reaction of enol ethers bearing an Co-alkyne moiety. The reaction proceeds with high levels of stereoselectivity in the presence of Ti- and B-Lewis acids to provide a range of alpha,beta-disubstituted cyclohexanones in high yield although the products are prone to epimerization at the alpha-position in the presence of the B-promoter system. The potential for an enantioselective variant of this process is outlined, and a rationale for the observed stereochemical trends and detailed structural analyses of the ketone products are described.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/jo0300587 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Selective and Divergent Synthesis of Naphthalene- and Phenanthrene-Fused Azahelicenes by Turning Rearrangement On or Off.
Chemistry
January 2025
Okayama Daigaku Daigakuin Shizen Kagaku Kenkyuka, Division of Applied Chemistry, JAPAN.
The Scholl reaction has been used to synthesize a variety of polycyclic aromatic hydrocarbons, where 1,2-aryl shifts have sometimes occurred to yield unique rearrangement products. However, such 1,2-aryl shifts are often uncontrollable, and the selective and divergent synthesis with or without rearrangement is desired. Here, we achieved the control of the rearrangement in the Scholl reaction of carbazoles by the N-substituents.
View Article and Find Full Text PDFCascade Aza-Prins/Friedel-Crafts Reaction of Homocinnamyloxycarbamate and Aromatic Aldehydes Yielding Aromatic Ring-Annulated Hydrocyclopenta-1,2-oxazinane.
J Org Chem
January 2025
Applied Chemistry and Chemical Engineering, Graduate School of Engineering, Kogakuin University, Nakano 2665-1, Hachioji, Tokyo 192-0015, Japan.
The cascade aza-Prins/Friedel-Crafts reaction of homocinnamyloxycarbamate with electron-rich aromatic aldehydes has been successfully established. Most of the aromatic aldehydes react with the carbamate stereoselectively to generate -hydroindeno-1,2-oxazinanes. However, the cascade reactions of benzaldehydes bearing two methoxy groups at the -positions exhibit a unique stereochemical profile.
View Article and Find Full Text PDFA Phase-Transition-Free Sodium Vanadium Phosphate Cathode via Medium-Entropy Engineering for Superior Sodium Ion Batteries.
Adv Mater
January 2025
Frontiers Science Center for Flexible Electronics (FSCFE), MIIT Key Laboratory of Flexible Electronics (KLoFE), Northwestern Polytechnical University, Xi'an, 710072, China.
NaV(PO), based on multi-electron reactions between V/V/V, is a promising cathode material for SIBs. However, its practical application is hampered by the inferior conductivity, large barrier of V/V, and stepwise phase transition. Herein, these issues are addressed by constructing a medium-entropy material (NaVTiAlCrMnNi(PO), ME-NVP) with strong ME─O bond and highly occupied Na2 sites.
View Article and Find Full Text PDFChemoselectivity in Pd-Based Dyotropic Rearrangement: Development and Application in Total Synthesis of Pheromones.
J Am Chem Soc
January 2025
Laboratory of Synthesis and Natural Products (LSPN), Institute of Chemical Sciences and Engineering, Ecole Polytechnique Fédérale de Lausanne, EPFL-SB-ISIC-LSPN, BCH 5304, CH-1015 Lausanne, Switzerland.
In the dyotropic rearrangement of molecules with semiflexible structures, characterized by a freely rotating static C-C bond, the formation of a mixture of products is common due to the coexistence of several energetically comparable conformers. Herein, we report that it is possible to modulate the shifting groups by adjusting the metal's coordination sphere in Pd-based dyotropic rearrangement. In the presence of a catalytic amount of Pd(II) salt, the reaction of γ-hydroxyalkenes or γ,δ-dihydroxyalkenes with Selectfluor affords fluorinated tetrahydropyranols or 6,8-dioxabicyclo[3.
View Article and Find Full Text PDFInterfacial behavior and emulsifying properties of coconut protein glycated by polygalacturonic acid with different molecular weight.
Int J Biol Macromol
January 2025
School of Food Science and Engineering, Wuhan Polytechnic University,Wuhan 430023, China.
Glycosylation can be used to improve the emulsifying properties of protein by covalently binding with sugar. In this study, we prepared coconut protein (CP) -polygalacturonic acid (PA) conjugates by dry-heat method, studied the effect of PA with different molecular weight on the structure and functionality of CP, and characterized the interfacical behavior of CP at the oil-water interface to establish the relationship between interfacial behavior and emulsion stability. The results showed that different molecular weights of PA (28.
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!