A novel stereoselective [8+2] double cycloaddition route to hydronaphthalene ring systems

Area of Science:

• Organic Synthesis
• Cycloaddition Reactions
• Heterocyclic Chemistry

Background:

• Developing efficient synthetic routes for complex organic molecules is crucial in chemistry.
• Tandem reactions offer streamlined pathways to polyfunctionalized compounds.
• Hydronaphthalenes are valuable scaffolds in medicinal chemistry and materials science.

Purpose of the Study:

• To develop a novel synthetic strategy for highly functionalized hydronaphthalenes.
• To explore the utility of dienylfurans and electron-deficient alkynes in cycloaddition reactions.
• To investigate a one-pot, solvent-free approach for synthesizing complex molecular architectures.

Main Methods:

• Employed a tandem [8+2] cycloaddition reaction between dienylfurans and electron-deficient alkynes.
• Utilized a base-catalyzed rearrangement to convert cycloadducts into hydronaphthalenes.
• Performed the reaction under solvent-free conditions in a single reaction flask.

Main Results:

• Successfully synthesized substituted hydronaphthalenes with functionality at each carbon atom.
• Demonstrated the feasibility of a one-pot, solvent-free process, bypassing isolation of sensitive intermediates.
• Proposed a reaction mechanism involving base-catalyzed alkene isomerization and electrocyclic ring closure.

Conclusions:

• The developed tandem cycloaddition-rearrangement strategy provides an efficient route to functionalized hydronaphthalenes.
• Solvent-free conditions enhance the practicality and sustainability of the synthesis.
• The resulting hydronaphthalenes exhibit selective ring-opening and isomerization upon treatment with Lewis acids.