Synthesis of Spirocyclohexadienones with Diverse Structural Types and Ring Sizes.

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Medicinal Chemistry

Background:

• Dearomatization reactions efficiently convert planar aromatic systems into complex 3D molecules.
• Existing methods are limited to specific spirocyclic frameworks (all-carbon, oxa-, aza-) and typically yield only five- or six-membered rings.
• Current strategies offer limited control over ring size diversity.

Purpose of the Study:

• To develop a versatile synthetic strategy for constructing diverse spirocyclic frameworks.
• To overcome limitations in ring size and type accessibility in current dearomatization methods.
• To explore the synthetic utility of novel spirocyclic compounds.

Main Methods:

• Employing iodine-(III)-mediated dearomatization of phenol derivatives.
• Controlling chemo- and regioselectivity through substrate structure, steric effects, and reaction conditions.
• Synthesizing three types of spirocycles, including all-carbon variants in three-, four-, five-, and six-membered rings.

Main Results:

• Successfully synthesized three types of spirocycles with four distinct ring sizes (3-, 4-, 5-, and 6-membered rings).
• Achieved effective chemo- and regioselectivity via strategic modulation of reaction parameters.
• Demonstrated the transformation of products into valuable fused bicyclic ring frameworks.

Conclusions:

• The developed iodine-(III)-mediated dearomatization offers a powerful and versatile approach to spirocycle synthesis.
• This method significantly expands the accessible structural diversity of spirocyclic compounds.
• The resulting functionalized products hold considerable potential for applications in organic synthesis and drug discovery.