Photocatalytic delayed hydration by alkene-alkene coupling: Modular access to highly substituted γ- and δ-lactones

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Photocatalysis

Background:

• Gamma- and delta-lactones are crucial structural motifs in natural products and bioactive compounds.
• Existing synthetic methods often lack efficiency and tunability for accessing diverse lactone structures.

Purpose of the Study:

• To develop a rapid and modular photocatalytic strategy for synthesizing gamma- and delta-lactones.
• To enable the assembly of lactones from readily available alkenes and water.

Main Methods:

• A photocatalytic "streamlined sew" strategy involving [1+2+2] or [1+2+3] cyclization of two alkenes with water.
• Utilized delayed alkene hydration via differentiated alkyl radicals for chemo- and regioselective cross-coupling.

Main Results:

• Successfully synthesized gamma- and delta-lactones from two distinct alkene precursors.
• Demonstrated tolerance for various alkene substrates, including styrenes and substituted aliphatic alkenes.
• Achieved rapid and modular assembly of lactone structures.

Conclusions:

• The developed photocatalytic method provides efficient access to gamma- and delta-lactones.
• This strategy offers a tunable and modular approach for synthesizing diverse lactone derivatives from simple starting materials.