1-Alkoxyvinyl Ester as an Excellent Acyl Donor: Efficient Macrolactone Synthesis

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• Ketene acetal derivatives, including 1-alkoxyvinyl esters and O-silyl ketene acetals, are versatile O-substituted enols of esters.
• These compounds readily react with nucleophiles under neutral conditions to yield acylated and silylated products.
• Traditional synthesis of 1-alkoxyvinyl esters often required mercury salts, hindering their widespread application.

Purpose of the Study:

• To introduce a novel, efficient ruthenium-catalyzed method for synthesizing 1-alkoxyvinyl esters.
• To showcase the application of these novel intermediates in various synthetic transformations.
• To highlight the utility of these methods in the total synthesis of natural products.

Main Methods:

• Development of a ruthenium-catalyzed synthetic route for 1-alkoxyvinyl esters using minimal catalyst loading (0.5-1 mol %).
• Exploration of diverse reactions utilizing 1-alkoxyvinyl esters and their analogs as key intermediates.
• Application of developed synthetic strategies in the stereoselective total synthesis of natural products.

Main Results:

• Successful synthesis of 1-alkoxyvinyl esters using a catalytic amount of a ruthenium complex.
• Demonstration of excellent yields in acylation and silylation reactions via ketene acetal derivatives.
• Achieved the stereoselective total synthesis of fredericamycin A, showcasing the power of the developed methodology.

Conclusions:

• The ruthenium-catalyzed synthesis of 1-alkoxyvinyl esters represents a significant advancement over mercury-based methods.
• The developed synthetic strategies offer broad applicability in organic synthesis, particularly for natural product synthesis.
• Further research has uncovered new reactions and applications for these valuable intermediates.