Transmissive olefination route to putative "morinol I" lignans

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Lignan Synthesis

Background:

• Morinol-type lignans are a class of natural products with potential biological activities.
• Efficient and stereoselective synthesis of these complex molecules remains a challenge.

Purpose of the Study:

• To develop a rapid and stereoselective synthetic strategy for morinol-type lignans and their analogues.
• To establish a new method for controlling E/Z stereoselectivity in alkenemethanol synthesis.

Main Methods:

• Grignard-based transmissive olefination for rapid assembly of lignan scaffolds.
• Palladium-catalyzed arylations for introducing structural diversity.
• A novel method for converting alkenenitriles to alkenemethanols to control E/Z selectivity.

Main Results:

• Stereoselective synthesis of (7Z,7'E), (7E,7'E), and (7E,7'Z) morinol diastereomers.
• Access to (7Z,8'E) and (7E,8'E) conjugated morinol analogues.
• Demonstrated circumvention of enal E/Z isomerization in alkenemethanol synthesis.

Conclusions:

• The developed strategy provides efficient and stereoselective access to diverse morinol-type lignans.
• The new alkenenitrile to alkenemethanol conversion is crucial for controlling E/Z stereoselectivity.
• This work expands the synthetic toolbox for lignan chemistry.