The Petasis-Ferrier rearrangement: developments and applications.

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• The Ferrier-type-II reaction, a carbocycle-generating strategy, was historically limited by its use of toxic stoichiometric mercury salts.
• The reaction involved fragmentation/aldol-type recombination of carbohydrate derivatives.

Purpose of the Study:

• To modernize the Ferrier-type-II reaction, making it more efficient, stereoselective, and environmentally benign.
• To expand the synthetic utility of this rearrangement for organic chemists.

Main Methods:

• Revisiting and updating the Ferrier-type-II reaction conditions.
• Utilizing less toxic promoters for the rearrangement of cyclic vinyl acetals.
• Exploring applications in complex natural product synthesis.

Main Results:

• The Petasis-Ferrier rearrangement effectively converts cyclic vinyl acetals to tetrahydrofurans and tetrahydropyrans with high stereoselectivity.
• Development of a safer, modern variant of the original Ferrier reaction.
• Demonstrated broad applicability in total synthesis and extended scope to in situ substrate generation.

Conclusions:

• The Petasis-Ferrier rearrangement is a powerful and versatile tool in modern organic synthesis.
• Continued innovation has broadened the scope and applicability of this important named reaction.
• The reaction's utility is well-established, particularly in the synthesis of complex natural products.