Direct α-Benzylation of Methyl Enol Ethers with Activated Benzyl Alcohols: Its Rearrangement and Access to (±)-Tetrahydronyasol, Propterol A, and 1,3-Diarylpropane.

Abstract

Herein, we report a one-pot Lewis acid mediated synthesis of bi- and triarylpropanal derivatives and their corresponding isomeric ketones from aromatic enol ethers. This transformation takes place via nucleophilic attack of enol ethers to electron-rich benzyl alcohols. The substrate scope of this indicates that it might proceed via quinomethoxy methide as a key intermediate leading to propanal derivatives, and their Wagner-Meerwein rearrangement afforded isomeric ketones. Further, this methodology was applied for the synthesis of (±)-tetrahydronyasol, propterol A, and 1,3-diarylpropane.