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Updated: Jun 2, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Synthesis of the purported ent-pochonin J structure featuring a stereoselective oxocarbenium allylation
Dionicio Martinez-Solorio1, Kenneth A Belmore, Michael P Jennings
1Department of Chemistry, The University of Alabama, 250 Hackberry Lane, Tuscaloosa, Alabama 35487-0336, United States.
Abstract:
The synthesis of the alleged natural product pochonin J is presented. Key steps of this convergent synthesis include a chemoselective Wacker oxidation, and an Evans' anti-reduction of the resulting ketone. Upon ozonolysis, this intermediate undergoes a 6-exo-trig cyclization to give a hemiketal intermediate, the key oxocarbenium precursor. The construction of the α-C-glycoside subunit is highlighted by a mismatched oxocarbenium cation formation/allylation sequence. An olefin metathesis afforded the 14-membered macrolactone, and final oxidation provided the "desired" compound that does not spectroscopically correlate to the initially described natural product.
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