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Updated: Jan 19, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
A computational study of radical haloacetal cyclizations controlled by the acetal center
Olivier Corminboeuf1, Philippe Renaud, Carl H Schiesser
1Department of Chemistry and Biochemistry, University of Bern Freiestrasse 3, Switzerland.
Abstract:
The stereochemical outcome of the radical haloacetal cyclization reaction (Ueno-Stork reaction) has been examined by ab initio and other molecular orbital techniques. It was found that the stereochemistry of 5-exo- and 6-exo trig cyclizations can be accurately predicted from calculations using moderate levels of theory (UHF/6-311G** or B3LYP/6-311G**). A simplified computational procedure, easily run on a standard desktop computer, has been developed that provides excellent predictive ability for the stereochemical outcome for the reactions in question. Interestingly, a novel twist transition state has been identified for the first time in 5-exo-trig radical cyclization reactions.
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