English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

The mechanism of the formose reaction catalyzed by thiazolium salt was investigated by MOPAC-PM3 semi-empirical molecular orbital (MO) method in order to elucidate the factor(s) stabilizing the reaction intermediates. We assumed that one factor was the formation of an ion pair with the ammonium ion in the reaction medium. Based on this assumption, possible intermediates were examined, including their structures and the heats of formation were calculated. It was suggested that the formation of an ion pair between the zwitterion intermediate (II*) and an ammonium ion and the subsequent formation of the intermediate, 2-hydroxymethyl-3-ethyl-5-(2-hydroxyethyl)-4-methylthiazolium (II**), were crucial for the reaction. A more plausible mechanism for the initial stage of the formose reaction is proposed based on calculation results.

A Computational Study on the Mechanism of the Formose Reaction Catalyzed by the Thiazolium Salt.