One-pot synthesis of ethylmaltol from maltol
Immanuel Plangger1, Marcel Jenny2,3, Gregor Plangger2,3
1Department of Organic Chemistry and Center for Molecular Biosciences, University of Innsbruck, Innrain 80-82, 6020 Innsbruck, Austria.
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A novel route to the flavor enhancer ethylmaltol, a synthetic 4-pyrone, from naturally abundant maltol is disclosed. Two strategies were explored for the required C1 homologation. The most direct approach, C-C bond formation via methylation of a dianionic intermediate, proved unsuitable due to competing overalkylation and the necessity of sub-zero temperatures. In contrast, a transient protecting group approach enabled selective methylation under mild conditions. This culminated in a scalable, operationally simple one-pot synthesis of ethylmaltol from a renewable precursor.
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