One-pot synthesis of ethylmaltol from maltol

TL;DR

The paper presents a new one-pot method to synthesize ethylmaltol, a flavor enhancer, from the natural compound maltol.

Contribution

A scalable and operationally simple one-pot synthesis of ethylmaltol using a renewable precursor is introduced.

Findings

A direct methylation approach failed due to overalkylation and low-temperature requirements.

A protecting group strategy enabled selective methylation under mild conditions.

The developed method allows for efficient ethylmaltol synthesis from maltol.

Abstract

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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