Development of a Robust and Practical Process for the Darzens Condensation and α,β-Epoxide Rearrangement: Scope and Limitations of the Methodology

Abstract

A practical and robust process for the Darzens condensation of substituted benzaldehydes and subsequent α,β-epoxy rearrangement is reported. The process developed is both amenable to large scale and parallel synthesis. While electron-poor benzaldehydes gave mixtures of aryl ketones and 2-substituted aryl ketones in mediocre to low yields, electron-rich benzaldehydes were found to react in high yields with complete regioselectivity to form 2-substituted aryl ketones.

Key words

condensation - rearrangement - regioselectivity - homologation - decarboxylation

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1

Current address: University of Neuchâtel, AV. BelleVaux 51, CP 2, 2007 Neuchâtel, Switzerland; [e-mail].

2

Hirt H., Haenggi R., Reyes J., Seeger-Weibel M., Gallou F.; Org. Process Res. Dev. 2008, 12, 111