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Formation of δ-Lactones by Cyanide Catalyzed Rearrangement of α-Hydroxy-β-oxoesters

David Kieslich and Jens Christoffers*

*Institut für Chemie, Universität Oldenburg, Carl-von-Ossietzky-Str. 9-11, D-26111 Oldenburg, Germany, Email:

D. Kieslich, J. Christoffers, Org. Lett., 2021, 23, 953-957.

DOI: 10.1021/acs.orglett.0c04157

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A cyanide-catalyzed ring-expansion of cyclic α-hydroxy-β-oxoesters provides δ-valerolactone derivatives in up to quantitative yields. Several alkyl-substituted as well as benzo- and heteroarene-annulated starting materials are converted without problems. As an additional benefit, the substrates are straightforwardly accessed by cerium-catalyzed aerobic α-hydroxylation of readily available β-oxoesters.

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proposed mechanism

Key Words

hydroxylation, oxygen, lactones, isochromanones

ID: J54-Y2021