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: jens.christoffersuol.de
D. Kieslich, J. Christoffers, Org. Lett., 2021, 23, 953-957.
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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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hydroxylation, oxygen, lactones, isochromanones