Synthesis 2022; 54(18): 4095-4103
DOI: 10.1055/a-1835-2188
paper

The Reaction of Ketoximes with Hypervalent Iodine Reagents: Beckmann Rearrangement and Hydrolysis to Ketones

a   School of Pharmaceutical Sciences, Kindai University, 3-4-1 Kowakae, Higashi-osaka, Osaka, 577-8502, Japan
,
Ryohei Oishi
a   School of Pharmaceutical Sciences, Kindai University, 3-4-1 Kowakae, Higashi-osaka, Osaka, 577-8502, Japan
,
Ayumi Maekawa
a   School of Pharmaceutical Sciences, Kindai University, 3-4-1 Kowakae, Higashi-osaka, Osaka, 577-8502, Japan
,
Kazutoshi Segi
a   School of Pharmaceutical Sciences, Kindai University, 3-4-1 Kowakae, Higashi-osaka, Osaka, 577-8502, Japan
,
Hiromi Hamamoto
b   Faculty of Agriculture, Meijo University, 1-501 Shiogamaguchi, Tempaku, Nagoya, 468-8502, Japan
,
a   School of Pharmaceutical Sciences, Kindai University, 3-4-1 Kowakae, Higashi-osaka, Osaka, 577-8502, Japan
c   Research Organization of Science and Technology, Research Center for Drug Discovery and Pharmaceutical Science, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
,
Yasuyoshi Miki
a   School of Pharmaceutical Sciences, Kindai University, 3-4-1 Kowakae, Higashi-osaka, Osaka, 577-8502, Japan
c   Research Organization of Science and Technology, Research Center for Drug Discovery and Pharmaceutical Science, Ritsumeikan University, 1-1-1, Nojihigashi, Kusatsu, Shiga, 525-8577, Japan
› Institutsangaben
This work was financially supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Numbers 19K16329 and 18K05132, and also supported by a 2021 Kindai University Research Enhancement Grant (KD2106).


Abstract

We investigated the reaction of ketoximes with hypervalent iodine reagents. A combination of PhI(OAc)2 and BF3·Et2O promoted the Beckmann rearrangement of ketoximes, thus yielding the corresponding amides. From a detailed investigation of the reaction, we determined that the Beckmann rearrangement is preceded by acetylation of the hydroxy group of the ketoxime in situ, accelerating the Beckmann rearrangement. We confirmed that the acetylated ketoxime undergoes the Beckmann rearrangement with BF3·Et2O. The reaction of ketoximes with Koser’s reagent [PhI(OH)OTs] in the presence of tetrahydrofuran results in hydrolysis, affording the corresponding ketones in high yields at room temperature.

Supporting Information



Publikationsverlauf

Eingereicht: 12. März 2022

Angenommen nach Revision: 26. April 2022

Accepted Manuscript online:
26. April 2022

Artikel online veröffentlicht:
08. Juni 2022

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