SYNTHESIS OF 4-(ALKOXYAMINO)CHROMAN-2-ONES <i>via</i> 6-<i>exo</i>-<i>trig</i> CYCLIZATION OF CARBON-CENTERED RADICALS INTO OXIME ETHERS

Authors

  • Carlos A. Bejarano Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Cra. 7 No. 40-62, Edificio Carlos Ortiz, 11001000, Bogotá
  • John E. Díaz Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Cra. 7 No. 40-62, Edificio Carlos Ortiz, 11001000, Bogotá
  • Alix E. Loaiza Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Cra. 7 No. 40-62, Edificio Carlos Ortiz, 11001000, Bogotá

DOI:

https://doi.org/10.1007/2845

Keywords:

4-(alkoxyamino)-2-chromanones, oxime ethers, 6-exo-trig radical cyclizations

Abstract

4-(Alkoxyamino)chroman-2-ones were synthesized via a 6-exo-trig cyclization of alkyl radicals obtained from α-bromoesters containing an oxime ether group. In the case of secondary bromides, the best results were achieved using tris(trimethylsilyl)silane as the chain transfer agent and Et3B as the initiator in dichloromethane at room temperature; the corresponding chromanones were produced in 58–70% yield. Low yields of the cyclized compounds were obtained in the case of tertiary alkyl bromides (20–25%). Products of premature reduction of carbon-centered radicals and addition of ethyl radicals to C=N bond were also observed.

How to Cite
Bejarano, C. A.; Díaz, J. E.; Loaiza, A. E. Chem. Heterocycl. Compd. 2016, 52, 177. [Khim. Geterotsikl. Soedin. 2016, 52, 177.]

For this article in the English edition see DOI 10.1007/s10593-016-1857-z

Author Biographies

Carlos A. Bejarano, Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Cra. 7 No. 40-62, Edificio Carlos Ortiz, 11001000, Bogotá

Bogotá D. C.

John E. Díaz, Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Cra. 7 No. 40-62, Edificio Carlos Ortiz, 11001000, Bogotá

Bogotá D. C.

Alix E. Loaiza, Departamento de Química, Facultad de Ciencias, Pontificia Universidad Javeriana, Cra. 7 No. 40-62, Edificio Carlos Ortiz, 11001000, Bogotá

Bogotá D. C.

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Published

2016-03-15

Issue

Vol. 52 No. 3 (2016)

Section

Original Papers