Can I read Photo-induced rearrangement of isoxazolines - A pathway to 2,4,5,8-tetrahydro-1,3-dioxa-5-azocine derivatives on EtoBox?

Photo-induced rearrangement of isoxazolines - A pathway to 2,4,5,8-tetrahydro-1,3-dioxa-5-azocine derivatives by Fišera, Lubor; Oremus, Vladimír; Štibrányi, Ladislav; Timpe, Hans-Joachim; Máťušová, Alena is a Chemistry article available to read on EtoBox.

What is Photo-induced rearrangement of isoxazolines - A pathway to 2,4,5,8-tetrahydro-1,3-dioxa-5-azocine derivatives about?

4-R-Substituted-8-X-phenyl-3,5,10-trioxa-9-azabicyclo[3,5,0]dec-8-enes (X = H, 4-CH3, 4-OCH3, 4-Cl, 4-Br, 4-F, 3-NO2, 3-Cl, 3-Br) have been prepared by cycloaddition of substituted benzenenitriloxides with 2-R-substituted 1,3-dioxep-5-enes (R = H, CH3, C6H5). A mixture of the endo and exo adducts is formed, if R is CH3 or C6H5. Their irradiation produces high yields of the title compounds as the single products. High selectivity of the photo-rearrangement is due to resonance stabilization of the biradical with p electrons of the oxygen atom. The quantum yields of the photoreaction vary from 0.02 to 0.04 depending on the substituent X. An unexpected dependence has been found between the quantum yield of the photo-rearrangement and stereochemical arrangement of the 4-R-substituent: exo derivatives exhibit higher values than the endo derivatives. Also different are UV spectra of the endo and exo derivatives. A new synthesis principle is described enabling preparation of (n + 1)-membered heterocycles from n-membered heterocycles.

Who reads Photo-induced rearrangement of isoxazolines - A pathway to 2,4,5,8-tetrahydro-1,3-dioxa-5-azocine derivatives?

Author

Fišera, Lubor; Oremus, Vladimír; Štibrányi, Ladislav; Timpe, Hans-Joachim; Máťušová, Alena

Publisher

UOCHB; Institute of Organic Chemistry & Biochemistry, Academy of Sciences of the Czech Republic; Akademie Ved Ceske Republiky; Institute of Organic Chemistry & Biochemistry (ISSN 0010-0765)

Published

1985

Language

EN

Field

Chemistry (Physical Sciences)