saturated heterocycles, 133. Nitrilimine and nitrile oxide cycloaddition to cis-condensed 1,3-dihydrooxazines

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Abstract

cis-5,6-Tetramethylene-4H-1,3-dihydrooxazine (1) and an analogue unsaturated in the carbocyclic ring (2) give adducts at the heterodouble bond with diphenylnitrilimine or benzonitrile oxide, furnishing 1,3-oxazino-1,2,4-triazolines (3 and 4) or oxadiazolines 5 and 6), respectively. The site-selectivity of the cycloaddition differs from that of the earlier studied norbornene-condensed dihydrooxazines, where the nitrile oxide dipole attacks first the CC and not the CN bond. The conformation of the oxazine rings, the annelation of the hetero rings and the configuration at C-3a have been elucidated by 1H and 13C n.m.r. spectroscopy and for 4 by X-ray analysis. The crystallographic data show that the hetero rings are cis-fused, in accordance with the conclusions inferred from the n.m.r. spectra. The lone pair of the pyramidal N(10) atom is eclipsed with the 3a-aryl ring.

Original languageEnglish
Pages (from-to)5461-5466
Number of pages6
JournalTetrahedron
Volume43
Issue number22
DOIs
Publication statusPublished - 1987

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Nitriles
Cycloaddition
Cycloaddition Reaction
Oxides
Oxazines
X ray analysis
Conformations
Spectrum Analysis
X-Rays
Spectroscopy
Atoms
benzonitrile
2-norbornene

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

Cite this

@article{acaaf2142cdf4fd1b6faf76163296a5e,
title = "saturated heterocycles, 133. Nitrilimine and nitrile oxide cycloaddition to cis-condensed 1,3-dihydrooxazines",
abstract = "cis-5,6-Tetramethylene-4H-1,3-dihydrooxazine (1) and an analogue unsaturated in the carbocyclic ring (2) give adducts at the heterodouble bond with diphenylnitrilimine or benzonitrile oxide, furnishing 1,3-oxazino-1,2,4-triazolines (3 and 4) or oxadiazolines 5 and 6), respectively. The site-selectivity of the cycloaddition differs from that of the earlier studied norbornene-condensed dihydrooxazines, where the nitrile oxide dipole attacks first the CC and not the CN bond. The conformation of the oxazine rings, the annelation of the hetero rings and the configuration at C-3a have been elucidated by 1H and 13C n.m.r. spectroscopy and for 4 by X-ray analysis. The crystallographic data show that the hetero rings are cis-fused, in accordance with the conclusions inferred from the n.m.r. spectra. The lone pair of the pyramidal N(10) atom is eclipsed with the 3a-aryl ring.",
author = "G. St{\'a}jer and G. Bern{\'a}th and Szab{\'o}, {Angela E.} and P. Soh{\'a}r and G. Argay and A. K{\'a}lm{\'a}n",
year = "1987",
doi = "10.1016/S0040-4020(01)87728-0",
language = "English",
volume = "43",
pages = "5461--5466",
journal = "Tetrahedron",
issn = "0040-4020",
publisher = "Elsevier Limited",
number = "22",

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TY - JOUR

T1 - saturated heterocycles, 133. Nitrilimine and nitrile oxide cycloaddition to cis-condensed 1,3-dihydrooxazines

AU - Stájer, G.

AU - Bernáth, G.

AU - Szabó, Angela E.

AU - Sohár, P.

AU - Argay, G.

AU - Kálmán, A.

PY - 1987

Y1 - 1987

N2 - cis-5,6-Tetramethylene-4H-1,3-dihydrooxazine (1) and an analogue unsaturated in the carbocyclic ring (2) give adducts at the heterodouble bond with diphenylnitrilimine or benzonitrile oxide, furnishing 1,3-oxazino-1,2,4-triazolines (3 and 4) or oxadiazolines 5 and 6), respectively. The site-selectivity of the cycloaddition differs from that of the earlier studied norbornene-condensed dihydrooxazines, where the nitrile oxide dipole attacks first the CC and not the CN bond. The conformation of the oxazine rings, the annelation of the hetero rings and the configuration at C-3a have been elucidated by 1H and 13C n.m.r. spectroscopy and for 4 by X-ray analysis. The crystallographic data show that the hetero rings are cis-fused, in accordance with the conclusions inferred from the n.m.r. spectra. The lone pair of the pyramidal N(10) atom is eclipsed with the 3a-aryl ring.

AB - cis-5,6-Tetramethylene-4H-1,3-dihydrooxazine (1) and an analogue unsaturated in the carbocyclic ring (2) give adducts at the heterodouble bond with diphenylnitrilimine or benzonitrile oxide, furnishing 1,3-oxazino-1,2,4-triazolines (3 and 4) or oxadiazolines 5 and 6), respectively. The site-selectivity of the cycloaddition differs from that of the earlier studied norbornene-condensed dihydrooxazines, where the nitrile oxide dipole attacks first the CC and not the CN bond. The conformation of the oxazine rings, the annelation of the hetero rings and the configuration at C-3a have been elucidated by 1H and 13C n.m.r. spectroscopy and for 4 by X-ray analysis. The crystallographic data show that the hetero rings are cis-fused, in accordance with the conclusions inferred from the n.m.r. spectra. The lone pair of the pyramidal N(10) atom is eclipsed with the 3a-aryl ring.

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U2 - 10.1016/S0040-4020(01)87728-0

DO - 10.1016/S0040-4020(01)87728-0

M3 - Article

VL - 43

SP - 5461

EP - 5466

JO - Tetrahedron

JF - Tetrahedron

SN - 0040-4020

IS - 22

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