Stereochemical studies, 881. Saturated heterocycles, 831 1 Parts 87/82: F. Fülöp, G. Stájer, G. Bernáth, P. Sohár, Tetrahedron, in press. Synthesis of stereoisomeric condensed-skeleton 2-imino-substituted 1,3-oxazines

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Thiourea (1a-d, 2a-d) and urea (3a-d, 4a-d) derivatives have been prepared from cis- and trans-2-aminomethyl-1-cyclopentanols, and -l-cyclohexanols and their N-methyl derivatives with phenyl isothiocyanate and phenyl isocyanate, respectively. Treatment of 1 and 2 with methyl iodide and then with alkali furnished - with the exception of the cis-N-methyl derivative - 2-phenylimino-1,3-oxazines (5a,c, 6a-d). The remarkable fact that the ring closure of trans-2-amino-methyl-1-cyclopentanols gives 1,3-heterocycles with trans-anellation supports the assumption that the trans-1,2-disubstituted-1,3-difunctional cyclopentanes undergo ring closure when 1,3-heterocycles with a delocalized pπ bond system are formed. With thionyl chloride the cis-urea derivatives 3a-d afforded an elimination product (8), whereas the trans isomers 4 yielded the cis oxazines 5 by inversion. 1H and 13C NMR spectroscopic studies indicated that in 5a-d, the "O-in" conformers are favoured (the methylene group of the hetero ring is equatorial, while the oxygen atom is axial) and all 3-unsubstituted-2-phenylimino-1,3-oxazines exist exclusively in the tautomeric form with an exo CN bond.

Original languageEnglish
Pages (from-to)5981-5988
Number of pages8
JournalTetrahedron
Volume41
Issue number24
DOIs
Publication statusPublished - 1985

Fingerprint

Oxazines
Skeleton
Urea
Cyclohexanols
Derivatives
Cyclopentanes
Thiourea
Alkalies
Oxygen
Isomers
Nuclear magnetic resonance
Atoms
cyclopentanol
oxazine 1

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

Cite this

@article{0273f63698e442d98a9132f0f9c6a736,
title = "Stereochemical studies, 881. Saturated heterocycles, 831 1 Parts 87/82: F. F{\"u}l{\"o}p, G. St{\'a}jer, G. Bern{\'a}th, P. Soh{\'a}r, Tetrahedron, in press. Synthesis of stereoisomeric condensed-skeleton 2-imino-substituted 1,3-oxazines",
abstract = "Thiourea (1a-d, 2a-d) and urea (3a-d, 4a-d) derivatives have been prepared from cis- and trans-2-aminomethyl-1-cyclopentanols, and -l-cyclohexanols and their N-methyl derivatives with phenyl isothiocyanate and phenyl isocyanate, respectively. Treatment of 1 and 2 with methyl iodide and then with alkali furnished - with the exception of the cis-N-methyl derivative - 2-phenylimino-1,3-oxazines (5a,c, 6a-d). The remarkable fact that the ring closure of trans-2-amino-methyl-1-cyclopentanols gives 1,3-heterocycles with trans-anellation supports the assumption that the trans-1,2-disubstituted-1,3-difunctional cyclopentanes undergo ring closure when 1,3-heterocycles with a delocalized pπ bond system are formed. With thionyl chloride the cis-urea derivatives 3a-d afforded an elimination product (8), whereas the trans isomers 4 yielded the cis oxazines 5 by inversion. 1H and 13C NMR spectroscopic studies indicated that in 5a-d, the {"}O-in{"} conformers are favoured (the methylene group of the hetero ring is equatorial, while the oxygen atom is axial) and all 3-unsubstituted-2-phenylimino-1,3-oxazines exist exclusively in the tautomeric form with an exo CN bond.",
author = "F. F{\"u}l{\"o}p and G. Bern{\'a}th and P. Soh{\'a}r",
year = "1985",
doi = "10.1016/S0040-4020(01)91438-3",
language = "English",
volume = "41",
pages = "5981--5988",
journal = "Tetrahedron",
issn = "0040-4020",
publisher = "Elsevier Limited",
number = "24",

}

TY - JOUR

T1 - Stereochemical studies, 881. Saturated heterocycles, 831 1 Parts 87/82

T2 - F. Fülöp, G. Stájer, G. Bernáth, P. Sohár, Tetrahedron, in press. Synthesis of stereoisomeric condensed-skeleton 2-imino-substituted 1,3-oxazines

AU - Fülöp, F.

AU - Bernáth, G.

AU - Sohár, P.

PY - 1985

Y1 - 1985

N2 - Thiourea (1a-d, 2a-d) and urea (3a-d, 4a-d) derivatives have been prepared from cis- and trans-2-aminomethyl-1-cyclopentanols, and -l-cyclohexanols and their N-methyl derivatives with phenyl isothiocyanate and phenyl isocyanate, respectively. Treatment of 1 and 2 with methyl iodide and then with alkali furnished - with the exception of the cis-N-methyl derivative - 2-phenylimino-1,3-oxazines (5a,c, 6a-d). The remarkable fact that the ring closure of trans-2-amino-methyl-1-cyclopentanols gives 1,3-heterocycles with trans-anellation supports the assumption that the trans-1,2-disubstituted-1,3-difunctional cyclopentanes undergo ring closure when 1,3-heterocycles with a delocalized pπ bond system are formed. With thionyl chloride the cis-urea derivatives 3a-d afforded an elimination product (8), whereas the trans isomers 4 yielded the cis oxazines 5 by inversion. 1H and 13C NMR spectroscopic studies indicated that in 5a-d, the "O-in" conformers are favoured (the methylene group of the hetero ring is equatorial, while the oxygen atom is axial) and all 3-unsubstituted-2-phenylimino-1,3-oxazines exist exclusively in the tautomeric form with an exo CN bond.

AB - Thiourea (1a-d, 2a-d) and urea (3a-d, 4a-d) derivatives have been prepared from cis- and trans-2-aminomethyl-1-cyclopentanols, and -l-cyclohexanols and their N-methyl derivatives with phenyl isothiocyanate and phenyl isocyanate, respectively. Treatment of 1 and 2 with methyl iodide and then with alkali furnished - with the exception of the cis-N-methyl derivative - 2-phenylimino-1,3-oxazines (5a,c, 6a-d). The remarkable fact that the ring closure of trans-2-amino-methyl-1-cyclopentanols gives 1,3-heterocycles with trans-anellation supports the assumption that the trans-1,2-disubstituted-1,3-difunctional cyclopentanes undergo ring closure when 1,3-heterocycles with a delocalized pπ bond system are formed. With thionyl chloride the cis-urea derivatives 3a-d afforded an elimination product (8), whereas the trans isomers 4 yielded the cis oxazines 5 by inversion. 1H and 13C NMR spectroscopic studies indicated that in 5a-d, the "O-in" conformers are favoured (the methylene group of the hetero ring is equatorial, while the oxygen atom is axial) and all 3-unsubstituted-2-phenylimino-1,3-oxazines exist exclusively in the tautomeric form with an exo CN bond.

UR - http://www.scopus.com/inward/record.url?scp=0022398629&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0022398629&partnerID=8YFLogxK

U2 - 10.1016/S0040-4020(01)91438-3

DO - 10.1016/S0040-4020(01)91438-3

M3 - Article

AN - SCOPUS:0022398629

VL - 41

SP - 5981

EP - 5988

JO - Tetrahedron

JF - Tetrahedron

SN - 0040-4020

IS - 24

ER -