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Ring Closure Reaction (ring + closure_reaction)

Distribution by Scientific Domains
Chemistry85%

Selected Abstracts

ChemInform Abstract: Indium(I) Bromide Promoted Stereoselective Preparation of Cyclopropanes via Sequential Aldol-Type Coupling/Elimination/Michael-Induced Ring Closure Reaction from ,,,-Dichloroacetophenone and Aldehydes.

CHEMINFORM, Issue 11 2009
Clovis Peppe
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Thermal Ring Closure Reaction of 4-Methyl-7-(1,1-disubstituted propyne-2-yloxy)chromen-2-ones: The Effects of the Substituents at Propargylic Position on Reactivity and Products.

CHEMINFORM, Issue 21 2005
Qian Zhang
Abstract For Abstract see ChemInform Abstract in Full Text. [source]

ChemInform Abstract: Palladium-Mediated Ring Closure Reactions.

CHEMINFORM, Issue 2 2001
Facile Syntheses of Enantiopure Bicyclic, Tricyclic Alkenones.
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

ChemInform Abstract: Ring Closure Reactions of Disubstituted 4-Penten-1-oxyl Radicals , Towards a Stereoselective Synthesis of allo-Muscarine.

CHEMINFORM, Issue 1 2001
Jens Hartung
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

tert -Amino effect at a coumarin and a 2-quinolone system: Synthesis of 1,2 fused 5H -chromeno[4,3- b]pyridin-5-ones and a 6H -benzo[h][1,6]naphthyridin-5-one

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 1 2008
Ivo C. Ivanov
Some novel 1,2-fused 5H -chromeno[4,3- b]pyridin-5-ones (5a,b) and a 6H -benzo[h][1,6]naphthyridin-5-one (5c) have been synthesized starting from the 4-chlorocoumarin-3-carbaldehyde (1a) or its N -methyl-2-quinolone analogue (1b) via subsequent Knoevenagel condensation and ring closure reaction known as the ,tert -amino effect'. These are rare examples of the tert -amino effect occurring at 2-pyrone and 2-pyridone ring. An unusual intramolecular redox reaction of the iminium ion 6, reported earlier, most probably follows analogous mechanism as the tert- amino effect reactions leading to 5. [source]

The unexpected rearrangement of 1,5-benzodiazepin-2,4-dione to a benzimidazol-2-one derivative during N,N' -diglucosylation

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 6 2004
Brahim Lakhrissi
Reaction of 1,5-benzodiazepin-2,4-dione with 3- O -substituted-5,6-anhydro-1,2-isopropylidene-,-D-glucofuranose gave the unexpected N,N' -di-glucofuranosyl benzimidazol-2-one by a novel rearrangement and ring closure reaction. A mechanism is proposed. [source]

Benzoxazine containing polyester thermosets with improved adhesion and flexibility

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 19 2010
Alev Tuzun
Abstract High molecular weight polyesters containing thermally curable benzoxazine units in the main chain have been synthesized. For this purpose, first the diol functional monomer is synthesized through the Mannich and subsequent ring closure reactions of bisphenol-A, paraformaldehyde, and 5-amino-1-pentanol. Polycondensation of the resulting benzoxazine and pyromellitic dianhydride or 4-4,-(hexafluoroisopropylidene) diphatalic anhydride with or without dibutyltin laurate yielded the corresponding polyesters with the molecular weights between 5800 and 7000 Da. The structures of the precursor diol monomer and the resulting polyesters are confirmed by Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy analysis. Curing behavior of both the monomer and polymers has also been studied by differential scanning calorimetry. Flexible films of the polyesters were obtained by solvent casting on tin plates and crosslinked by heating in the absence of any catalyst. The cured films exhibited high flexibility and adhesion on the tin plates as determined by ASTM and DIN tests. Thermal properties of the cured polymers were also investigated by thermogravimetric analysis (TGA). © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4279,4284, 2010 [source]