1.3‐Dipolare Cycloadditionen, XLIII. Isoxazolidine aus Nitronen mit α.β‐ungesättigten Carbonestern oder Nitrilen

Huisgen, Rolf; Hauck, Hans; Grashey, Rudolf; Seidl, Hildegard

doi:10.1002/cber.19681010736

Cited by 100 publications

(23 citation statements)

References 13 publications

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“…The residue was purified by flash chromatography in petroleum ether/chloroform (1/1 vol.) and dried to obtain 48.7 g (76%) of a yellow colored oil (15). R f -value (CHCl 3 ) = 0.52.…”

Section: Methodsmentioning

confidence: 99%

Polymeric nitrones, 1. Synthesis and modification of polymeric nitrones derived from polymerizable aldehydes

Heinenberg

Ritter²

1999

Macromol. Chem. Phys.

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SUMMARY: The model compound N,C-diphenylnitrone [N-(benzylidene)aniline-N-oxide] (3) was prepared by condensation of benzaldehyde with phenylhydroxylamine to study its thermal stability. X-ray diffraction analysis of a single crystal established the conformation of the nitrone group. A new monomer 4-(methacryloyloxy)benzaldehyde-phenylnitrone (8) was also prepared and could not be polymerized with 2,29-azobisisobutyronitrile (AIBN) as initiator at 70 8C. Under these conditions the nitrone reacted exclusively in an intermolecular 1,3-dipolar cycloaddition to give oligomeric tetrahydro-1,2-oxazoline derivates. The kinetics of the cycloaddition was investigated. Additionally, different (meth)acryl-and styryl-substituted aldehyde monomers were synthesized: (20) and 4-(3-methacryloyloxypropoxy)benzaldehyde (25). These new monomers were homo-and copolymerized with MMA radically at 70 8C using AIBN as initiator. The resulting polyaldehydes 26 -30 were reacted with phenylhydroxylamine to obtain the polynitrones 31 -35 in yields of up to 95%. The obtained highly polar polynitrones 31 -32 were modified by irradiation with UV-light.

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“…The residue was purified by flash chromatography in petroleum ether/chloroform (1/1 vol.) and dried to obtain 48.7 g (76%) of a yellow colored oil (15). R f -value (CHCl 3 ) = 0.52.…”

Section: Methodsmentioning

confidence: 99%

Polymeric nitrones, 1. Synthesis and modification of polymeric nitrones derived from polymerizable aldehydes

Heinenberg

Ritter²

1999

Macromol. Chem. Phys.

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“…The transformation of adducts 25 and 26 into the desired pyrrolizine skeleton requires a simple opening of the isoxazolidine ring by reductive cleavage of the N-O bond, since re-closure to form a lactam moiety by attack of nitrogen to the γ-carboxylic carbon atom occurs spontaneously [23,21]. A mild method consisting of refluxing the isoxazolidine in aqueous acetonitrile in the presence of molybdenum hexacarbonyl has been recently introduced to perform this transformation [24].…”

mentioning

confidence: 99%

A Straightforward Route to Enantiopure Pyrrolizidines and Indolizidines by Cycloaddition to Pyrroline N-Oxides Derived from the Chiral Pool

et al. 1998

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Enantiomerically pure, five membered cyclic nitrones, easily obtained in large amounts from protected hydroxyacids and aminoacids such as D-and L-tartaric, L-malic, and L-aspartic acids, give cycloaddition reactions with a good diastereocontrol. The adducts of L-malic and L-aspartic acids derived from addition of nitrones to dimethyl maleate and γ-crotonolactone were easily converted into enantiopure pyrrolizidinones, which can be transformed into polyhydroxypyrrolidines or polyhydroxypyrrolizidines, both interesting compounds as potential glycosidase inhibitors. The method is suitable for natural products synthesis as exemplified by a straightforward and convenient access to the pyrrolizidine alkaloid necine base (-)-hastanecine, as well as to indolizidine alkaloids, i.e. (+)-lentiginosine.

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“…In the opinion of the authors of [133], azomethine ylides of the (LIX) type, generated from 1,2,3,4-tetrahydroisoquinoline and diarylideneacetone, undergo 1,5-electrocyclization followed by prototropic rearrangement with the formation of compounds ( A similar result was obtained with unsaturated carboxylic acids [135], ethyl propiolate [136], 1,2-di(trifluoromethyl)acetylene [137], and phospholipids [138] as dipolarophiles. In the last case, the reaction takes place through the formation of the aziridines (LXV).…”

Section: XLVIImentioning

confidence: 77%

Pyrrolo[2,1-a]isoquinolines (review)

Михайловский¹,

Shklyaev²

1997

Chem Heterocycl Compd

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1.3‐Dipolare Cycloadditionen, XLIII. Isoxazolidine aus Nitronen mit α.β‐ungesättigten Carbonestern oder Nitrilen

Cited by 100 publications

References 13 publications

Polymeric nitrones, 1. Synthesis and modification of polymeric nitrones derived from polymerizable aldehydes

Polymeric nitrones, 1. Synthesis and modification of polymeric nitrones derived from polymerizable aldehydes

A Straightforward Route to Enantiopure Pyrrolizidines and Indolizidines by Cycloaddition to Pyrroline N-Oxides Derived from the Chiral Pool

Pyrrolo[2,1-a]isoquinolines (review)

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