1 - -3-pyrrolin-2-one

Pyridyl)hydrazine (Aldrich), 4-acetylpyridine (Acros), N,N,N -trimethylethylenediamine (Aldrich), methylrhenium trioxide (Aldrich), InQj (Aldrich), Cu(N0j)2-3H20 (Merck), Ni(N03)2-6Il20 (Merck), Yb(OTf)3(Fluka), Sc(OTf)3 (Fluka), 2-(aminomethyl)pyridine (Acros), benzylideneacetone (Aldrich), and chalcone (Aldrich) were of the highest purity available. Borane dimethyl sulfide (2M solution in THE) was obtained from Aldrich. Methyl vinyl ketone was distilled prior to use. Cyclopentadiene was prepared from its dimer immediately before use. (R)-l-acetyl-5-isopropoxy-3-pyrrolin-2-one (4.15) has been kindly provided by Prof H. Hiemstra (University of Amsterdam). 

Pyrrole oxidizes in air to red or black pigments of uncertain composition. More usehil is the preparation of 2-oxo-A -pyrrolines, which is best carried out by oxidation of the appropriate pyrrole with in pyridine (37), eg, 3,5-dimethyl-ethyl-3-pyrrolin-2-one [4030-24-4] from... 

Pyridazin-3(2H)-ones rearrange to l-amino-3-pyrrolin-2-ones (29) and (30) upon irradiation in neutral methanol (Scheme 10), while photolysis of 5-amino-4-chloro-2-phenylpyridazin-3(2H)-one gives the intermediate (31) which cyclizes readily to the bis-pyridazinopyrazine derivative (32 Scheme 11). 

Poly(imides) — see 3-Pyrroline-2,5-diones Poly(imidines) — see 3-Pyrrolin-2-ones Polyiodides... 

Addition of lithium derivatives of acetylenides (Li—C=C-C02R) to chiral nitrones proceeds with high stereoselectivity, giving a-acetylene substituted hydroxylamines (410a,b) (656). This reaction has been successfully applied to the synthesis of y-hydroxyamino-a, 3-ethylene substituted acids (411a,b), formed in the reduction of (410) with Zn in the presence of acid (657, 658), and to chiral 5-substituted-3-pyrroline-2-ones (412a,b) (Scheme 2.184) (658). 

C27H3oNaOi3 l-Acetyl-3-benzamido-4-(2,3,4,6-tetra-0-acetyl-/3-D-glu-copyranosyloxy)-3-pyrrolin-2-one (ABGPON)123... 

Ultrasound irradiation of mixtures of amines RNH2 (R = PI1CH2, Ph or Ar) and methyl pyruvate results in the 3-pyrrolin-2-ones 322377. The silver tetrafluoroborate-catalysed cyclization of the allenic amines 323 leads either to a pyrroline 324 or tetrahydropyridine 325, depending on the structure of the amine. The former is formed from 323 (R = H), the latter from 323 (R = Me)378. 

Although terrestrial cyanobacteria are well-recognized producers of a wide range of bioactive compounds, marine species have received less attention until recently [159]. One of the most abundant and studied marine cyanobacteria is the pantropic Lyngbya majuscula (Oscillatoriaceae). A prolific producer of metabolites, it has so far yielded more than 110 secondary metabolites including compounds that exhibit antiproliferative, immunosuppressants, antifeedant and molluscidal activities [159,160]. Shallow water varieties of the cyanophyte contain N-substituted amides of 75-methoxytetradec-4E-enoic acid and of 7S-methoxy-9-methylhexa-dec-4 -enoic acid called malyngamides, a sub-class of which contains the 4-methoxy-3-pyrrolin-2-one system [158]. 

Sorangium cellulosum is an ubiquitous soil bacterium that belongs to the order Myxococcales. It has the ability to glide over solid surfaces, to live in a biofilm and form fruiting bodies. Members of this taxon are a particularly rich source of metabolites with remarkable biological activities [177]. From one strain, another example of N-acyl-4-methoxy-3-pyrrolin-2-ones has been isolated. Eliamid (110) has been claimed to have cytostatic, nematocidal and fungicidal activities [178]. 

F. L. Tejero, T. Ready access to enantiopure 5-substituted 3-pyrrolin-2-ones from N-benzyl-2,3-O-isopropylidene-D-glyceraldehyde nitrone. Tetrahedron Asymmetry 1998, 9,1759— 1769. 

The regioselectivity of the 1,3-dipolar cycloadditions of azides to alkenes is usually difficult to predict due to the similar energies for the transition states which involve either the HOMO (dipole) or the LUMO (dipole). The results of a study which utilized 5-alkoxy-3-pyrrolin-2-ones as dipolar-ophiles in reactions with a variety of aryl azides seemed to reflect this problem the results suggested that the low regioselectivity observed was due to the frontier molecular orbital interactions between dipole and dipolarophile, and not any steric hindrance offered by the 5-alkoxy function <84H(22)2363>. 

Jatropham (surely better called jatrophine) is an alkaloid occurring in Jatropha macrorhiza (Euphorbiaceae) which has inhibitory activity towards leukaemia. Its racemic form (4) has been synthesized from 3-methyl-2-furoic acid, as outlined in Scheme l.5 This synthesis vindicates an earlier suggestion that the structure be revised to 5-hydroxy-3-methyl-3-pyrrolin-2-one (4), as opposed to the 4-methyl isomer.6... 

The base-induced cyclization of the precursor 190 to the densely substituted 3-pyrrolin-2-one 191 illustrates an approach to a series of similar products (Equation 57). Other bases, for instance, /-BuOK or K2CO3, also proved to be efficient reagents for such transformations <2006S2019>. 

A base-mediated ring closure of the phenacylamide 192 afforded the 3-pyrroline-2-one 193 (Equation 58), whereas the application of l,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as the reagent at room temperature in acetonitrile provided a route to the corresponding maleimide, demonstrating practical approaches to these types of pyrrole derivatives <2004T3987>. 

Treatment of the aminoketone 243 with lithium trimethylsilyldiazomethane gave the 3-pyrroline 244 (Equation 78). Annulation of related amides provided a corresponding series of 3-pyrroline-2-ones <1996H(42)75>. Likewise, pyrroles may also be obtained upon exposure of N-substituted /3-aminoketones to lithium trimethylsilyldiazomethane <1997SL1063>. 

Taking advantage of an intramolecular Wittig reaction, the a-amidoketones 316 underwent annulation to the 3-pyrrolines 317 upon treatment with the ylide 318 <199581151>. These intermediates could be further elaborated to the pyrroles 319 by base-induced elimination of benzenesulfinic acid (Scheme 37) <2000TL8969>. It should also be mentioned that a set of unusual 3-pyrroline-2-ones have been synthesized by Ugi s four-component reactions from phenacylamine hydrochloride, cyanoacetic acid, cyclohexyl isocyanide, and aldehydes, involving final formation of the C(3)-C(4) bond <1999H(50)463>. 

Heterocyclic stannanes were also employed and yielded 5-acetoxyfuran-2(S/f)-ones and S-acetoxy-1-methyl-3-pyrrolin-2-one from 2-stannylfrirans and 2-stannyl- -methylpyrrole. respectively (Scheme... 

Heterocyclic stannanes were also employed and yielded S-acetoxyfuran-2(S//)-ones and S-acetoxy-1-methyl-3-pyrrolin-2-one from 2-stannylfi s and 2-stannyl-A(-methylpyrTole, respectively (Scheme 8). In the furan system, it appears initial oxidation of the stannane provides the 2-furyl acetate, which is known to undergo further oxidation with LTA (Scheme 8). ... 

A series of 3-pyrrolin-2-ones 6 has been s)mthesized from the readily available oxamates 7 and dimethyl acetylenedicarboxylate (DMAD) in the presence of PPhs <03SC2527>. Unexpectedly, the reaction of thioamides with DMAD involving a 1,3-dipolar cycloaddition of an intermediate azomethine ylide provided a new route to pyrroles <03TL4175>. 

Pyridazine 7V-ethoxycarbonylylides, prepared from pyridazines by N-amination and subsequent treatment with ethyl chloroformate, are transformed photochemically into 1-ethoxycarbony 1-pyrroles (80CPB2676) or 3-pyrrolin-2-one derivatives (85CPB3540). On the other hand, 1,2-bis(carbethoxy)pyridazines are transformed photochemically into 1-ethoxycarbonylpyrrolin-3-ones (87CB1597). 

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