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R Raghunathan - One of the best experts on this subject based on the ideXlab platform.
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6a nitro 6 2 2 7 7 tetra methyl tetra hydro 3ah bis 1 3 dioxolo 4 5 b 4 5 d pyran 5 yl 6a 6b 7 8 9 11a hexa hydro 6h spiro chromeno 3 4 a Pyrrolizine 11 11 indeno 1 2 b quinoxaline
Acta Crystallographica Section E-structure Reports Online, 2014Co-Authors: T Anuradha, P R Seshadri, R RaghunathanAbstract:In the title compound, C39H38N4O8, the quinoxaline and indene subunits are essentially planar, with maximum deviations of 0.071 (2) and 0.009 (2) A, respectively. The indenoquinoxaline system forms a dihedral angle of 72.81 (3)° with the chromenoPyrrolizine system. The two dioxolane rings, as well as the pyran ring of the chromeno group and the terminal Pyrrolizine, each adopt an envelope conformation with O and C as flap atoms. The central Pyrrolizine ring adopts a twisted conformation. Intramolecular C—H⋯O and C—H⋯N hydrogen bonds occur. The crystal structure exhibits C—H⋯O hydrogen bonds, and is further stablized by C—H⋯π interactions, forming a two-dimensional network along the bc plane.
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ethyl 1r 1 s 2 s 7a r 2 oxo 1 3ar 5r 5as 8as 8br 2 2 7 7 tetra methyl tetra hydro 3ah bis 1 3 dioxolo 4 5 b 4 5 d pyran 5 yl 1 2 5 6 7 7a hexa hydro 2h spiro acenaphthyl ene 1 3 Pyrrolizine 2 carboxyl ate
Acta Crystallographica Section E-structure Reports Online, 2012Co-Authors: G Jagadeesan, K Sethusankar, R Prasanna, R RaghunathanAbstract:In the title compound, C32H37NO8, the central pyran ring adopts a twist-boat conformation and the 1,3-dioxoane rings adopt envelope conformations. The acenaphthylenone unit and two C atoms of a pyrrolidine ring are disordered over two sets of sites [occupancy ratio 0.669 (7):0.331 (7)]. The major fraction of the disordered pyrrolidine ring exhibits an envelope conformation while the minor component is essentially planar [maximum deviation = 0.037 (12) A]. The other pyrrolidine ring also adopts an envelope conformation. The dihedral angle between the mean planes of the two wings of the pyrrolidine ring is 30.6 (2)°. Both the major and minor components of the acenaphthylenone unit are essentially planar, the maximum deviations being 0.025 (10) and 0.047 (19) A, respectively; the dihedral angle between the mean planes of the two components is 1.72 (3)°. The crystal packing features C—H⋯O interactions.
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methyl 4 4 methoxy phen yl 1 2 3 3a 4 4a 5 12c octa hydro benzo f chromeno 3 4 b Pyrrolizine 4a carboxyl ate
Acta Crystallographica Section E-structure Reports Online, 2009Co-Authors: B Gunasekaran, Subban Kathiravan, R Raghunathan, V ManivannanAbstract:There are two molecules in the asymmetric unit of the title compound, C26H24ClNO3. The dihedral angles between the naphthalene ring system and the chlorophenyl substituent are 58.76 (9) and 51.59 (8)° in the two molecules. In the Pyrrolizine ring system, both the pyrrolidine rings adopt envelope conformations and the dihydropyran rings adopt half-chair conformations. In the Pyrrolizine ring system of one of the molecules, one of the C atoms is disordered over two positions with site occupancies of 0.69 (2) and 0.31 (2). The crystal packing is stabilized by weak intramolecular C—H⋯O interactions and the crystal packing is stabilized by weak C—H⋯π interactions.
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Methyl 4-(4-methoxyphenyl)-1,2,3,3a,4,4a,5,12c-octahydrobenzo[f]chromeno[3,4-b]Pyrrolizine-4a-carboxylate
Acta Crystallographica Section E-structure Reports Online, 2009Co-Authors: B Gunasekaran, Subban Kathiravan, R Raghunathan, V ManivannanAbstract:There are two molecules in the asymmetric unit of the title compound, C26H24ClNO3. The dihedral angles between the naphthalene ring system and the chlorophenyl substituent are 58.76 (9) and 51.59 (8)° in the two molecules. In the Pyrrolizine ring system, both the pyrrolidine rings adopt envelope conformations and the dihydropyran rings adopt half-chair conformations. In the Pyrrolizine ring system of one of the molecules, one of the C atoms is disordered over two positions with site occupancies of 0.69 (2) and 0.31 (2). The crystal packing is stabilized by weak intramolecular C—H⋯O interactions and the crystal packing is stabilized by weak C—H⋯π interactions.
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2′‐Benzoyl‐1′‐(4‐chlorophenyl)‐5′,6′,7′,7a′‐tetrahydrospiro[indan‐2,3′(2′H)‐1H‐Pyrrolizine]‐1,3‐dione
Acta Crystallographica Section E: Crystallographic Communications, 2005Co-Authors: S. Kalyanasundaram, S. Selvanayagam, Devadasan Velmurugan, Krishnan Ravikumar, Mahalingam Poornachandran, R RaghunathanAbstract:The title compound, C28H22ClNO3, has two crystallographically independent molecules in the asymmetric unit. The pyrrolidine ring (A) of the Pyrrolizine system adopts an envelope conformation in both molecules, whereas the other five-membered ring (B) adopts an envelope conformation in one molecule and a twist conformation in the other. The molecular packing is stabilized by intermolecular C—H⋯O, C—H⋯π and π–π interactions.
Pinggui Yi - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Dispiro[indole‐3,2′‐pyrrolidine‐3′,2″‐Pyrrolizine]‐1″,2(1H)‐diones via Azomethine Ylide 1,3‐Dipolar Cycloaddition
Journal of Heterocyclic Chemistry, 2013Co-Authors: Xiaofang Li, Rongqiong Yi, Zhikui Li, Xianyong Yu, Pinggui YiAbstract:The 1,3-dipolar cycloaddition of azomethine ylide generated in situ from isatin and sarcosine to 2-arylmethylidene-2,3-dihydro-1H-pyrrolizin-1-ones afforded novel 1′-methyl-4′-(aryl)-1″H-dispiro[indole-3,2′-pyrrolidine-3′,2″-Pyrrolizine]-1″,2(1H)-diones in good yields. The structures of all the products were characterized thoroughly by NMR, infrared spectroscopy, mass spectrum, and elemental analysis.
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synthesis of dispiro indole 3 2 pyrrolidine 3 2 Pyrrolizine 1 2 1h diones via azomethine ylide 1 3 dipolar cycloaddition
Journal of Heterocyclic Chemistry, 2013Co-Authors: Xiaofang Li, Rongqiong Yi, Zhikui Li, Xianyong Yu, Pinggui YiAbstract:The 1,3-dipolar cycloaddition of azomethine ylide generated in situ from isatin and sarcosine to 2-arylmethylidene-2,3-dihydro-1H-pyrrolizin-1-ones afforded novel 1′-methyl-4′-(aryl)-1″H-dispiro[indole-3,2′-pyrrolidine-3′,2″-Pyrrolizine]-1″,2(1H)-diones in good yields. The structures of all the products were characterized thoroughly by NMR, infrared spectroscopy, mass spectrum, and elemental analysis.
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synthesis of novel spiro pyrrolidine and Pyrrolizine derivatives by 1 3 dipolar cycloaddition
ChemInform, 2010Co-Authors: Xiaofang Li, Xianyong Yu, Aiting Zheng, Pinggui YiAbstract:Azomethine ylides, derived from isatin and sarcosine or proline, react with substrates of type (I)/(V) to give the novel dispiroheterocycles regio- and stereoselectively.
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synthesis of novel spiro pyrrolidine and Pyrrolizine derivatives by 1 3 dipolar cycloaddition
Chinese Journal of Chemistry, 2010Co-Authors: Xiaofang Li, Xianyong Yu, Aiting Zheng, Pinggui YiAbstract:The 1,3-dipolar cycloaddition of azomethine ylides derived from isatin and amino acids viz. sarcosine and proline to 2-arylmethylidene-5,6-dihydroimidazo[2,1-b]thiazol-3(2H)-ones afforded novel spiro pyrrolidines and pyrrolizidines regio- and stereoselectively in moderate yields. The products were characterized thoroughly by IR, MS, NMR together with elementary analysis.
Xiaofang Li - One of the best experts on this subject based on the ideXlab platform.
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synthesis of novel dispiro acenaphthylene pyrrolidine Pyrrolizine derivatives via a 1 3 dipolar cycloaddition of azomethine ylide
ChemInform, 2014Co-Authors: Xiaofang Li, Zhikui Li, Liyun Du, Rongjin ZengAbstract:generated in situ from acenaphthenequinone (IV) and sarcosine with 2-arylidenepyrrolizinone derivatives (III)
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Synthesis of Dispiro[indole‐3,2′‐pyrrolidine‐3′,2″‐Pyrrolizine]‐1″,2(1H)‐diones via Azomethine Ylide 1,3‐Dipolar Cycloaddition
Journal of Heterocyclic Chemistry, 2013Co-Authors: Xiaofang Li, Rongqiong Yi, Zhikui Li, Xianyong Yu, Pinggui YiAbstract:The 1,3-dipolar cycloaddition of azomethine ylide generated in situ from isatin and sarcosine to 2-arylmethylidene-2,3-dihydro-1H-pyrrolizin-1-ones afforded novel 1′-methyl-4′-(aryl)-1″H-dispiro[indole-3,2′-pyrrolidine-3′,2″-Pyrrolizine]-1″,2(1H)-diones in good yields. The structures of all the products were characterized thoroughly by NMR, infrared spectroscopy, mass spectrum, and elemental analysis.
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synthesis of dispiro indole 3 2 pyrrolidine 3 2 Pyrrolizine 1 2 1h diones via azomethine ylide 1 3 dipolar cycloaddition
Journal of Heterocyclic Chemistry, 2013Co-Authors: Xiaofang Li, Rongqiong Yi, Zhikui Li, Xianyong Yu, Pinggui YiAbstract:The 1,3-dipolar cycloaddition of azomethine ylide generated in situ from isatin and sarcosine to 2-arylmethylidene-2,3-dihydro-1H-pyrrolizin-1-ones afforded novel 1′-methyl-4′-(aryl)-1″H-dispiro[indole-3,2′-pyrrolidine-3′,2″-Pyrrolizine]-1″,2(1H)-diones in good yields. The structures of all the products were characterized thoroughly by NMR, infrared spectroscopy, mass spectrum, and elemental analysis.
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synthesis of novel spiro pyrrolidine and Pyrrolizine derivatives by 1 3 dipolar cycloaddition
ChemInform, 2010Co-Authors: Xiaofang Li, Xianyong Yu, Aiting Zheng, Pinggui YiAbstract:Azomethine ylides, derived from isatin and sarcosine or proline, react with substrates of type (I)/(V) to give the novel dispiroheterocycles regio- and stereoselectively.
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synthesis of novel spiro pyrrolidine and Pyrrolizine derivatives by 1 3 dipolar cycloaddition
Chinese Journal of Chemistry, 2010Co-Authors: Xiaofang Li, Xianyong Yu, Aiting Zheng, Pinggui YiAbstract:The 1,3-dipolar cycloaddition of azomethine ylides derived from isatin and amino acids viz. sarcosine and proline to 2-arylmethylidene-5,6-dihydroimidazo[2,1-b]thiazol-3(2H)-ones afforded novel spiro pyrrolidines and pyrrolizidines regio- and stereoselectively in moderate yields. The products were characterized thoroughly by IR, MS, NMR together with elementary analysis.
Eberhard Breitmaier - One of the best experts on this subject based on the ideXlab platform.
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2 3 dihydro 1h Pyrrolizine aus prolin und 3 alkoxyacroleinen
European Journal of Organic Chemistry, 1990Co-Authors: Gul Hassan Walizei, Eberhard BreitmaierAbstract:2,3-Dihydro-1H-Pyrrolizines from Proline and 3-Alkoxyacroleins 6-Alkyl-2,3-dihydro-1H-Pyrrolizines 5 have been obtained in moderate yields in a one-pot synthesis from substituted 3-alkoxyacroleins 2 and proline methyl ester (1) in the presence of sodium methoxide as base.
Oleg V Shishkin - One of the best experts on this subject based on the ideXlab platform.
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synthesis of masked vicinalamino aldehydes of Pyrrolizine and pyrrolo 1 2 c thiazole series
Synthesis, 2009Co-Authors: Anton V Tverdokhlebov, Alexander V Denisenko, Andrey A Tolmachev, Yulian M Volovenko, Svetlana V Shishkina, Oleg V ShishkinAbstract:Acylation of (1,3-dihydro-1,3-dimethyl-2 H-benzimidazol-2-ylidene)acetonitrilewith mixed anhydrides of N-Boc proline and4-thiazolidinecarboxylic acid was found to proceed at the exocycliccarbon atom yielding the corresponding C-acylderivatives. Removal of the protecting group with equimolar amountof hydrochloric acid effected simultaneous cyclization affording2-(3-amino-5,6,7,7a-tetrahydro-1-oxo-1 H-pyrrolizin-2-yl)-and 2-(5-amino-7,7a-dihydro-7-oxo-1 H,3 H-pyrrolo[1,2- C]thiazol-6-yl)-1,3-dimeth-ylbenzimidazoliumchlorides. Reduction of the prepared salts with sodium borohydrideresulted in 3-amino-2-(2,3-dihydro-1,3-di-methyl-1 H-benzimidazol-2-yl)-5,6,7,7a-tetrahydro-1 H-pyrrolizin-1-one and 5-amino-6-(2,3-dihydro-1,3-dimethyl-1 H-benzimidazol-2-yl)-1,7a-dihydro-3 H,7 H-pyrrolo[1,2- C]thiazol-7-one, respectively. Thesecompounds were shown to be masked aldehydes. Their reactions withphenylhydrazine and hydroxylamine yielded corresponding hydrazonesand oximes, whereas condensation with malononitrile furnished 2-amino-5a,6,7,8-tetrahydro-5-oxo-5 H-pyrido[3,2- B]Pyrrolizine-3-carbonitrileand 2-amino-5a,6-dihydro-5 H,8 H-thiazolo[3′,4′:1,5]pyrrolo[2,3- B]pyridine-3-carbonitrile.
