نتایج جستجو برای: bicyclo

تعداد نتایج: 1233  

Journal: :journal of sciences islamic republic of iran 0

the acetone sensitized photolysis of the title compound gave 2-(2- oxopropy1)-9,9- dimethyl bicyclo [3.3.l]nona-3-one. a bridgehead cyclopropane intermediate was then suggested for the formation of the photoproduct

Journal: :Organic & biomolecular chemistry 2006
Santhosh Kumar Chittimalla Hui-Yi Shiao Chun-Chen Liao

A novel and convenient approach, the domino retro Diels-Alder/Diels-Alder reaction sequence for highly stereo- and regioselective synthesis of various bicyclo[2.2.2]octenone and bicyclo[2.2.2]octadienone derivatives is presented. Thus, the masked o-benzoquinones (MOBs) 2a-e generated by the pyrolysis of the respective dimers 3a-e participated in this novel synthetic strategy with a variety of o...

Journal: :international journal of bio-inorganic hybrid nanomaterials 0

two new samples of poly(amide-imide)/nanocomposites containing bicyclo segment and dibenzalaceton moiety in the main chain were synthesized by a solution intercalation technique. poly(amide-imide) (pai) 8 as a source of polymer matrix was synthesized by the direct polycondensation reaction of n,n´-bis(4-carboxyphenyl)bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic diimide 3 with 2,6-bis(4-amino...

2017
Sergey N Britvin Andrey M Rumyantsev

7-Aza-bicyclo-[2.2.1]heptane (7-aza-norbornane) is a bridged heterocyclic nucleus found in epibatidine, the alkaloid isolated from the skin of the tropical poison frog Epipedobates tricolor. Since epibatidine is known as one of the most potent acetyl-choline nicotinic receptor agonists, a plethora of literature has been devoted to this alkaloid. However, there are no structural data on the unsu...

2008
Amol M. Kendhale Rajesh G. Gonnade Gangadhar J. Sanjayan

In the molecule of the title compound, C(18)H(32)N(2)O(4), the central bicyclo-[3.3.0]octane (octa-hydro-penta-lene) has a rigid ring junction. Both rings of the bicyclo-[3.3.0]octane unit adopt an envelope conformation, and the flexible tert-butyl-carbamoyl side chains each have an extended conformation. Such a constrained bicyclo-[3.3.0]octane aliphatic template is of inter-est with respect t...

2011
Boubacar Sow Gabriel Bellavance Francis Barabé Louis Barriault

The rapid synthesis of bicyclo[m.n.1]alkanone cores possessing quaternary carbon centers adjacent to a bridged ketone represents a significant synthetic challenge. This type of architectural feature is embedded in various complex biologically active compounds such as hyperforin and garsubellin A. Herein, we report a highly diastereoselective one-pot Diels-Alder reaction/Au(I)-catalyzed carbocyc...

Journal: :Zeitschrift fur Naturforschung. C, Journal of biosciences 2012
Anna Pachuta-Stec Urszula Kosikowska Anna Chodkowska Monika Pitucha Anna Malm Ewa Jagiełło-Wójtowicz

N-Substituted amides of endo-3-(3-methylthio-1,2,4-triazol-5-yl)bicyclo[2.2.1]hept-5-ene-2-carboxylic acid and 1-(5-methylthio-1,2,4-triazol-3-yl)cyclohexane-2-carboxylic acid were prepared by the condensation reaction of endo-S-methyl-N1-(bicyclo[2.2.1]hept-5-ene-2,3-dicarbonyl)isothiosemicarbazide and S-methyl-N1-(cyclohexane-2,3-dicarbonyl)isothiosemicarbazide with primary amines. The synthe...

2017
Sergey N Britvin Andrey M Rumyantsev

The cage of 2,5-di-aza-bicyclo-[2.2.1]heptane is frequently employed in synthetic chemistry as a rigid bicyclic counterpart of the piperazine ring. The 2,5-di-azabicyclo-[2.2.1]heptane scaffold is incorporated into a variety of compounds having pharmacological and catalytic applications. The unsubstituted parent ring of the system, 2,5-di-aza-bicyclo-[2.2.1]heptane itself, has not been structur...

2004
Vijayakumar N. Sonar Sean Parkin Peter A. Crooks

Crystals of (Z )-2-(1-methyl-1H-indol-3-ylmethylene)-1-aza-bicyclo[2.2.2]octan-3-one (I) were obtained from a condensation reaction of 1-methyl-1H-indole-3-carboxaldehyde with 1-aza-bicyclo[2.2.2]octan-3-one and subsequent crystallization of the product from methanol. The isomeric (E)-2-(1-methyl-1H-indol-3-ylmethylene)-1-aza-bicyclo[2.2.2] octan-3-one hydrochloride (II) was obtained by treatin...

Journal: :The Journal of organic chemistry 2004
John E Baldwin Sarah S Gallagher Phyllis A Leber Anuradha S Raghavan Rajesh Shukla

The thermal conversion of cis-bicyclo[4.2.0]oct-7-ene to cis,cis-1,3-cyclooctadiene might involve a direct disrotatory ring opening, or it might possibly take place by way of cis,trans-1,3-cyclooctadiene. This cis,trans-diene might possibly form the more stable cis,cis isomer through a [1,5] hydrogen shift or a trans-to-cis isomerization about the trans double bond. Deuterium kinetic isotope ef...

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