- Unusual mechanism of hydrolysis of the tosyl cyanide-cyclopentadiene adduct to the lactam 2-azabicyclo[2.2.1]hept-5-en-3-one
-
Hydrolysis of the cycloaddition product derived from tosyl cyanide and cyclopentadiene was investigated using 18O label incorporation experiments; thus, sulfonyl imine 2 was transformed into 18O labelled lactam 3 with 18O labelled acetic acid, which is consistent with the intervention of intermediate 6 during the hydrolysis.
- Morgan, Paul E.,McCague, Ray,Whiting, Andrew
-
-
Read Online
- Hetero Diels-Alder reaction of benzenesulfonyl cyanide with cyclopentadiene using chiral Lewis acids
-
Asymmetric induction was observed in the hetero Diels-Alder reaction of benzenesulfonyl cyanide with cyclopentadiene using chiral Lewis acids. This is the first instance of asymmetric Diels-Alder reaction involving a sulfonyl group in the presence of a chiral Lewis acid.
- Katagiri, Nobuya,Makino, Masashi,Tamura, Takahiro,Kaneko, Chikara
-
-
Read Online
- Carbovir-related compounds and phosphonate analogues
-
Detailed syntheses of carbovir-related cis-[2-(9H-Purin-9-yl)-3- cyclopentene]-1-methanols and phosphonates of selected analogues are presented. Our interest in this chemistry stems from antiviral activity shown by closely related compounds. Access to the key β-lactam was achieved by the reaction of monocyclopentadiene with chlorosulfonyl isocyanate at -78°C rather than at the reported1 ambient temperature, where only the less ring-strained and more stable γ-lactam is formed. Copyright Taylor & Francis Group, LLC.
- Pham, Phuong-T.,Vince, Robert
-
-
Read Online
- Preparation method of aza-bicyclic [2, 2, 1] hepta-5-alkene-3-ketone
-
The invention provides a preparation method of aza-bicyclic [2, 2, 1] hepta-5-alkene-3-ketone. The preparation method includes the steps: S1) performing hybrid reaction on 1, 3-cyclopentadiene and cyanide under the condition of presence of crosslinked polystyrene sulfinic acid sodium to obtain a bicyclic compound; S2) hydrolyzing the bicyclic compound to obtain the aza-bicyclic [2, 2, 1] hepta-5-alkene-3-ketone. Compared with the prior art, the crosslinked polystyrene sulfinic acid sodium serves as a polymer-immobilized catalyst and can be recycled, the reaction post-treatment operation process is simplified, only simple filtration is needed, reaction yield is improved, cost is reduced, and environmental pollution is decreased.
- -
-
Paragraph 0036-0043
(2018/05/01)
-
- Substituted cyclopentane and cyclopentene compounds useful as neuraminidase inhibitors
-
Compounds I-III wherein U is CH, O, or S; Z is mono- or di-substituted carbon; R is (CH2)nCO2H, (CH2)nSO3H, (CH2)nPO3H2, (CH2)nNO2, CH(SCH3)3, esters; R1 is H, hydroxyalkyl, aminoalkyl, alkoxyalkyl; RR1 is O; n is 0-4; R2, R3 is H, hydroxyalkyl, aminoalkyl, alkoxyalkyl, haloalkyl; R4 is (CH2)nOH, (CH2)nNH2, substituted alkyl were prepd. as neuraminidase inhibitors. Thus, (1R,3R,4R,1′S)-(?)-(1′-acetylamino-2 ′-ethyl)butyl-4-(aminoimino)methylaminocyclopentan-1-carboxylic acid was prepd. and tested in vitro as neuraminidase inhibitor (IC501μM).
- -
-
-
- Novel 1,2-disubstituted carbocyclic nucleoside analogues of purine with a cyclopentene ring
-
A total and versatile synthesis of a new series of carbocyclic nucleoside analogues which are derivatives of purine with a 1,2-disubstituted cyclopentene ring (I) is described. The 6-chloropurine derivatives 3 and 9 were prepared by construction of the heterocyclic base about the primary amino group of the (±)-cis-2-amino-3-cyclopentenylmethanol (1), which was synthesized in good yield from cyclopentadiene in four steps. The substitution of a chlorine atom in the compounds 3 and 9 by an amino group (compounds 4 and 10) and by a hydroxyl group (compounds 5 and 11) was carried out with NH4OH or with NaOH, respectively.
- Besada,Gonzalez-Moa,Teran,Santana,Uriarte
-
p. 2445 - 2449
(2007/10/03)
-
- Process for producing 2-azabicyclo[2.2.1]hept-5-en-3-one
-
2-Azabicyclo[2.2.1]hept-5-en-3-one is prepared by a process comprising: continuously mixing a substituted sulfonyl cyanide represented by formula (I): R—SO2CN??(I), wherein R represents an alkyl group or a phenyl group or a substituted phenyl group, with cyclopentadiene; and then continuously adding the resultant reaction solution to water or to a mixed solvent comprising water and a hydrocarbon solvent under the condition that the pH of the present reaction mixture ranges from 4 to 7.
- -
-
-
- Process for producing and method of crystallizing 2-azabicyclo[2.2.1]hept-5-en-3-one
-
A process for producing 2-azabicyclo[2.2.1]hept-5-en-3-one is provided by reacting a sulfonyl cyanide represented by the general formula R-SO2CN (in which R represents an alkyl group or a phenyl group which may have a substituent), in the presence of water and in a hydrocarbon solvent at a pH of 4 to 7 inclusive. 2-Azabicyclo[2.2.1]hept-5-en-3-one can be produced in a high yield and a high purity in one step process, with a reduced amount of solvent used, safely and with good productivity. A method of crystallizing 2-azabicyclo[2.2.1]hept-5-en-3-one is also provided, which includes dissolving 2-azabicyclo[2.2.1]hept-5-en-3-one into an organic solvent mainly including at least one of diisopropyl ether and methyl tertiary butyl ether, cooling the solution to deposit crystals of 2-azabicyclo[2.2.1]hept-5-en-3-one. Finely divided particulate crystals of 2-azabicyclo[2.2.1]hept-5-en-3-one excellent in fluidity and handleability can be obtained with a simple procedure and in a high recovery rate.
- -
-
-
- π-Allylpalladium formation from allylic amines via N,N-ditosylimides and N-tosylamides: Efficient synthesis of the antiviral agent carbovir
-
Allylic amines can be easily converted into their N,N-ditosylimides or N-tosylamides which are sufficiently good leaving groups to afford π-allylpalladium complexes and, hence, with nucleophiles, new allylic systems with retention of configuration. The synthetic utility of this process has been demonstrated by an efficient synthesis of the antiviral agent (±)-carbovir (1) from cyclopentadiene in only seven steps and 13% overall yield.
- Jung,Rhee
-
p. 4719 - 4720
(2007/10/02)
-
- Process for the production of 2-azabicyclo [2.2.1] hept-5-en-3-one
-
2-Azabicyclo[2.2.1]hept-5-en-3-one is produced by Diels-Alder reaction of cyclopentadiene and methanesulfonyl cyanide and then hydrolytic cleavage of the methanesulfonyl group.
- -
-
-
- AN APPROACH TO THE ENANTIOSELECTIVE SYNTHESIS OF 2-AZABICYCLOHEPT-5-EN-3-ONE(1)
-
2-Azabicyclohept-5-en-3-one (1) was obtained with a 13percent enantiomeric excess by hydrolysis of the adduct formed by Diels-Alder addition of cyclopentadiene to the new chiral dienophile (+)-10-camphorsulphonyl cyanide (6) which was prepared in three steps from (+)-10-camphorsulphonic acid (3) in 44percent overall yield.
- Caamano, Olga,Eirin, Ana,Fernandez, Franco,Gomez, Generosa,Uriarte, Eugenio
-
p. 2839 - 2842
(2007/10/02)
-
- BIOHYDROXYLATION D'UN AZA-2 BICYCLO HEPTANE
-
Biohydroxylation with Beauveria sulfurescens of the 5-exo position of the 2-aza bicycloheptane ring system gives rise to a precursor of carbocyclic 2'-deoxy nucleosides.
- Archelas, Alain,Morin, Christophe
-
p. 1277 - 1278
(2007/10/02)
-
- Nitrenium and Carbenium Ions in Rearrangements of 2-Azabicyclic Systems
-
An ionic mechanism proceeding in intimate ion pairs is suggested for the rearrangement of N-sulfonyloxy derivatives of 2-azabicycloheptane and -hept-5-ene (e. g. 9, 11 -> 10, 12). 1.Experiments with 18O labelled educts show partial scrambling dependend both on structure of educt and solvent. 2.In methanol the intermediate carbenium ions (19, 23) react to give methoxy compounds. 3.MINDO/3-calculations are in agreement with the experiments: a) In the saturated systems the nitrenium ion 20 is a stable intermediate. b) The optimized geometries of the rearranged carbenium ions (21, 23) are consistent with the products obtained in methanol.
- Heesing, Albert,Herdering, Wilhelm
-
p. 1081 - 1096
(2007/10/02)
-
