scholarly journals Synthesis of the tricyclic core of manzamine A

2015 ◽  
Vol 13 (11) ◽  
pp. 3331-3340 ◽  
Author(s):  
Ravindra B. Pathak ◽  
Benjamin C. Dobson ◽  
Nandita Ghosh ◽  
Khalid A. Ageel ◽  
Madeha R. Alshawish ◽  
...  
Keyword(s):  
Ring System ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Manzamine A ◽  
Tricyclic Core ◽  
Manzamine Alkaloids

An approach to the ABC tricyclic ring system of the manzamine alkaloids has been achieved. A key step is the intramolecular dipolar cycloaddition of an azomethine ylide.

scholarly journals Synthesis of fused tricyclic amines unsubstituted at the ring-junction positions by a cascade condensation, cyclization, cycloaddition then decarbonylation strategy

2012 ◽  
Vol 8 ◽  
pp. 107-111 ◽  
Author(s):  
Iain Coldham ◽  
Adam J M Burrell ◽  
Hélène D S Guerrand ◽  
Luke Watson ◽  
Nathaniel G Martin ◽  
...  
Keyword(s):  
Ring System ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Reaction Sequence ◽  
Hydroxymethyl Group ◽  
The Core ◽  
Stereochemical Control ◽  
Ring Junction ◽  
Group A ◽  
Very High

Heating aldehydes that contain a protected hydroxymethyl group, a tethered alkyl chloride and a tethered alkenyl group at the α-position of the aldehyde with an amine sets up a cascade (tandem) reaction sequence involving condensation to an intermediate imine, then cyclization and formation of an intermediate azomethine ylide and then intramolecular dipolar cycloaddition. The fused tricyclic products are formed with complete or very high stereochemical control. The hydroxymethyl group was converted into an aldehyde – which could be removed to give the tricyclic amine products that are unsubstituted at the ring junction positions – or was converted into an alkene, which allowed the formation of the core ring system of the alkaloids scandine and meloscine.

Reactions of 4-Pyrones with Azomethine Ylides as a Chemo­selective Method for the Construction of Multisubstituted Pyrano[2,3-c]pyrrolidines

Synthesis ◽  
2021 ◽  
Author(s):  
Dmitrii L. Obydennov ◽  
Vyacheslav D. Steben’kov ◽  
Konstantin L. Obydennov ◽  
Sergey A. Usachev ◽  
Vladimir S. Moshkin ◽  
...  
Keyword(s):  
Double Bond ◽  
Ring Opening ◽  
Azomethine Ylides ◽  
Azomethine Ylide ◽  
Dipolar Cycloaddition ◽  
Computational Studies ◽  
Carbon Double Bond ◽  
Reactivity Indexes ◽  
Reaction Proceeds

Abstract4-Pyrones bearing electron-donating and electron-withdrawing groups react with nonstabilized azomethine ylides to form pyrano[2,3-c]pyrrolidines in moderate to good yields. The reaction proceeds chemoselectively as a 1,3-dipolar cycloaddition of the azomethine ylide at the carbon–carbon double bond of the pyrone activated by the electron-withdrawing substituent. The reactivity of 4-pyrones toward azomethine ylides was rationalized by computational studies with the use of reactivity indexes. The pyrano[2,3-c]pyrrolidine moiety could be modified, for example by a ring-opening transformation under the action of hydrazine to provide pyrazolyl-substituted pyrrolidines.

A concise enantioselective synthesis of the AB ring system of the manzamine alkaloids by ring-closing enyne metathesis

2001 ◽  
Vol 42 (18) ◽  
pp. 3235-3238 ◽  
Author(s):  
J.Stephen Clark ◽  
Robert J Townsend ◽  
Alexander J Blake ◽  
Simon J Teat ◽  
Amanda Johns
Keyword(s):  
Ring System ◽  
Enantioselective Synthesis ◽  
Enyne Metathesis ◽  
Manzamine Alkaloids ◽  
Ab Ring

ChemInform Abstract: 4,6-Dinitrobenzo[c]isothiazole: Synthesis and 1,3-Dipolar Cycloaddition to Azomethine Ylide.

ChemInform ◽  
2011 ◽  
Vol 42 (13) ◽  
pp. no-no
Author(s):  
Lidia S. Konstantinova ◽  
Maxim A. Bastrakov ◽  
Aleksei M. Starosotnikov ◽  
Ivan V. Glukhov ◽  
Kirill A. Lysov ◽  
...  
Keyword(s):  
Azomethine Ylide ◽  
Dipolar Cycloaddition
Sign in / Sign up

Export Citation Format

Share Document