Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Electrocyclizations diene-conjugated ylides

Extensive work has been carried out on the 1,7-electrocyclization of diene-conjugated nitrile ylides (324) leading to fused heterocyclic systems containing the azepine ring (325). Reactions of this type for all 1,3-dipoles have been reviewed (197,198). [Pg.521]

Flash vacuum pyrolysis of oxiranes 156, accessible by a two-step procedure, results in carbonyl ylides 157, conjugated with a diene system formed by benzene and heterocyclic substituents R. They further undergo 1,7-electrocyclization and subsequent 1,5-sigma tropic hydrogen shift to give oxepines 158 and 159 (Scheme 31 (1997JCS(P1)3025, 1996JCS(P1)515)). [Pg.26]

See other pages where Electrocyclizations diene-conjugated ylides is mentioned: [Pg.535]    [Pg.535]    [Pg.72]    [Pg.535]    [Pg.99]   
See also in sourсe #XX -- [ Pg.520 , Pg.521 , Pg.522 , Pg.523 ]

See also in sourсe #XX -- [ Pg.520 , Pg.521 , Pg.522 , Pg.523 ]



SEARCH



1,3-Diene, conjugated

Conjugate 1,3 dienes

Conjugation Dienes, conjugated)

Dienes conjugated

© 2024 chempedia.info