Ring contraction of dihydro-1,3-thiazines to pyrroles on cyclisation

Citation
Gm. Davies et al., Ring contraction of dihydro-1,3-thiazines to pyrroles on cyclisation, J CHEM S P1, (24), 1999, pp. 3565-3567
Citations number
6
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 1
ISSN journal
0300922X → ACNP
Issue
24
Year of publication
1999
Pages
3565 - 3567
Database
ISI
SICI code
0300-922X(1999):24<3565:RCODTP>2.0.ZU;2-B
Abstract
Dihydrothiazines such as 8 and 12, which are disubstituted at C-7, undergo an interesting cyclisation-ring contraction reaction with substituted acryl ic acids yielding the pyrroles 9 and 13 respectively. This contrasts with t he corresponding reaction of thiazines 2 which are monosubstituted at C-7 w hich undergo a simple cyclisation reaction. A mechanism is suggested for th e cyclisation-ring contraction process.