Synthesis of new heterocycles through a cation-driven tandem ring-enlargement-annulation reaction.
[reaction: see text] The thionium ion, generated through a cyclopropylcarbinyl-cyclobutyl ring expansion, is, for the first time, intramolecularly intercepted by activated aromatic rings to generate new versatile 2a-methyl-8b-(phenylsulfanyl-1,2a,3,8b-tetrahydro-2H-cyclobuta[c]chromenes.
Dipartimento di Scienze Chimiche, Università degli studi di Cagliari, Cittadella Universitaria di Monserrato, S.S 554, Bivio per Sestu, I-09042 Monserrato (Cagliari), Italy. ppiras@unica.it
Angela M
AM
Bernard
Enzo
E
Cadoni
Angelo
A
Frongia
Pier P
PP
Piras
Francesco
F
Secci
D001578:Benzopyrans / Q000138:chemical synthesis; D001685:Biological Factors / Q000138:chemical synthesis; D002412:Cations / Q000737:chemistry; D003500:Cyclization; D003503:Cyclobutanes / Q000138:chemical synthesis; D006571:Heterocyclic Compounds / Q000138:chemical synthesis*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry
D001578:Benzopyrans; D001685:Biological Factors; D002412:Cations; D003503:Cyclobutanes; D006571:Heterocyclic Compounds; D000644:Quaternary Ammonium Compounds; C019539:precocene I; C059915:thionium