- Synthesis of new heterocycles through a cation-driven tandem ring-enlargement-annulation reaction.
Synthesis of new heterocycles through a cation-driven tandem ring-enlargement-annulation reaction.
Organic letters (2002-07-19)
Angela M Bernard, Enzo Cadoni, Angelo Frongia, Pier P Piras, Francesco Secci
PMID12123377
ABSTRACT
[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.
MATERIALS