Download PDF
Synlett 1989; 1989(1): 15-18
DOI: 10.1055/s-1989-34701
letter
© Georg Thieme Verlag, Rüdigerstr. 14, 70469 Stuttgart, Germany. All rights reserved. This journal, including all individual contributions and illustrations published therein, is legally protected by copyright for the duration of the copyright period. Any use, exploitation or commercialization outside the narrow limits set by copyright legislation, without the publisher's consent, is illegal and liable to criminal prosecution. This applies in particular to photostat reproduction, copying, cyclostyling, mimeographing or duplication of any kind, translating, preparation of microfilms, and electronic data processing and storage.

η5-Cyclopentadienylcobalt-Mediated Inter- and Intramolecular [2+2+2] Cycloadditions of Alkynes to Aldehydes and Ketones: A Novel Synthesis of Fused 2H-Pyrans

Daniel F. Harvey* , Barry M. Johnson, Christopher S. Ung, K. Peter C. Vollhardt
  • *Department of Chemistry, University of California at Berkeley, and the Materials and Chemical Sciences Division, Lawrence Berkeley Laboratory, Berkeley, California 94720, USA
Further Information

Publication History

Publication Date:
26 February 2002 (online)

  PDF Download  Permissions and Reprints All articles of this category

η5-Cyclopentadienylcobalt complexes induce the cocyclization of alkynes with aldehydes and ketones to furnish mainly complexed bi- and tricyclic 2H-pyrans (7 examples) and/or their α, β, γ, δ-unsaturated carbonyl isomers (7 examples). The latter are derived formally from the former by electrocyclic ring-opening, in three cases possibly preceded by [1,5] hydrogen shifts.