Subscribe to RSS
DOI: 10.1055/s-2003-38063
Indium(I)-Mediated, Tandem Carbonyl Addition-Oxy-Cope Rearrangement of γ-Pentadienyl Anions to Cyclohexenones and Conjugated Aromatic Ketones
Publication History
Publication Date:
21 March 2003 (online)
![](https://www.thieme-connect.de/media/synthesis/200305/lookinside/thumbnails/10.1055-s-2003-38063-1.jpg)
Abstract
Treatment of 5-bromopenta-1,3-diene with indium metal in the presence of α,β-unsaturated ketones results in initial γ-pentadienylation to generate the hydroxy-1,4-diene. In the case of aromatic conjugated ketones or cyclohexenones the indium alkoxide undergoes spontaneous oxy-Cope rearrangement to afford the 1,4-addition product. The second double bond is required for this [3,3] sigmatropic rearrangement as allyl groups fail to under go this in situ rearrangement. This behavior is consistent with an indium(I) pentadiene species and appears to be the first example of an indium-mediated oxy-Cope rearrangement.
Key words
indium - oxy-Cope - [3,3] sigmatropic rearrangement - γ-pentadienyl - conjugate addition
-
1a
Woo S.Squires N.Fallis AG. Org. Lett. 1999, 1: 573 -
1b
Hirashita T.Inoue S.Yamamura H.Kawai M.Araki S. J. Organomet. Chem. 1997, 549: 305 - 2
Negishi E.-I. Organometallics in Organic Synthesis Vol. 1: Wiley; New York: 1980. p.30-59 - 3
Woo S.Legoupy S.Parra S.Fallis AG. Org. Lett. 1999, 1: 1013 - 4
Kwon O.Park SB.Schreiber SL. J. Am. Chem. Soc. 2002, 124: 13402 - 5
Melekhov A.Fallis AG. Tetrahedron Lett. 1999, 40: 7867 -
6a
Gerard F.Miginiac P. Bull. Soc. Chim. Fr. 1974, 1924 -
6b
Wilson SR.Mao DT.Jernberg KM.Ezmirly ST. Tetrahedron Lett. 1977, 2559 - 7
Evans DA.Nelson JV. J. Am. Chem. Soc. 1980, 102: 774 - 8
Hrovat DA.Beno BR.Lange H.Yoo H.-Y.Houk KN.Borden WT. J. Am. Chem. Soc. 1999, 121: 10529 - 9
Doering WE.Wang Y. J. Am. Chem. Soc. 1999, 121: 10112 - 11
Chan TH.Yang Y. J. Am. Chem. Soc. 1999, 121: 3228 - 12
Forgione P.Wilson PD.Yap GPA.Fallis AG. Synthesis 2000, 921 - 13
Haeffner F.Houk KN.Reddy R.Paquette LA. J. Am. Chem. Soc. 1999, 121: 11880
Reference
General Procedure: 5-Bromopenta-1,3-diene (7.21 mmol) and the ketone (1.81 mmol) were dissolved in DMF (1.3 mL) at 0 °C. Indium(powder) was added and the reaction was stirred at 21 °C for 4 h. The reaction was diluted with CH2Cl2 (5 mL) and Et2O (15 mL) and filtered through a silica pad and purified by flash chromatography.