An Efficient Three??Step Synthesis of Cyclopenta [b] pyrans via 2??Donor??Substituted Fischer Ethenylcarbenechromium Complexes

…, M Noltemeyer, T Belgardt, B Knieriem

Index: De Meijere, Armin; Schirmer, Heiko; Stein, Frank; Funke, Frank; Duetsch, Michael; Wu, Yao-Ting; Noltemeyer, Mathias; Belgardt, Thomas; Knieriem, Burkhard Chemistry - A European Journal, 2005 , vol. 11, # 14 p. 4132 - 4148

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Citation Number: 11

Abstract

Abstract A wide range of cyclopenta [b] pyrans 4 has been synthesized in a one-pot reaction by treatment of different 2-donorsubstituted ethenylcarbenechromium complexes 2 with alkynes in THF in moderate to excellent yields (41–90% for 14 out of 25 examples). The starting materials 2 are readily available in good to excellent yields (76–99% for 25 out of 36 examples) by Michael addition of amines, alcohols and thiols, respectively, to the ...