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 ...