Pauson-Khandreactions are carried out with different substituted aromatic enynes, yielding tricyclic cyclopentenones related to natural products such as chromenes. Enynes are easily obtained in a two-step approximation from the corresponding salicylaldehydes. The reaction is promoted by dissolved TMANO (trimethylamine N-oxide) and/or 4 A molecular sieves. This new way of induction for the Pauson-Khand
Pauson-Khand reactions are carried out with different substituted aromatic enynes yielding tricyclic cyclopentenones related to natural products. Reaction is promoted by dissolved Me3NO. Isomerization of the double bond of the cyclopentenone is observed except for compound 2e, with a non terminal triple bond.