KO(t)Bu-promoted three-component coupling of aldehydes and alkynes: highly efficient synthesis of 1-en-4-yn-3-ols and 2-en-4-yn-1-ols.

A KO(t)Bu-promoted three-component coupling reaction of aldehydes and alkynes without a transition-metal catalyst was developed in which the sequential addition/isomerization/addition processes take place in one pot. This reaction could be developed into a straightforward and effective method for rapid access to stereodefined (E)-1-en-4-yn-3-ol and (Z)-2-en-4-yn-1-ol compounds.