6-Hydroxy-2-ynamide

This kind of reactivity turned out to be particularly attractive when applied to suitably functionalized terminal alkynes. Oxidative monoaminocarbonylation of 4-yn-l-ols led to the formation of tetrahydrofuran derivatives through intramolecular conjugate addition of -OH group to the triple bond of the initially formed 6-hydroxy-2-ynamide intermediates (Scheme 38) [310]. 

Even more interesting was the reaction of a-substituted propynyl alcohols and amines. In this case, in fact, the initially formed 4-hydroxy-2-ynamides... 

Propargyl alcohol was first monoaminocarbonylated leading to 4-hydroxy-2-ynamide 111. This first stage is followed in situ by conjugate addition of dialkylamine to the triple bond of the ynamide to yield 112 which gives spontaneously an intramolecular lactonization to afford the furanone 113. Similarly, lactams have been prepared using propargyl amines [99]. 

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