P-Allenic amides

Isomerization reactions of 2-ynoic acids [59] and P-allenic amides [60] also provide suitable methodologies for the preparation of conjugated amides. The former compounds are isomerized by catalysis with ruthenium or iridium complexes and allow the synthesis of pellitorine (1), Achillea amide (4) and trichonine (13) (Scheme 15). 

The reaction of propargyl alcohols with amide acetals gives P-allenic amides, which can be isomerized to (2 ,4 )- [32] or (2 ,4Z)-dienamides [60] such as piperine (25) [32] and isochavicine (28) [60] (Scheme 16). 

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