1,4-Elimination/Brønsted acid catalyzed aza-Ferrier reaction sequence as an entry to β-amino-β,γ-unsaturated aldehydes

The 1,4-elimination reaction of (Z)-N-Boc-2-(4-methoxy-2-alkenyloxy)amines with Brønsted acids catalyzed aza-Ferrier reaction of the 1,4-eliminated product, thus obtained, afforded various β-amino-β,γ-unsaturated aldehydes. The scope and limitation of this sequential reaction are described.