Preparation of 4‑Allenyloxazolines from (<i>Z</i>)‑2-En-4-yn-1-ol via Propargyl/Allenyl Isomerization

A novel method for the preparation of 4-allenyl-oxazolines <b>2</b> is described via the reaction of 2-en-4-yn-1-ols <b>1</b> with trichloroacetonitrile in the presence of DBU. Reaction proceeds through the nucleophilic attack of OH functionality in <b>1</b> to CCl₃CN followed by cyclization, propargyl/allene isomerization, and protonation. In this investigation, it is noticed that propargyl/allene isomerization is sensitive to the substituents.