Preparation of 4-Allenyloxazolines from ()-2-En-4-yn-1-ol via Propargyl/Allenyl Isomerization.

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