Lewis Acid Catalyzed Intramolecular Allylic Substitution of Bis(trichloroacetimidates): A Versatile Approach to Racemic Unsaturated Amino Acids

Lewis acid catalyzed cyclization of trichloroacetimidates derived from 1,4-butenediols and 1,5-butenediols was achieved to give 4-vinyl oxazolines and 4-vinyloxazines in good to excellent yields. The cyclization products were transformed to protected unsaturated α- and β-amino acids, thus demonstrating the novel approach to access these important classes of compounds