Lewis acid catalyzed intramolecular allylic substitution of bis(trichloroacetimidates): A versatile approach to racemic unsaturated amino acids

Article abstract of DOI:10.1002/ejoc.201100060

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. Lewis acid catalyzed cyclization of allylic bis(trichloroacetimidates) (n = 1, 2) provides 4-vinyloxazolines and 4-vinyloxazines. The products of cyclization weredemonstrated to be versatile intermediates for the synthesis of unsaturated α- and β-amino acids. Copyright