Fpjt. Rutjes et al., Selective azetidine and tetrahydropyridine formation via Pd-catalyzed cyclizations of allene-substituted amines and amino acids, ORG LETT, 1(5), 1999, pp. 717-720
[GRAPHICS]
By choosing the right substituents either highly functionalized unusual fou
r-membered ring amino acids or the isomeric pipecolic acid derivatives are
obtained in enantiomerically pure form. Starting material is a linear allen
e containing amino acid that has been resolved via biocatalysis.