Non-decarboxylative 1,3-dipolar cycloadditions of imines of α-amino acids as a route to proline derivatives.
摘要:
alpha-Amino acids react with aryl aldehydes in the presence of N-substituted maleimides to yield stereospecific cycloadducts (3a,b) with dimethyl fumarate to give isometric mixtures of (4a-i) and (5a-i). The relatively low yield in the case of dimethyl fumarate is presumably due to the steric interaction between the dipolarophile and the substituents at both ends of the dipole.