Stereospecific non-decarboxylative 1,3-dipolar cycloaddition as a potential route to proline derivatives, part III1

Abstract

Boiling an equimolar mixture of salicylaldehyde 1a, DL-alanine 2a and dimethyl fumarate 3 in acidified methanol gives a mixture of three stereoisomers 4a-c. The effect of solvent and temperature on the diastereoselectivity is pronounced. Using fumaronitrile 13 as dipolarophile gives stereospecifically the fused tricyclic cycloadducts 16a-f. Boiling an equimolar mixture of salicylaldehyde 1a, DL-alanine 2a and dimethyl fumarate 3 in acidified methanol gives a mixture of three stereoisomers 4a-c. The effect of solvent and temperature on the diastereoselectivity is pronounced. Using fumaronitrile 13 as dipolarophile gives stereospecifically the fused tricyclic cycloadducts 16a-f.13.