H. Pavez, A. Márquez, P. Navarrete
1987
Citations
0
Influential Citations
11
Citations
Journal
Tetrahedron
Abstract
Abstract Δ4-1,2,4-Oxadiazolin-3-carboxylic acids, 3a_3i, were obtained by 1,3-d i polar cycloaddition between Δ2-oxazolin-5-ones, 1 , and nitrosobenzene, 2. The reaction occurs regiospecifically at room temperature, the mesoionic form of 1 acting as the 1,3-dipole and the N=O group of 2 acting as the dipolarophile. Xylene or DMF are used as solvents. The thermally unstable aminoacids were converted into their methyl esters, 4a–41 , by treatment with diazomethane. The esters were characterized by their physical properties.