Asymmetric nitrogen 78. Sterically hindered inversion of nitrogen atoms in cyclic hydrazines: N,N'-dialkyl-1,3,4-oxadiazolidines; 1,3,4-thiadiazolidine; and 4,5-benzo-1,2,3,6-tetrahydropyridazine

Article abstract of DOI:10.1007/BF02495930

N,N'-Diisopropyl-substituted 1,3,4-oxadiazolidine 3c, 1,3,4-thiadiazolidine 6, 4,5-benzo-1,2,3,6-tetrahydropyridazine 8, and new 3,4-dialkyl-1,3,4-oxadiazolines 9-14 were synthesized and studied.The configurational stability of the N atoms does not change on going from compounds 3c to its S-analog 6 and decreases in the case of pyridazine 8. 3,4-Di-tert-alkyl-1,3,4-oxadiazolidines 3d and 11-14 were found to be promising objects for optical resolution. - Keywords: N,N'-dialkyl-substituted 1,3,4-oxadiazolidines; 1,3,4-thiadiazolidine; 4,5-benzo-1,2,3,6-tetrahydropyridazine; nitrogen inversion; 1H, 13C NMR.