Beilstein J. Org. Chem.2019,15, 2036–2042, doi:10.3762/bjoc.15.200
synthesis of new pyrrolidinenitroxides from 5,5-dialkyl-1-pyrroline N-oxides via the introduction of a pent-4-enyl group to the nitrone carbon followed by an intramolecular 1,3-dipolar cycloaddition reaction and isoxazolidine ring opening. The kinetics of reduction of the new nitroxides with ascorbate were
studied and compared to those of previously published (1S,2R,3′S,4′S,5′S,2″R)-dispiro[(2-hydroxymethyl)cyclopentan-1,2′-(3′,4′-di-tert-butoxy)pyrrolidine-5′,1″-(2″-hydroxymethyl)cyclopentane]-1′-oxyl (1).
Keywords: aldonitrone; 1,3-dipolar cycloaddition; pyrrolidinenitroxides; 1-pyrroline-N-oxide
could expect that the removal of electron-withdrawing tert-butoxy groups at positions 3 and 4 of the pyrrolidine ring of 1 (Figure 1) should lead to a further decrease in the reduction rate of the nitroxide.
Here we describe the synthesis of C1-symmetric racemic 3,4-unsubstituted pyrrolidinenitroxides