The Reactions of nitrile oxides with camphene under slow diffusion of DIPEA vapor lead to regio- and stereoselective formation of 5-spiro oxazolidines.

Abstract

1,3-Dipolar cycloaddition reactions of nitrile oxides to camphene were studied. Slow diffusion of DIPEA vapor into a solution containing N-hydroxyimidoyl halide as a precursor of 1,3-dipole was used to effectively generate unstable nitrile oxides. For the first time, the regio- and stereoselectivity of the nitrile oxides cycloaddition to camphene was established: 1,3-dipoles add from the exo side of C═C double bond with the formation of 5-spiro oxazolidines. Synthesized spiroisoxazolidines were tested for antiviral activity against the influenza A virus of H1N1 subtype; compounds with a reasonable inhibitory effect and selectivity were revealed.