Diastereoselective Synthesis of Novel Spiro-Isoxazolidines via [3 + 2] Cycloaddition

Abstract

In this protocol, synthesis of novel 2,5-diphenyl-3,3-spiropentamethylene-5H-2,3,3a,6a-tetrahydropyrrolo[3,4-d]isoxazole-4,6-diones through [3 + 2] cycloaddition of N-cyclohexylidene N-phenyl nitrones with cyclic dipolarophiles is described. 1,3-Dipolar cycloaddition of nitrones with substituted N-arylmaleimides gives exclusively endo-diastereoisomers of spiro-isoxazolidines and their stereochemistry was assigned using ¹H NMR and ¹H-¹H correlation spectroscopic studies.

GRAPHICAL ABSTRACT

Keywords:

• [3 + 2] Cycloaddition
• N-arylmaleimides
• N-cyclohexylidene n-phenyl nitrone
• spiro-isoxazolidines

ACKNOWLEDGMENTS

The authors are thankful to the University Grant Commission (UGC), New Delhi, for financial assistance and the Sophisticated Analytical Instrumentation Facility (SAIF), Panjab University, Chandigarh, for spectral analysis.

Notes

^a The products were characterized by spectral techniques like IR, ¹H NMR, ¹³CNMR, and mass.

^b Isolated yields after recrystallization.