CYCLOADDITIONS OF KETENES WITH N-FLUORENYLIDENEALKYL AMINE AND N-FLUORENYLIDENEALKYL ARYLAMINE OXIDES - SYNTHESIS OF SPIROOXAZOLIDINONES AND SPIROISOXAZOLIDINONES

The cycloadditions of several IV-fluorenylidenearylamine and-alkylamine oxides (1 and 2) with cyclopentamethyleneketene, tert-butylcarbethoxyketene, and tert-butylcycanoketene were investigated. In general, the IV-aryl derivatives afforded spirooxazolidinones (3) while the N-alkyl derivatives gave spiroisoxazolidinones (4). 1H NMR and 13C NMR studies of 3 and 4 were carried out to substantiate their structures. A mechanistic scheme which accounts for all of the observed cycloaddition products is proposed. © 1979, American Chemical Society. All rights reserved. © 1979, American Chemical Society. All rights reserved.