1,3-Dipolar cycloaddition of 1-substituted 3,3,3-trifluoropropenes to ethyl cyanocarboxylate <italic>N</italic>-oxide.

<graphic></graphic>3,3,3-Trifluoropropene derivatives containing a sulfonyl, sulfoximine, or sulfamide substituent at position 1 were used in 1,3-dipolar cycloaddition reaction with ethyl cyanocarboxylate <italic>N</italic>-oxide generated by thermal decomposition of ethyl oximinochloroacetate, resulting in the formation of isomeric 4(5)-substituted ethyl 5(4)-(trifluoromethyl)-4,5-dihydroisoxazole-3-carboxylates and ethyl 4-(trifluoromethyl) isoxazole-3-carboxylate. [ABSTRACT FROM AUTHOR]