Synthesis of Spirocyclic and Tricyclic Isoxazoline via 1,3-Dipolar Cycloaddition Reactions

Abstract

1,3-Dipolar cycloadditions of the bicyclic monoterpenes (S)-(-)-camphene (1), (R)-(+)-a-pinene (2), and (S)-(-)-b-pinene (3) with aryl and heteroaryl nitrile oxides afforded new spirocyclic and tricyclic isoxazoline derivatives 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 whose biological activities were evaluated in bioassay studies.