Our recent studies concerning the ozonolysis of various azoles are rev
iewed in this paper. In spite of their remarkable stabilities under ac
idic, basic, oxidative and/or reductive conditions due to their aromat
icity, azoles are especially labile toward ozone. The reaction product
s and the mechanisms of the ozonolysis of pyrroles, oxazoles, and imid
azoles are summarized. Moreover, the ozonolysis of azoles is described
in view of its use in the protection-deprotection of functional group
s. In particular, the ozonolysis of pyrroles and oxazoles during pepti
de synthesis is illustrated.