1,8-diazafluorenone (DFO) reacts with [alpha]-amino acids and their esters via imine formation to give decarboxylated azomethine ylides and ester substituted azomethine ylides respectively. In the presence of N-methylmaleimide these azomethine ylides undergo stereospecific cycloaddition via endo-transition states. Analogues of DFO give similar cycloadducts. In the absence of dipolarophiles the [alpha]-amino acids and DFO give a red fluorescent dye thus providing a sensitive method for detecting latent fingerprints on paper.