A gener, sl and facile method to the highly reactive allene oxides has been developed. 1-tert- Butylallene oxide is isolated and characterized. 1-Alkyl-, 3-alkyl-, and 3-aryl-substituted allene oxides, when similarly generated, suffer regiospecific nucleophilic epoxide opening to give substituted ketones. On the other hand, 1-aryl-and 1, l-dialkylsubstituted allene oxides give products characteristic of cyclopropanones. These allene oxides, once ...