Abstract: A general synthesis of 1-azirines is described involving the photolysis of vinyl azides, which in turn can be readily obtained from the correspondiag olefins. The photolysis usually proceeds in high yield and can also be applied to the synthesis of fused azirines. Infrared and nmr spectral properties as well as reactions of 1-azirines are discussed. Photolysis of vinyl azides in methanol containing sodium methoxide leads to amino ketals ...