Das Ketocarben-Oxiren-Gleichgewicht unter einem präparativen Aspekt≠

Abstract

The photochemical decomposition of α-diazoketone 1 in toluene gives rise to the formation of the well known keto carbene-oxirene equilibrium from which not only the product of the Wolff rearrangem ent can be derived but also the com pounds 5, 6 and 7 which are formed directly via the corresponding keto carbenes A and B respectively. Formation of the azulene 6 is unexpected in this context, it's structure could be revealed by X-ray analysis. The results may be regarded as an additional contribution to the mechanism of the Wolff rearrangement, but what is more, they could serve as a model for the feasibility of mechanistic oxirene chemistry in a more preparative aspect.