Photolysis and Thermolysis of N-Alkoxycarbonyl-α-diazoamide Acetals

In the photoysis and thermolysis of 1-phenyl-2,2-dimethoxy-2-(N-alkoxycarbonylamino)-diazoethanes the presence of the N-alkoxyearbonylamino substituent is of fundamental importance. In both cases the carbene intermediate, through intramolecular addition to carbonyl oxygen, gives, as main products, oxazole derivatives. In the thermolysis, especially at relatively low temperature (160°), the diazoamide acetals in part cyclize to form triazole derivatives.