Stereochemistry and thermal stability of diazodiketones

Abstract

The thermal stability of diazodiketones strongly depends on the twisting of the molecular framework caused by steric interaction of substituents at the carbonyl groups. On going from planar cyclic 2-diazo-4, 4-dimethyltetralin-1,3-dione to sterically congested mesitoylpivaloyldiazomethane the rate of decomposition increases 100 times. On the other hand, bulky substituents also decrease the reactivity of 2-ketoketenes formed in the Wolff rearrangement of these diazocarbonyl compounds.