Thermal rearrangement of α-diazo-β-diketones
Abstract
From the thermal Wolff rearrangement of diacyldiazomethanes, ArCO·CN2·COR, products arising from the migration of both Ar and R groups have been isolated. Relative migrational aptitudes are mesityl (98), 2,4,6-Br3C6H2-(8), Ph (3), and Me (2), suggesting that, while both steric and electronic effects are important, the steric factor is dominant when the two are in opposition. These results provide a novel route to a number of ketones. β-keto-esters, and N-(2-arylacetyl)sulphonamides.