EFFECTS OF ACID STRENGTH ON SCHMIDT REACTIONS OF ALKYL CYCLOPROPYL KETONES AND ALKYL PHENYL KETONES

Alkyl cyclopropyl ketones undergo acid-catalyzed reactions with hydrazoic acid (Schmidt reactions) to give isomeric amides by competitive migration of alkyl and cyclopropyl groups. The ratios of isomeric amides formed from these ketones are markedly influenced by the acidity of the reaction medium. Evidence is presented that these Schmidt reactions occur via (1) decomposition of -hydroxyhydrazidium ion intermediates in media of low acidities and (2) collapse of syn- and anti-iminodiazonium ions in strong acid environments. Schmidt reactions of alkyl phenyl ketones and cyclopropyl phenyl ketones also give amide pairs. The isomer ratios from these systems are not affected by the catalyst acidity, and it is presumed that these processes involve syn- and anti -iminodiazonium ions exclusively. © 1979, American Chemical Society. All rights reserved.