| Abstract: | Hydrolysis of secondary diazoketones CH3? CO? CN2? R (R ? Me, Et, isopropyl) by aqueous perchloric acid is characterized by rate-determining protonation demonstrated by solvent isotope effects kD2O/kH2O = 0,4–0,6 and by the intervention of general acid catalysis. The product determining step, yielding keto-alcohols and keto-olefines, is independent of added nucleophiles; this is interpreted as resulting from the intermediate formation of (more or less free) αhyphen;ketocarbonium is ions. The hydride shift observed wih III (R = isopropyl) supports this interpretation. The difference between hydrolysis of primary and of secondary diazoketones is discussed. |
