The Buchner — Curtius — Schlotterbeck reaction — the reaction of the interaction of aldehydes and ketones with diazocompounds to form carbonyl compounds and substituted oxiranes:
Reaction Description
The reaction is carried out at room or lower temperature in diethyl ether . The catalysts are water , alcohols , lithium chloride . Of the diazo compounds, diazomethane , diazoacetic ether and ω-diazocrotonic acid ethyl ester are used. In a number of syntheses, the diazocompound is formed during the reaction from nitrosoalkylurethanes in the presence of bases in a methanol solution.
The direction of the Buchner-Curtius-Schlotterbeck reaction is determined by the structure of the initial carbonyl compound, however, all three products are most often formed during the reaction. With the introduction of electron-withdrawing substituents in the α-position to the carbonyl group of the starting compound, the reaction proceeds at a faster rate with the predominant formation of oxiranes . Electron-donating substituents in the α-position lead to an increase in the yield of carbonyl compounds. Ketones are less reactive than aldehydes, and the conversion to oxiranes is higher.
The interaction of alicyclic ketones with diazomethane leads to an extension of the cycle:
Reactions of dicarbonyl compounds lead to cyclic diesters:
α, β-unsaturated oxo compounds attach diazomethane in a double bond , with the formation of substituted 1-pyrazolines:
The by-products of the Buchner – Curtius – Schlotterbeck reaction are a consequence of the polymerization of diazocompounds and their interaction with the resulting carbonyl compounds.
Discovery History
The reaction was discovered in 1885 by German chemists E. Buchner and T. Curtius . Subsequently, the reaction was investigated by the German chemist F. Schlotterberg .
Literature
- Knunyants I. L. et al. Chemical Encyclopedia. - M .: Soviet Encyclopedia, 1988.- T. 1 (A - Darzan). - 623 p. - 100,000 copies.