Reduction by Dissolving Metals

Abstract

The reduction by sodium and ethanol, with or without liquid ammonia as solvent, of various amidines followed by acid hydrolysis, leads in many cases to a good yield of the corresponding aldehyde. Further reduction in liquid ammonia of several Z-arylimidazolines or imidazolidines followed by acid hydrolysis leads to the 2,5-dihydrobenzaldehyde derivative.The reduction of some acid amides by sodium and proton sources in liquid ammonia has been examined. Under the right conditions this process is of preparative value for aldehydes.

Reductive Cleavage of Acylproline Peptide Bonds*

“…The effect of treatment with sodium in liquid ammonia on the amino acid compositions of three large polypeptides was examined in order to measure the extents of cleavage of the acylproline peptide bonds in each polypeptide and to detect side reactions that would result in the chemical modification of amino acid residues. Since the reductive cleavage of acylproline peptide bonds results in reduction of the acyl group to either an alcohol or aldehyde or both (Ressler and Kashelikar, 1966;Birch et al, 1955), one would expect that amino acid residues adjacent and N terminal to proline residues would be destroyed in proportion to the extent of reductive cleavage of the acylproline peptide bonds. For example, the extent of cleavage of acetylglycylproline calculated from glycine destruction agreed very well with the extent of cleavage calculated from proline release (Table III).…”

Stereochemistry of Reduction of Ketones by Complex Metal Hydrides

“…The product, previously reported as A4-cholestene (13), was shown to be a mixture of cholestene with about 10% cholestane. Hydrogeilolysis has been observed in the reduction of other compounds by this reagent (14,15). Cholest-5-en-3-one gave a mixture which contained Can.…”

CH‐Acidität in α‐Stellung zum N‐Atom in N,N‐dialkylamiden mit sterisch geschützter Carbonylgruppe zur nucleophilen minoalkylierung

“…6-12). Im Gegensatz zu anderen Amiden, die unter den Bedingungen der oder mit Natriumamalgam in Methanol [16] unter Freisetzung des Amins gespalten werden, wird 25 aus der Umsetzung rnit Lithium oder Natrium in flussigem Ammoniak unverandert zuruckerhalten (Nr. 6).…”