Locquin

BOUVEAULT - LOCQUIN Aminoacid synthesis Synthesis of aminoacids from mahnale esters by nrtrosation... 

Of greater importance for the preparation of these substances is the reaction first observed by Locquin in 1906 and independently treated later by Bougault. These authors have shown that semi-carbazones of -keto acids (49) are cyclized under the influence of aqueous sodium hydroxide directly to the 6-substituted 2,5-dioxotetra-hydro-l,2,4-triazines (50). The reaction was usually carried out at... 

There seems, however, to-day, to be overwhelming evidence that the French chemists were correct and that citronellol and rhodinol are two very similar, but chemically different, compounds, citronellol being represented by the formula (1) and rhodinol by formula (2). Considerable evidence of this is to be found in the work of Barbier and Locquin. Starting from the acetic esters of ordinary d-citronellol and rhodinol from oil of geranium or rose, they attached hydrogen chloride to the double bond, and obtained the same additive product according to the equations — ... 

Locquin, M. Plaque de phase a absorption reglable en lumiere polaris6e. 

Bouveault and Locquin have also synthesised leucine by the reduction of a-oximinoisobutylacetic acid, which was prepared in a similar way to the isomeric compound from which they obtained isoleucine. 

Further proof that isoleucine has this constitution was given by Bouveault and Locquin in 1906. They synthesised it from sec. butyl-acetoacetic ester, which they prepared from sec. butyliodide and sodium-acetoacetic ester —... 

Locquin has since obtained d-isoleucine from this racemic compound which was identical with Ehrlich s natural product, and this therefore has the above constitution. 

Fischer and his pupils have thus prepared the optically active forms of leucine, phenylalanine, and valine, and also of phenylaminoacetic acid, and Locquin has prepared, by means of the formyl derivative, d-isoleucine. 

Phenylalanine. Schulze and Barbieri i88i Locquin Erlenmeyer 1905 d Locquin. 1907... 

L. Bouveault et R. Locquin. Hydrogenation des ethers a-oximides synthese des homo-logues du Glycocolle et de leurs ethers. Bull. Soc. Chim., 1904, [iii], 31, 1176-1180. L. Bouveault et R. Locquin. Nouvelle synthise de la leucine racemique. Bull. Soc. 

R. Locquin. Dcdoublcment de I acide a-amino-B-methyl-B-ethylpropionique en ses deux inverses optiques. Bull. Soc. Chim., 1907, [iv], i, 595-601. 

Barbier-Wieland Degradation (Barbier-Locquin Degradation)... 

The method of Bouveault and Locquin,9 which consists of oxidizing cyclohexanol with concentrated nitric acid, has been found to be the most useful for laboratory preparation. 

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