Braconnot

Natural Occurrence of ( — )-proto-Quercitol. Although the dextrorotatory form (12) of proto-quercitol was discovered in acorns more than a century ago by Braconnot (5), who at first thought that it was lactose, the levorotatory form (13) remained unknown until 1961. In that year, Plouvier isolated it from leaves of the tree Eucalyptus populnea the yield was 0.55% (36). The optical rotation of the new compound was equal and opposite to that of the dextro enantiomer, and it was identical to the latter in its crystal form, melting point, solubilities, molecular formula and infrared spectrum. 

In 1833 Braconnot obtained nitric esters of cellulose and starch by acting with nitric acid on plant fibres and starch, at low temperature. 

Braconnot, who first nitrated cellulose, was also the first to nitrate starch, in 1833 (Ref 1). 

Pyroxalam. The name given by Uchatius in the 1830 s to a white powder obtained by nitrating starch with a mixt of nitric and sulfuric acids, and which contained about 11.1% N. It was Nitrostarch (see in this Vol) with the formula C2 4H320l2(0N02)8, and closely resembled a product previously prepd (1832) by Braconnot by treating starch with neat coned nitric acid Ref Daniel (1902), 459, under Nitramidon... 

Records indicate that Braconnot was interested in the dilute-acid method of hydrolysis as early as 1819. Many other workers have made contributions, but it was not until 1898 that an attempt was made to commercialize the process. At that time Simonsen published a paper on the process. His process consisted in treating sawdust for fifteen minutes with four parts of 0.5% sulfuric acid at about 9 atmospheres pressure. He obtained a 6 % yield of sugar, based on dry wood. 

Leucine. Proust. Braconnot i8i8 1820/ 1 Limpricht. I Schulze and V Likiernik. i855" 1885/ 1 >> 1900... 

Boussingault. Sur la Composition du sucre de gelatine et de I acide nitrosaccharique de Braconnot. Compt. rend., 1838, 7, 493-495. 

H. Braconnot. Sur la Conversion des matieres animales en nouvelles substances par le moyen de Vacide sulfurique. Ann. de Chim. et de Phys., 1820, 13, 113-125. 

Nitrostarch (NS) was first prepd by Braconnot, who called it xyloidine. Pelouze prepd it, in 1838, in purer condition and studied its props. It was used in the US during WWI and WWII as demolition expl and for bursting charges (Ref 70, pp 246 to 248)... 

The first important invention before the invention of NC NG was the prepn in 1833 of impure Nitrostarch(NS) by Braconnot. The next step was prepn in 1838 by Pelouze of nitrated paper and cotton, but it was not realized that these were actually impure, low nitrogen content, NC s. More important than the work of the above investigators were the prepn in 1846 of NC of high N content (known as Guncotton), independently by C.F. Schonbein (1799 1866) and F. Bottger (1806 1886) and in the same year of NG by an Italian chemist Ascanio Sobrero (1812-1888). The method of prepn and some props of NG were published in France in Feb 1847 by Th-J. Pelouze (1807-1867)... 

At the same time as nitroglycerine was being prepared, the nitration of cellulose to produce nitrocellulose (also known as guncotton) was also being undertaken by different workers, notably Schonbein at Basel and Bottger at Frankfurt-am-Main during 1845-47. Earlier in 1833, Braconnot had nitrated starch, and in 1838, Pelouze, continuing the experiments of Braconnot, also nitrated paper, cotton and various other materials but did not realize that he had prepared nitrocellulose. With the announcement by Schonbein in 1846, and in the same year by... 

Col crysts, mp 232-6° (decomp), d 1.161. Very sol in w, si sol in ale, insol in eth. Was obtained in 1820 by Braconnot by treating isinglass (fish glue) with HaS04(Ref 2). Can also be prtpd by the action of coned NH4OH on monochloroacetic acid as well as by alkaline hydrolysis of gelatine, etc... 

Xyloidine. Name given by Braconnot to the product obtained by him in 1833 on the nitration of starch. It was Nitrostarch with a N content below 11%. See under Nitrostarch in Vol 8, N158-L... 

Pelouze [2] continued the investigations of Braconnot by subjecting paper or cotton to the action of nitric acid. The difference was that in his experiments the nitrated material was not dissolved in nitric add, but the product was similar. In later papers it was described under the name of pyroxylin. Extending his earlier researches, Pelouze [3] later established that pyroxylin was a substance differing in prindple from the product obtained by nitrating starch. 

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