Cyano hydrins

Cham extension by way of cyano hydrin formation (Section 25 20)... 

Glycine and the other amino acids are probably formed via the Strecker-cyano-hydrin synthesis (which has been known for more than 150 years) from aldehyde, HCN and ammonia, with subsequent hydrolysis (Strecker, 1850,1854 Miller, 1953). 

More successfully, the (S)-Hnl from Manihot esculenta has also been overexpressed in E. coli [41] and the lysate of the transformed cells showed an enzyme activity of 0.5 units per ml of the culture. A culture of 801 volume of the recombinant MeHnl followed by a short purification procedure [41] yielded 40,000 U. To obtain the equivalent amount of enzyme from the parent plant material would require the processing of 100 -200 kg of dried cassava leaves and thus this recombinant method for the production of MeHnl is a significant practical development. Hence, this recombinant MeHnl has allowed a study of (S)-cyano-hydrin production to be performed [41]. 

Scheme 6.6 DCL-D Five benzaldehyde derivatives (23-27) and acetone cyano-hydrine (28), forming cyanohydrin adducts (29-33).

Reduction of oxonitriles (Method D) may afford either phenethylamines or phenylethanolamines, depending on the reaction conditions (311, 312). Alternative methods for the synthesis of phenylethanolamines are exemplified by reduction of 2-aminoacetophenones (Method E) (313) or by reduction of cyano-hydrines (Method F) (314). Octopamine has been recently synthesized in high yield via a BH3 THF-catalyzed reduction of a trimethylsilyl cyanide adduct (Method G) (315). Two other amino alcohols were synthesized in similar yields, suggesting that this method is of general value for the preparation of this class of compounds. 

Discovery of the diuin lcngthening sequence was initiated by the observation of Heinrich Kiliani in 1686 Uiat uldoses react with HCN to form cyanohydrins iSeaion 19.7i. Emil Fischer immediately realised the importance c Kilinni s discovery and devised a metliod for converting the cyano-hydrin nitrile group into an aldehyde. 

U. Neidermyer and M.-R. Kula, Enzyme-catalysed synthesis of (S)-cyano-hydrins, Angew. Chem. Int. Ed. Engl., 29 386 (1990). 

Acetone Cyano- hydrin 165 2.2 12 Water spray, dry chemical, alcohol foam or carbon dioxide Not pertinent Not pertinent 1270 No ... 

I. Aldolic addition and the Mannich reaction (Vol. I. p. 186) The aldolic I addition reaction of nitroalkanes with carbohydrates (specifically aldoses) continues to be an important reaction in sugar chemistry which according to Baer i ) in some respects surpasses in versatility limil Fischer s classical cyano-[hydrin syntliesis. Particularly noteworthy are publications by Baer and Kovaf 1144, 45], Funubaski. Yoshimura and co-workers (46 51] and other Japanese [workers (52], Russian workers [53, 54] and Bilik (55]. 

The haloketal cyclization is most useful for synthesis of polycyclic systems. Thus (5) is converted into a < b-9-cyano-2-decalone (6), and (7) is converted into (8). The hydrin-dane (10) was prepared from (9). 

ANTIREN (110-85-0) Combustible solid (flash point I90°F/88°C). Dust or powder forms explosive mixture with air. Violent or explosive reaction with strong oxidizers, strong acids, dicyanofurazan, 3-(3-cyano-l,2,4-oxadiazol-5-yl)-4-cyanofurazan-2-(5-)oxide. Reacts with nitrogenous compounds, carbon tetrachloride. Aqueous solution is a strong base. Incompatible with alcohols, aldehydes, alkylene oxides, alkalis, cresols, caprolactam solution, epichloro-hydrin, organic anhydrides, glycols, maleic anhydride, phenols. Attacks aluminum, cobalt, copper, nickel, magnesium, and zinc. 

---