Amino Ammo acids, synthesis

O DONNELL Ammo Acid Synthesis Amino acid synthesis by alkylation ot glycine denvaiives... 

Ammo acids, synthesis of, 30, 7 2 Amino-4-anilino-6-(chloro... 

As described in the preceding sections protein synthesis involves transcription of the DNA to rtiRNA followed by translation of the mRNA as an amino acid sequence In addition to outlining the mechanics of transcription we have described the relationship among mRNA codons tRNA anticodons and ammo acids... 

Carbamates can be used as protective groups for ammo acids to minimize race-mization in peptide synthesis. Raccmi/ation occurs during the base-catalyzed coupling reaction of an W-protected, catboxyl-uc ivated amino acid, and takes place in the intermediate oxazolone that foro S readily from an N-acyl protected amino... 

T he CCA terminus containing the ammo acid-attachmerit site extends from one end of the L. This single-stranded region can change conformation in the course of amino acid activation and protein synthesis. 

STRECKER Ammo acidsynthesis Synthesis at a-amino acids from aldehydes or ketones via cyanohydnns... 

WILLIAMS - BEN ISHAI Amino acid synthesis Asymmetric synthesis (Williams) ot o-ammo acids through C-C bond constiuctlon on an electfophylic glycine template... 

Watkins J. C. and Evans R. H (1981) Excitatory ammo acid transmitters Ann Rev Pharmacol Toxicol 21, 165-204 Wood J. H, Hare T. A, Galeser B. S, Ballenger C, and Post R M (1979) Low cerebrospinal fluid 7-aminobutyric acid content in seizure patients Neurology 29, 1203-1208 Wurtman, R, J, Hefti, F, and Melamed E. (1981) Precursor control of neurotransmitter synthesis. Pharmacol Rev 32, 315-335 Yamamoto S, Kiyama S., Watanabe Y, and Makita M (1982) Practical gas-liquid chromatographic method for the determination of amino acids m human serum. / Chromatogr 233, 39-50... 

Scheme 16 Synthesis of 5-ammo-6-deoxy- or 6-amino-6-deoxyaldomc acid monomers...

Figure 2.5 Treating an aldehyde with ammonia and hydrogen cyanide produces an df-ammo nitrile. By hydrolysis of the nitrile group an df-amino acid is produced. This synthesis is called the Strecker synthesis.

The a-amino nitrile is formed by reaction of the aldehyde with ammonia or an ammo-ninm salt and a source of cyanide ion. Hydrolysis of the nitrile group to a carboxylic acid function completes the synthesis. 

Qian WJ, Burke TR Jr, Terrence R (2013) Design and synthesis of a reagent for solid-phase incorporation of the phosphothreonine mimetic (2S,3R)-2-ammo-3-methyM-phosphonobutyric acid (pmab) into peptides in a bio-reversible phosphraiyl-bis-pivaloyloxymethyl (POM) prodmg form. Amino Acids 45 1143-1148... 

Ohba and co-workers have demonstrated that A -protected a-amino esters are compatible with the Schollkopf oxazole synthesis cf., 38->39). In the case of ammo esters derived from natural amino acids (e.g., 38), the presence of an additional acidic N-H bond in the AABoc ester substrate necessitated the use of an added excess of metalated isocyanide (2.5 equiv was found to be optimal) to obtain maximal yields. Under optimized conditions, oxazoles (39) were obtained in good yield from iV-Boc glycine, alanine, and phenylalanine. Oxazole formation from iV-Boc serine (which possesses an additional acidic site in its hydroxylic side chain) proceeded in good yield (66%) using 3.5 equiv lithiated methyl isocyanide. Notably, no epimerization was detected in the reaction of N-Boc alanine methyl ester with lithiated methyl or ethyl isocyanide under these conditions. Minor epimerization was observed (91-92% ee product) with substrates that lacked a carbamate NH hydrogen e.g., A -Boc proline methyl ester), however. ... 

Synthesis of Lopinavir and Ritonavir Core In 2007, Menche and co-workers published an asymmetric reductive amination methodology for p-hydroxy ketones 132 for synthesizing a range of l,3-sy -ammo alcohols 135.The reaction was optimized using Ti(Oi-Pr)4 for the coordination of the intermediate imino alcohol 133 and polymethylhydrosiloxane (PMHS) as the hydride source. The reaction was believed to proceed via the initial formation of an imino alcohol that would coordinate to the Lewis acid to undergo reduction through a Zimmerman-Traxler-type transition state 134 to furnish the corresponding iy -l,3-amino alcohol (Scheme 39.40). 

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