3- Amino-2-hydroxy-5-methylhexanoic acid

A different study generated the lithium imine of 2.118 and condensed it with ester 2.119 to give 2.120. Deprotection of the lactam nitrogen with ceric ammonium nitrate and acid hydrolysis led to formation of 3-amino-2-hydroxy-5-methylhexanoic acid, 2.727.57... 

S,4S,5 E,7E)-3-Amino-4-hydroxy-6-methyl-8-(4-bromophenyl)-octa-5,7-dienoic acid [Aboa = Br-Ahmp, Br-Apoa], (2S,3S,8S,9S)-3-Amino-9-methoxy-2,6,8-trimethyl-10-phenyl-deca-4,6-dienoic acid (Adda). 3-Amino-2,4-dimethylpentanoic acid (Admpa). (2S,3R,5S)-3-amino-2,5,9-trihydroxy-10-phenyldecanoic acid (Ahda). j3-Aminoisobutyric acid (jS-AiB). (3S,4S,5E,7E)-3-Amino-4-hydroxy-6-methyl-8-phenylocta-5,7-dienoic acid [Ahmp (Faulkner) or Apoa (Fusetani)]. (2S,3R,5R)-3-Amino-2,5-dihydroxy-8-phenyloctanoic acid (Ahoa). 3-Aminopentanoic acid (Apa /5-Apa). (2R,3R)-3-Amino-2-methylbutanoic add (Amba). 3-Amino-2-methylhexanoic acid (Amha). 3-Amino-2-methyl-7-octynoic add (Amoa, Amoya). 3-Amino-7-octynoic add (Aoya). (2S,3R)-3-Amino-2-methylpentanoic acid (Map). http // www.ncbi.nlm.nih.gov/ Taxonomy/ tax.html... 

The structure of YA-56 was studied by Ohashi et al.36l. They showed that structural differences between PHM and YA-S6 existed in amine components I and III, and in the gulose moiety. They axe substituted by /3-hydroxy-L-valine, 4-amino-3,6-dihydroxy-2-methylhexanoic acid and 6-deoxy-L-gulose, respectively. The terminal amine was found to be 3-aminopropionamidine, which had not been found in natural PHMs. The total structure of YA-56X can be postulated as shown in Fig. 928.36) YA-56 Y has an additional component, 7-aminobutyric acid. But the position of this amino acid in the molecule is not yet known. 

LeuMstin [(2/(,35)-3-amino-2-hydroxy-2-(IA/-imida-zol-4-ylmethyl)-5-methylhexanoic acid]. 

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