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Synthesis of 2 H, 13 C, 15 N‐isotomers of branched‐chain amino acids(1)
Author(s) -
Kor SunShine Yuan
Publication year - 1983
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580200205
Subject(s) - chemistry , strecker amino acid synthesis , ammonium hydroxide , leucine , amide , valine , amino acid , isoleucine , stereochemistry , hydrolysis , organic chemistry , enantioselective synthesis , biochemistry , catalysis
Synthetic schemes for 2(S,R)‐amino‐3‐[D 3 ](R,S)methylpentanoic acid, 2(S,R)‐amino‐3‐[ 13 C](R,S)methyl‐[4‐ 13 C]pentanoic acid (isoleucine) and [1‐ 13 C, 15 N](S)‐leucine are described. The side chain labeled isoleucines were constructed by first alkylating 2,4,4‐trimethyl‐2‐oxazoline with appropriate labeled alkyl halides and then reducing the resultant oxazolines to the aldehydes. Strecker synthesis yielded a mixture of isoleucine and alloisoleucine which was separated via the N‐acetyl derivatives. In a separate sequence, Strecker synthesis using 3‐methylbutanal, [ 13 C]cyanide and [ 15 N]ammonium hydroxide, followed by acid hydrolysis, gave [1‐ 13 C, 15 N]leucine amide. This amide was resolved by leucine aminopeptidase to produce [1‐ 13 C, 15 N](S)‐leucine. Similar schemes were used for the synthesis of [1‐ 13 C] or [ 15 N](S)‐leucine and [1‐ 13 C] or [ 15 N](S)‐valine.