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Diastereoisomerism of Thiol Complexes of Arsenic Acids and Pseudoasymmetry of Arsenic: A 1H and 13C NMR Study

John S Edmonds, Takashi Nakayama, Takuya Kondo, Masatoshi Morita

Magn Reson Chem. 2006 Feb;44(2):151-62.

PMID: 16358296

Abstract:

Diastereoisomeric complexes of methylphenylarsinic acid and (L)-glutathione could be partially separated by HPLC, but the separated compounds rapidly racemized, presumably by pyramidal inversion at the arsenic atom. Hydrolysis of the diastereoisomeric complexes yielded methylphenylarsinous acid as a pair of enantiomers revealed by a 1H NMR study with an asymmetric lanthanide shift reagent. Methylphenylarsinous acid was also synthesized as an enantiomeric pair, shown by an asymmetric shift reagent experiment, by the hydrolysis of iodomethylphenylarsine. 1H and 13C NMR spectroscopy were used to demonstrate that complexing of phenylarsonic acid with (R,S)-3-mercapto-1,2-propanediol and with (R,S)-1-mercapto-2-propanol yielded, in each case, a pair of enantiomers, PhAs[(R)-ligand)]2, PhAs[(S)-ligand)]2, in which the homomorphic ligands were diastereotopic, and a pair of diastereoisomers, PhAs[(R)-ligand][(S)-ligand], which differed from each other in the configuration about the pseudoasymmetric arsenic atom.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP1068479 1-Mercapto-2-propanol 1-Mercapto-2-propanol 1068-47-9 Price
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