118712-64-4Relevant articles and documents
Lipase-catalyzed enantiomer separation of 3-hydroxy-4-(tosyloxy) butanenitrile: Synthesis of (R)-GABOB (=(3R)-4-amino-3-hydroxybutanoic acid) and (R)-carnitine hydrochloride (= (2R)-3-carboxy-2-hydroxy-N,N,N-trimethylpropan- 1-aminium chloride)
Kamal, Ahmed,Khanna, G. B. Ramesh,Krishnaji, Tadiparthi
, p. 1723 - 1730 (2008/03/12)
Enzymatic resolution of racemic 3-hydroxy-4-(tosyloxy)butanenitrile ((±)-5) by using various lipases in different solvents were studied. The obtained optically pure (3R)-3-(acetyloxy)-4-(tosyloxy)-butanenitrile ((R)-6), upon treatment with aqueous ammonia followed by cone. HCl solution, provided (R)-GABOB (=(3R)-4-amino-3-hydroxybutanoic acid; (R)-1). Similarly, reaction of (R)-6 with aqueous trimethylamine solution followed by cone. HCl solution provided (R)-carnitine hydrochloride (=(2R)-3-carboxy-2-hydroxy-N,N,N- trimethylpropan-1-aminium chloride; (R)-2·HCl) in an expeditious manner.
Ring-opening of glycidyl derivatives by silanes mediated by Ti(O-i-Pr)4 or Al(O-i-Pr)3: Access to versatile C3 building blocks
Sutowardoyo,Sinou
, p. 437 - 444 (2007/12/18)
Ring-opening of chiral glycidol or glycidyl tosylate by Me3SiN3 or Me3SiCN catalyzed by Ti(O-i-Pr)4 or Al(O-i-Pr)3 occurred in a regiospecific manner and with very high stereoselectivity, leading to new trifunctionalized chiral building blocks. The enantiomeric excess of the ring-opened products was 90-95%, as determined by 1H NMR of the Mosher ester derivatives, indicating that there was no significant loss of optical purity during the ring-opening. This methodology was applied for the one-pot synthesis of (R)-1-azido-3-naphthyloxy-2-hydroxypropane in 94% ee, a precursor of analogs of propranolol.