Efficient large (ca. 40 g) laboratory scale preparation of (S)-and (R)-valine tert-butyl esters
…, GL Levit, IM Bukrina, AM Demin, ON Chupakhin…
文献索引：Krasnov, Victor P.; Levit, Galina L.; Bukrina, Iraida M.; Demin, Alexander M.; Chupakhin, Oleg N.; Yoo, Ji Uk Tetrahedron Asymmetry, 2002 , vol. 13, # 17 p. 1911 - 1914
A large laboratory scale (ca. 40 g) method for the preparation of enantiomerically pure (S)- and (R)-valine tert-butyl esters has been developed. The method involves three steps: preparation of N-TFA-valines, preparation of valine tert-butyl esters using 2-methylpropene in dioxane in the presence of sulfuric acid, and isolation of the target compounds as the acetate derivative. The overall yield is up to 70% relative to the starting valine, ee being ...
