?L-tert-Leucine (CAS NO.20859-02-3) is also named as (2S)-2-Amino-3,3-Dimethylbutanoic Acid?; (S)-2-Amino-3,3-dimethylbutanoic acid ; (S)-2-Amino-4-methylpentanoic acid ; 3-Methyl-L-valin ; 3-Methyl-L-valine .?L-tert-Leucine (CAS NO.20859-02-3) is white to almost white powder.