An efficient synthesis of enantiopure Fmoc-α-methylvaline has been developed. The racemate was prepared in two steps from 3-methyl-2-butanone and was resolved using a chiral amine,(S)-1, 2, 3, 4-tetrahydro-1-naphthylamine to give the desired, enantiopure S- isomer in 23% overall yield.
