?Boc-Cys(Acm)-OH?,?its cas register number is?19746-37-3.?It also can be called as N-Alpha-tert-Butyloxycarbonyl-s-(acetyl-aminomethyl)-l-cysteine ; n-Alpha-t-Butoxycarbonyl-s-acetamidomethyl-l-cysteine ; n-Alpha-t-Butyloxycarbonyl-s-(acetyl-aminomethyl)-l-cysteine ; n-Alpha-t-Boc-s-acetamidomethyl-l-cysteine ; n-Boc-s-acetaminomethyl-l-cysteine ; (r)-3-(Acetylamino-methylsulfanyl)-2-tert-butoxycarbonylamino-propionic acid ; t-Butyloxycarbonyl-s-acetamidomethyl-l-cysteine ;? and Boc-s-acetaminomethyl-l-cysteine .