Fmoc-Cys(Acm)-OH , its cas register number is 86060-81-3. It also known as FMOC-L-Cys ; Fmoc-S-acetamidomethyl-L-cysteine ; and N-alpha-(9-Fluorenylmethyloxycarbonyl)-S-(acetyl-aminomethyl)-L-cysteine .