S-Trimethylacetamidomethyl-L-cysteine Cys(Tacm)] was easily prepared from N-hydroxymethyltrimethyl-acetamide and L-cysteine in trifluoroacetic acid. The S-Tacm group is stable to HF, but cleavable with mercury(II) acetate in trifluoroacetic acid or iodine in aqueous acetic acid. Cys(Tacm) is less susceptible to sulfoxide formation than three related groups, i.e., acetamidomethyl (Acm), benzamidomethyl (Bam) and (2-oxo-1-pyrrolidinyl)methyl (Pym).
S-三甲基乙酰胺甲基-
L-半胱氨酸(Cys(Tacm))可轻松地由N-羟甲基三甲基乙酰胺和
L-半胱氨酸在
三氟乙酸中制备。S-Tacm基团对
氢氟酸稳定,但可以被
乙酸汞(II)在
三氟乙酸中或
碘在
乙酸水溶液中裂解。与三种相关基团,即乙酰胺甲基(Acm)、苯甲酰胺甲基(Bam)和(2-氧-1-
吡咯烷基)甲基(Pym)相比,Cys(Tacm)更不容易形成亚砜。