for the following products
(2,5-Dioxopyrrolidin-1-yl) (2S)-2-[(2-methylpropan-2-yl)oxycarbonylamino]-3-phenylmethoxypropanoate | Boc-L-Ser(Bzl)-OSu | N-alpha-tert-Butyloxycarbonyl-o-benzyl-L-serine succinimidyl ester | N-S-tert-Boc-o-Benzyl-L-serine-hydroxysuccinimidester and Boc-Ser(Bzl)-OSu
