CAS 4467-55-4 appears in our catalog under these names: (R)–2,5–Dioxopyrrolidin–1–yl 2–(((benzyloxy)carbonyl)amino)–3–methylbutanoate, Z-D-Val-OSu 97%, (R)-2,5-Dioxopyrrolidin-1-yl 2-(((benzyloxy)carbonyl)amino)-3-methylbutanoate, 97%, 97%, Z-D-valine N-hydroxysuccinimide ester, 97%. Offered by: GLPBio, Ambeed, Chemat, Fluorochem. Available pack sizes: 10g, 25g, 5g, 1g, 100g, 500g.