5UDP:
reference: Scope and Limitations of Fmoc Chemistry SPPS-Based Approaches to the Total Synthesis of Insulin Lispro via Ester Insulin., Dhayalan B, Mandal K, Rege N, Weiss MA, Eitel SH, Meier T, Schoenleber RO, Kent SB, Chemistry. 2016 Nov 30. doi: 10.1002/chem.201605578. PMID: 27905149

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