Fmoc-OSu has been widely used for Fmoc protection of amino groups, especially amino acids, in solid phase peptide synthesis. However, it has been recognized that Fmoc-βAla-OH is formed as a by-product via the Lossen rearrangement during the reaction. Since we reconfirmed the formation of Fmoc-βAla-OH during the preparation of Fmoc-AA-OH by Fmoc-OSu, Fmoc-OPhth was designed and synthesized as a new Fmoc reagent to avoid the formation of Fmoc-βAla-OH. Furthermore, Fmoc protection by Fmoc-OPhth and Fmoc-SPPS were evaluated. The various Fmoc-amino acids prepared by Fmoc-OPhth were carried out in good yields and these are applicable in Fmoc-SPPS.

中文翻译：

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Fmoc-OPhth，Fmoc保护的试剂

Fmoc-OSu已被广泛用于固相肽合成中氨基，尤其是氨基酸的Fmoc保护。然而，已经认识到，Fmoc-βAla-OH是在反应过程中经由洛森重排形成的副产物。由于我们在通过Fmoc-OSu制备Fmoc-AA-OH的过程中再次确认了Fmoc-βAla-OH的形成，因此设计并合成了Fmoc-OPhth作为一种新的Fmoc试剂，从而避免了Fmoc-βAla-OH的形成。此外，还评估了Fmoc-OPhth和Fmoc-SPPS对Fmoc的保护作用。由Fmoc-OPhth制备的各种Fmoc-氨基酸均以良好的收率进行生产，可用于Fmoc-SPPS。