Rink, Hans published the artcileConversion of NG-urethane protected arginine to ornithine in peptide solid-phase synthesis, Product Details of C19H21N, the publication is Tetrahedron Letters (1984), 25(6), 621-4, database is CAplus.
During solid-phase peptide synthesis, guanidino protection by adamantyloxycarbonyl (Adoc) or Me3CO2C (Boc) groups does not effectively prevent guanidino acylation and subsequent partial conversion of arginine residues to ornithine residues when strongly basic conditions are used to remove α-amino protecting groups. Thus, Z-Phe-Ser(CMe3)-Leu-Ser(CMe3)-Lys(Boc)-Ile-Phe-Gln-Glu(OCMe3)-Arg(Adoc)2-Leu-Arg(Adoc)2-Arg(Adoc)2-Lys(Boc)-Glu(OCMe3)-OCH2-resin (I, Z = PhCH2O2C, CH2-resin = acid-labile p-benzyloxybenzyl alc. resin) was prepared by the solid-phase method using 9-fluorenyloxycarbonyl (Fmoc) amino acids and then I was cleaved and deblocked to give Z-Phe-Ser-Leu-Ser-Lys-Ile-Phe-Gln-Glu-X-Leu-Orn-Arg-Lys-Glu-OH (X = Orn, Arg). The above arginine to ornithine conversion was confirmed by the following model reactions. Boc-Arg(Adoc)2-OMe was treated with (Fmoc-Phe)2O to give arginine II, which was Fmoc-deblocked by piperidine/DMF to give Boc-Orn(Adoc)-OMe, fluorene III, and imidazolinone IV.
Tetrahedron Letters published new progress about 35661-58-6. 35661-58-6 belongs to piperidines, auxiliary class Piperidine,Benzene, name is 1-((9H-Fluoren-9-yl)methyl)piperidine, and the molecular formula is C19H21N, Product Details of C19H21N.
Referemce:
https://en.wikipedia.org/wiki/Piperidine,
Piperidine | C5H11N – PubChem