Preparation of the β2-Homoselenocysteine Derivatives Fmoc-(S)-β2hSec(PMB)-OH and Boc-(S)-β2hSec(PMB)-OH for Solution and Solid-Phase Peptide Synthesis

摘要

Fmoc-β2hSer(tBu)-OH was converted to Fmoc-β2hSec(PMB)-OH in five steps. To avoid elimination of HSeR, the selenyl group was introduced in the second last step (Fmoc-β2hSer(Ts)-OAll→Fmoc-β2hSec(PMB)-OAll). In a similar way, the N-Boc-protected compound was prepared. With the β2hSe-derivatives, 21 β2-amino-acid building blocks with proteinogenic side chains are now available for peptide synthesis.