Synthesis of New Photoactivatable Phenylalanine Analogues and Their Incorporation into a Model Peptide − Phenylseleno Derivatives as Precursors of α,β-Unsaturated Ketones in Peptide Synthesis
The asymmetric synthesis of (S)-Boc-p-(propanoyl)phenylalanine (10) was performed by alkylation of sultam N-(diphenylmethylene)glycinate (4). Different pathways for the introduction of a phenylseleno moiety α to the ketone function were investigated. (S)-Boc-p-[2′-(phenylselenenyl)propanoyl]phenylalanine (11) was easily obtained from (S)-Boc-p-(propanoyl)phenylalanine (10). However, the phenylseleno