Solid-Phase Synthesis Using (Allyloxy)carbonyl(Alloc) Chemistry of a Putative Heptapeptide Intermediate in Vancomycin Biosynthesis Containing m-Chloro-3-hydroxytyrosine

A convenient method for the solid-phase synthesis of putative linear heptapeptide intermediates in vancomycin biosynthesis is described, in particular, the heptapeptide D-Leu-Cyt-L-Asn-Hpg-Hpg-Cyt′-Dhpg (Cyt=(2R,3R)-m-chloro-3-hydroxytyrosine, Hpg=(R)-2-(p-hydroxyphenyl)glycine, Cyt′=(2S,3R)-m-chloro-3-hydroxytyrosine and Dhpg=(S)-2-(3,5-dihydroxyphenyl)glycine). The synthesis was performed on chlorotrityl resin and employed the (allyloxy)carbonyl protecting group for temporary N(α) protection during peptide-chain assembly.