Reversible backbone protection enables combinatorial solid-phase ring-closing metathesis reaction (RCM) in peptides.

ABSTRACT

[reaction see text] Attempts were made to apply the ring-closing metathesis reaction (RCM) to resin-bound peptides with olefinic side chains of different lengths. In a protein-derived homodetic 10mer peptide epitope the RCM reaction did not take place at all. Only by the introduction of the secondary structure disrupting reversible backbone protection Ser(Psi(Me,Me)pro) and subsequent optimized reduction and purification protocols were we able to generate a full set of RCM cyclized peptides.