Stereoselective synthesis of Gly-Gly-type ( E )-methylalkene and ( Z )-chloroalkene dipeptide isosteres and their application to 14-mer RGG peptidomimetics.

Stereoselective and efficient synthesis of Gly-Gly-type ( E )-methylalkene and ( Z )-chloroalkene dipeptide isosteres is realized by organocuprate-mediated single electron transfer reduction. The synthetic isosteres can be used in Fmoc-based solid phase peptide synthesis, resulting in the preparation of the 14-mer RGG peptidomimetics containing an ( E )-methylalkene or a ( Z )-chloroalkene unit.