Synthesis of cyclic peptidomimetics from aldol building blocks

Aldol products (3-hydroxy acids) with an allyl-protected hydroxy group were converted to amino alcohols by Curtius rearrangement. Combination of the carboxylic acid with the amino alcohols gave the amides 10. Ring-closing metathesis led to the 12-membered lactams 12 as mixtures of E/Z-isomers. The scheme was also transferred to the solid-phase. In this case the macrolactams are formed via cyclorelease. For a pair of E/Z-isomers the solution conformation was determined by ROESY spectroscopy.