Conversion of Hydroxyproline "Doubly Customizable Units" to Hexahydropyrimidines: Access to Conformationally Constrained Peptides.

The efficient transformation of hydroxyproline "doubly customizable units" into rigid hexahydropyrimidine units takes place in good global yields and generates compounds of pharmaceutical interest. In particular, the process can readily provide access to peptidomimetics and peptides with reversed sequences or with valuable turns.