Synthesis and properties are reported for a number of peptides and related derivatives of 3‐hydroxy‐L‐proline and 4‐hydroxy‐L‐proline. These were made for several different purposes, namely, synthesis of N‐acetyl‐O‐tosyl‐4‐hydroxy‐L‐proline amide as a model for chemical reduction of peptide‐bound hydroxyproline, synthesis of tripeptides with the sequence glycyl‐4‐hydroxy‐L‐prolyl‐X, synthesis of the naturally occurring sequence, glycyl‐3‐hydroxy‐L‐prolyl‐4‐hydroxy‐L‐proline, and monomers for polymerization to yield the sequence ‐glycyl‐prolyl‐4‐hydroxy‐L‐prolyl‐.