Following the success of the p-hydroxyphenacyl (pHP) phototrigger as an efficient photoprotecting group for a variety of functional groups, its utilization in a traceless reagent release of combinatorial libraries is explored. Photoreleasable protecting groups has also received attention in solid phase organic synthesis due to ease of release and the potentially facile separation of polymer and product. Synthesis of a library of pHP caged maleimide derivatives of available amino acids (1) is in progress. Diels-Alder reactions with the maleimide dienophile provide additional diversification. For example, cyclopentadiene yields norbornene handles that can be used in ring opening metathesis polymerization (ROMP). The photorelease of 2 will also free a functional group (carboxylic acid) that can be used for further elaboration. The synthesis and the photolysis of the glycine and phenylalanine derivatives are being investigated.