α-(Phenylacetamido)benzylpolystyrene (pab-resin)

The synthetic viability of the chloromethyl-Pab-resin is shown by the synthesis of Ac-His-Arg-Tyr-Arg-Pro-OH (fragment 39-43 of histone H3). The synthesis and subsequent purification are exhaustively compared with the parallel synthesis carried out on a standard chloromethyl polystyrene support. The presence of the acetamido linkage provokes, as expected, a decrease in the HF cleavage yield. Nevertheless, this disadvantage is balanced by the increase in global purification yields even for the synthesis of a pentapeptide for which only five deprotection steps are required.