Homo‐oligohistidines

Conformational studies (CD, i.r., 1H n.m.r.) are reported for a series of N(α)‐t‐butoxycarbonyl, N(π)‐benzyloxymethyl‐homo‐oligo‐L‐histidine methyl esters ranging from the dipeptide to the heptapeptide. In chloroform at high dilution the extent and stability of intramolecularly hydrogen‐bonded folded forms were assessed as a function of chain length. In this low‐polarity solvent at high concentration the heptapeptide adopts a well developed intermolecularly hydrogen‐bonded β‐structure. In polar solvents such as 1,1,1,3,3,3,‐hexafluoro‐propan‐2‐ol and dimethylsulphoxide, unordered solvated forms were found to predominate.