LINEAR OLIGOPEPTIDES .59. STEREOCHEMICAL ANALYSIS OF N-TERT-BUTYLOXYCARBONYL-L-PROLYLSARCOSINE AND N-TERT-BUTYLOXYCARBONYLSARCOSYLSARCOSINE IN THE SOLID-STATE AND IN SOLUTION

An analysis of the conformational properties of N-tert-butyloxycarbonyl-L-prolylsarcosine and N-tert-butyloxycarbonylsarcosylsarcosine was carried out in the solid state and in solution. The stereochemical preferences of the two N-protected dipeptides were found to be close under the experimental conditions examined. In the solid state a cis tertiary urethane bond and an intermolecular O-H…0̳C (amide) hydrogen bond characterize the molecular and crystal structures. Even in a solvent of low polarity at high dilution the amounts of intramolecularly hydrogen-bonded forms, if any, appear to be negligible. © 1979, American Chemical Society. All rights reserved.