Alpha-azido acids for direct use in solid-phase peptide synthesis

Several new alpha-azido acids have been synthesized and their use in solid-phase peptide synthesis has been demonstrated. The azido group allows for high activation of the carboxyl group as an acid chloride without formation of byproducts and with no detectable racemization. An analog of Leu-enkephalin has been prepared and tested in the mouse vas deferens and guinea pig ileum bioassays: it displays moderate activity at the delta-opiod receptor.