Abstract
The modification of amino acids leads to valuable building blocks for the synthesis
of bioactive compounds. By keeping the amino group protected, the carboxylic acid
functionality can be converted in two steps into an imidazole moiety via a Davidson-like
heterocyclization. This reaction allows for a combinatorial approach, in which two
positions at the heterocycle can be modified. Herein, we report the synthesis of such
imidazole derivatives by employing N-protected cyclohexylalanine as the starting material.
Different α-halo ketones were used and two points of diversity, positions 4 and 5,
were examined. The structure of the final imidazole derivatives was confirmed by three
X-ray crystal structure analyses and their protease inhibiting activities were evaluated.
Key words
amino acids - Davidson synthesis - heterocycles - imidazoles - X-ray crystal structure
analysis
