Asymmetric synthesis of a conformationally constrained N-phosphonoalkyl dipeptide

An asymmetric synthesis has been developed to prepare a phosphono-protected (2S,6R)-6-phosphono-piperidine-2-carboxylic acid and its (2R, 6S) isomer. Coupling qith tryptophan derivative afforded conformationally constrained N-phosphonoalkyl dipeptides (S,S,R)-2 and (S,R,S)-14 which have been both evaluated as human matrix metalloprotease inhibitors.