Compounds of the formula ##STR1## wherein X is various amino or imino acids and esters are disclosed. These compounds are useful as anti-hypertensive agents due to their angiotensin converting enzyme inhibition activity and depending upon the definition of X may also be useful as analgesics due to their enkephalinase inhibition activity.
We present herein a straightforward synthesis of N-Fmoc-protected synthons derived from a phosphinic analogue of methionine. These precursors were used Successfully for the solid-phase synthesis of methionine-mimic phosphinopeptides using BOP-catalyzed coupling without protection of the phosphoryl moiety. We also prepared a new type of pseudopeptide derived from a phosphinic analogue of norleucine with a -PO(OH)-CH(2)-COOR moiety. (C) 2008 Elsevier Ltd. All rights reserved.