We describe an efficient synthesis of highly active renin inhibitors containing a sulfonemethylene isostere at their N-terminals and a hydroxyethylene isostere at their C- terminals. The stereospecific synthesis of N-terminal key intermediate, LN-[(2R)-2-benzyl (or 1-naphthylmethyl)-3-hydroxypropionyl] norleucine t-butyl ester is described.