N-Protected amino alcohols and peptide alcohols are important synthetic intermediates, 1
especially useful in the synthesis of peptide aldehydes which are potent inhibitors of
proteases. 2 Some biologically active pep-tides, eg enkephalins, exhibit better biological
activity when their terminal carboxyl group is reduced to a hydroxymethyl group. 3 N-
protected amino and peptide alcohols can be prepared by reduction of alkyl esters of amino
acids “'5 and peptides, 4 and active esters of amino acids “with sodium borohydride. Borane …