Abstract: Methods of use of compounds and compounds for the treatment of disorders characterized by the cerebral deposition of amyloid are provided. Among the compounds are those of formulae (I), (II) and (III): ##STR1## in which R.sub.1 is preferably 2-methyl propene, 2-butene, norleucine; R.sub.2, R.sub.4, and R.sub.8 are each independently methyl or ethyl; R.sub.3 is preferably iso-butyl or phenyl; R.sub.5 is preferably iso-butyl; R.sub.6 is H or methyl; R.sub.7 --(Q).sub.n is preferably benzyloxycarbonyl or acetyl; Q is preferably --C(O)--; R.sub.8 is preferbly iso-butyl; R.sub.A =--(T).sub.m --(D).sub.m --R.sub.1, is which T is preferably oxygen or carbon, and D is preferably a mono-unsaturated C.sub.3-4 alkenyl being more preferred; and X is an alcohol, particularly a secondary alcohol.