A compound of the formula:
##STR1##
or a pharmaceutically acceptable salt thereof, wherein R.sup.1 is
unsubstituted, mono-, di- or tri-substituted (C.sub.3 -C.sub.11)cycloalkyl
or (C.sub.3 -C.sub.11)cycloalkenyl or the like, A is unsubstituted
(C.sub.1 -C.sub.7)alkyl or (C.sub.2 -C.sub.5)alkenyl, hydroxy-(C.sub.1
-C.sub.4)alkyl, (C.sub.1 -C.sub.4)alkoxy-(C.dbd.O), or unsubstituted,
mono-, di- or tri-substituted aryl, or aromatic-heterocyclic or the like,
M is a covalent bond O, S, NH or the like, Y is 4- to 12-membered
bicyclic-carbocyclic rings or 4- to 12-membered bicyclic-heterocyclic
rings, or 5- to 17 membered spirocarbocyclic rings or 5- to 17-membered
spiroheterocyclic rings or the like, Z.sup.1, Z.sup.2, Z.sup.3 and Z.sup.4
are hydrogen or the like, is disclosed. These compounds have ORL1-receptor
agonist activity, and are thus useful as analgesics or the like in
mammalian subjects.
