The present invention is directed to certain novel compounds represented
by structural Formula (I) ##STR00001## or pharmaceutically acceptable
salt forms thereof, wherein R.sup.1, R.sup.5, R.sup.6a, R.sup.6b,
R.sup.7, R.sup.8, R.sup.9, X, b, k, m, and n, and the dashed lines are
described herein. The invention is also concerned with pharmaceutical
formulations comprising these novel compounds as active ingredients and
the use of the novel compounds and their formulations in the treatment of
certain disorders. The compounds of this invention are serotonin agonists
and antagonists and are useful in the control or prevention of central
nervous system disorders including obesity, anxiety, depression,
psychosis, schizophrenia, sleep disorders, sexual disorders, migraine,
conditions associated with cephalic pain, social phobias, and
gastrointestinal disorders such as dysfunction of the gastrointestinal
tract motility.