Compounds useful as inhibitors of PDE4 in the treatment of diseases regulated by the activation and degranulation of eosinophils, especially asthma, chronic bronchitis, and chronic obstructive pulmonary disease, of Formula (1.0.0): ##STR00001## wherein R.sup.5 and R.sup.6 are taken together to form a moiety of partial Formulas (1.1.1) through (1.1.5): ##STR00002## or a pharmaceutically acceptable salt thereof.