7- or 8-Substituted, partially hydrogenated pyrazolo[3,4-g]quinoline, thiazolo[4,5-g]quinoline, oxazolo[4,5-g]quinoline, and pyrrolo[3,4-g]quinoline derivatives, and 8- or 9-substituted, partially hydrogenated pyrido[2,3-g]quinazoline derivatives are D-2 dopamine agonists. 6-Oxo-1-substituted-octahydroquinolines and 6-oxo-1-substituted-decahydroquinolines which are additionally substituted in the 3- or 4-position are intermediates useful in preparation of the dopamine agonists. Acetals of 4,6-dioxo-1-substituted-decahydroquinoline 3-carboxylic acid esters enable synthesis of the foregoing compounds.