NEW MATERIAL: A compound of 6- and/or 7-oxo-trans-1,2,3,4,4a,5,10,10a- octahydro-benzo[g]quinoline in which the 3-position is substituted with COOH which can be amidated, CH 2 OH which can be etherified, CH 2 CN, alkyl or aryl thiomethyl, NHSO 2 NH 2 or NHCONH 2 or free type or salt of its ester which is hydrolyzed physiologically and physiologically allowable.
EXAMPLE: 3β-Methoxycarbonyl-6-methoxy-1,2,3,4,4aα,5,10,10aαβ-octahydro- benzo[g]quinoline (racemic compound).
USE: Prolactin secretion controlling agent.
PROCESS: A compound of formula I (rings A and B are trans-bonded; X is benzyl or 1-4C alkyl; R' 1 , and R' 2 are each OCH 3 , one of them can be H; R' 4 is esterified COOH, etc.) is cleaved to eliminate OX to obtain a compound of formula II.