Synthesis of optically active 5,6,7,8‐tetrahydroquinolines

(+)‐( R )‐5‐Methyl‐ and (+)‐( R )‐2,5‐dimethyl‐8‐isopropylidene‐5,6‐dihydro‐7 H ‐quinoline, 7 and 11 , were synthesized by reaction of ( R )‐pulegon morpholino‐enamine with acrolein or methyl vinyl ketone. The Michael adducts thus formed were reacted with hydroxylammonium hydrochloride in polar media. Compound 7 was also obtained by thermal rearrangement of the O ‐allyl ether of pulegone oxime. The selectivity of both synthetic methods were rather poor (30–49%). Isolation of 7 and 11 in the pure state was accomplished by preparative glc.