The monoterpene aldehydes (-)-myrtenal, (-)-perillaldehyde, and (+)-α-campholenic aldehyde were converted to nitriles by sequential
N,
N-dimethylhydrazonation, methylation, and an elimination reaction of the Hofmann-type. The nitriles were converted to terpenoyl chlorides by hydrolysis and chlorination with thionyl chloride. The chlorocarbonylated terpenes were condensed with pyrrolidine, 2-, 3-, or 4-methylpiperidines, and 2, 6- or 3, 5-dimethylpiperidines to obtain 21 terpene amides in 11_??_36% overall yields for the four steps starting from the imidation of the terpene aldehydes.
The bactericidal and fungicidal activities of these amides toward
Puccinia recondita R
OBERGE (wheat leaf rust),
Phytophthora infestans (M
ONT.) de B
ARY, and
Erysiphe graminis D. C. (f. sp.
tritici M
ARCHAL). 2, 6-Dimethyl-1-[2-(2, 2, 3-trimethyl-cyclopentyl-3-ene) acetoyl] piper idine at 300 ppm prevented the growth of
Puccinia recondita R
OBERGE in a pot test. When used to treat
Disbrotica longicornis S
AY,
Spodoptera frugiperda J. E. S
MITH, and
Tetranychus urticae K
OCH, 1-(6, 6-dimethylbicyclo-[3.1.1] hepto-2-ene-2-carbonyl)-2-methylpiperidine at 300 ppm almost completely eradicated
Disbrotica longicornis S
AY (corn rootworm) in soil treated with the amide. 1-(4-Isopropenyl-l-cyclohexene-l-carbonyl) pyrrolidine at 300 ppm inhibited the germination and growth of
Lycopersicon esculentum M
ILL. (tomato), but had no effect on
Echinochloa crus-galli B
EAUV.,
Setaria viridis B
EAUV.,
Tagetes sp.; and
Abutilon theophrasti M
ODIK. The other amides at the concentration of 300 ppm had little or no activity.
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