Ayako Kinoshita

Synthesis and Insecticidal Activity of Novel N-Oxydihydropyrrole Derivatives with a Substituted Spirocyclohexyl Group

A series of 5-spirocyclohexyl-3-(2,6-dimethylphenyl)-1,5-dihydro-2H-pyrrol-2-one derivatives (3) with various substituents on the spirocyclohexyl ring was synthesized and evaluated for its insecticidal activity against the aphid, Myzus persicae. Substituents at the 1- and 4-positions of the dihydropyrrole ring were also varied to optimize the activity. An investigation of the structure-activity relationship revealed that methoxy, alkoxyalkoxy, ethylenedioxy and methoxyimino groups were favorable as substituents at the 4-position of the spirocyclohexyl ring. The activity was optimized by the respective substitution of a methoxy or methoxymethoxy moiety and cyclopropylcarbonyloxy group at the 1- and 4-positions of the dihydropyrrole ring.

Synthesis and insecticidal activity of novel N-oxydihydropyrroles: 4-hydroxy-3-mesityl-1-methoxymethoxy derivatives with various substituents at the 5-position.

This paper reports the synthesis and insecticidal activity of a series of novel 4-hydroxy-3-mesityl-1-methoxymethoxy-1,5-dihydro-2H-pyrrol-2-one derivatives, in which the substituents at the 5-position were varied with a number of alkyl and spirocycloalkyl groups. Investigation of the structure-activity relationships revealed that small alkyl and spirocyclohexyl groups had a favorable effect on the insecticidal activity of these agents against Myzus persicae.

Synthesis and insecticidal activity of novel dihydropyrrole derivatives with N-sulfanyl, sulfinyl, and sulfonyl moieties.

This paper reports the synthesis and insecticidal activity of a new type of dihydropyrrole derivatives with sulfur moieties such as sulfanyl, sulfinyl, and sulfonyl groups at the 1-position. These derivatives exhibited high insecticidal potency against Nilaparvata lugens and Nephotettix cincticeps. Investigation of the structure-activity relationships revealed that the alkoxycarbonyloxy groups at the 4-position tended to increase the systemic insecticidal activity.

Synthesis and Insecticidal Activity of N-Oxydihydropyrroles: 4-Hydroxy-3-mesityl-5,5-dimethyl Derivatives with Various Substituents at the 1-Position

A new series of N-oxydihydropyrrole derivatives was synthesized and evaluated for insecticidal activity against Nilaparvata lugens and Myzus persicae. Various substituents were introduced to the 1-position of the dihydropyrrole ring, and the derivatives obtained exhibited systemic and/or contact insecticidal activity. The structure-activity relationship revealed that small alkyoxy and alkoxyalkoxy groups were more favorable than alkylcarbonyloxy, alkoxycarbonyloxy, or sulfonyloxy groups as substituents at the 1-position.

Synthesis of Milbemycins α9, α10, α11, α12, α14, α15, α20, α21, α22, α23, α26, α27, Δ2, 3, Δ4, 26-Milbemycins A3, A4 from Milbemycins

Chemical derivation methods to prepare 26-acyloxy and 26-hydroxymilbemycins, which had been reported as natural products, milbemycins alpha9, alpha10, alpha11, alpha12, alpha14, alpha15, alpha20, alpha21, alpha22, alpha23, alpha26, alpha27 from milbemycins A3, A4 were reported. Delta(2,3),delta(4,26)-milbemycins A3, A4, which had also been reported as natural products, were further prepared from milbemycins A3, A4. Their acaricidal activities were also assessed against the organophosphorus-sensitive two-spotted spider mite (Tetranychus urticae) on primary leaves of cowpea plants (Vigna sinesis Savi species) by spraying.

Synthesis of Milbemycins β9 and β10 from Milbemycins A3 and A4 and Their Biological Activities

Chemical derivation methods were used to prepare milbemycins β9 and β10 from milbemycins A3 and A4. Their acaricidal activities were also assessed against the organophosphorus-sensitive two-spotted spider mite (Tetranychus urticae) on primary leaves of cowpea plants (Vigna sinesis Savi species) by spraying.

Synthesis of 27-Oxo, 27-Hydroxymilbemycins A3 and A4 and Novel 27-Alkoxymilbemycins A3 and A4 from Milbemycins A3 and A4 and…

27-Oxomilbemycins A3 and A4 and 27-hydroxymilbemycins A3 and A4 were identified as metabolites in soil metabolism studies of milbemycins A3 and A4. Chemical derivation methods were developed to synthesize 27-oxomilbemycins A3 and A4 and 27-hydroxymilbemycins A3 and A4 from milbemycins A3 and A4. In addition, 27-alkoxymilbemycin derivatives were also synthesized from the same precursors. Some of the synthesized compounds displayed satisfactory acaricidal activity against the organophosphorus-sensitive two-spotted spider mite (Tetranychus urticae), but did not have superior activity to corresponding milbemycins A3 and A4.