缬氨酸杀虫菊酯的合成

The Synthesis of Valine  containing Pyrethrin

缬氨酸杀虫菊酯是一类很有发展前景的杀虫杀螨剂，它的菊酸部分为Ｒ－构型，菊醇部分为Ｓ－构型，其合成是由相应的缬氨酸或者它的活性衍生物与相应的醇经酯化而制得。具体过程是Ｄ－缬氨酸经６ＮＨＢｒ／ＮａＮＯ２溴化制成（Ｒ）－α－溴代异戊酸，再与对三氟甲基苯胺反应合成（Ｒ）－Ｎ－［（４－三氟甲基）苯基］α－缬氨酸，后被Ｎ－氯代琥珀酰亚胺氯化制成（Ｒ）－Ｎ－［２－氯－４－（三氟甲基）苯基］α－缬氨酸，最后与（Ｓ）－α－氰基－３－苯氧苯基甲醇用ＤＣＣ脱水酯化合成缬氨酸杀虫菊酯Ｉ（Ｒ１＝Ｆ３Ｃ，Ｒ２＝Ｈ，ＣＬ，Ｒ３＝Ｈ）。还给出了两种菊酯２×４种异构体杀虫（烟草夜蛾和家蝇）活性数据。

Valine derivatives(derirs). I in which the acid has the R configuration and the alcohol (alc.) has the S configuration,were prepared by esterifying the corresponding valines or their active derivs.with appropriate alcs.Thus,(R)valine were treated with 6N HBr/NaNO_2 to give (R)Me_2CH CHBr CO_2H,which were treated with p(F_3C)C_6H_4NH_2 to give (R)p(F_3C)C_6H_4NHCH(CHMe_2) CO_2H,which were chlorinated by Nchlorosuccinimide to give(R)_2CL_4(F_3C)C_6H_4NHCH(CHMe_2) COOH,which were esterifid with(s)-α-cyano-3-phenxybenzy alc. by DCC to give (Racid,Salc.)I. The pesticidal activities of the 4 diastereomers of I(R1=F_3C,R_2=H,Cl,R_3=H) were determined against Heliothis virescens and Musca domestica.