保幼激素类似物11-甲氧基-3,7,11-三甲基-2,4-十二碳二烯酸异丙酯的简便全合成

从价廉的丙酮出发,首先经羟醛缩合、脱水、氧化、酯化、溴代反应合成了4-溴-3-甲基-2-丁烯酸异丙酯,继而与亚磷酸三乙酯反应得到了Wittig-Homer试剂,随后与香茅醛发生Wittig-Horner反应,最后在阳离子树脂催化作用下与甲醇醚化,成功地全合成了具有保幼激素活性的昆虫生长调节剂11-甲氧基-3,7,11-三甲基-2,4-十二碳二烯酸异丙酯.所得标题化合物的四种异构体中,具有较高生物活性的(2E,4E)-异构体的含量达66%.各步所合成化合物的结构经1H NMR,IR,MS分析确证.

Simple Total Synthesis of Juvenile Hormone Analogue--Isopropyl 11- Methoxy - 3,7,11 - trimethyl - 2,4 - dodecadienoate

Isopropyl 4 bromo 3 methyl 2 butenoate was prepared from initial acetone via condensation, dehydrolysis, oxidation, esterification and bromination. Then, reaction of the synthesized isopropyl 4 bromo 3 methyl 2 butenoate with triethyl phosphite provided Wittig Horner reagent. Subsequently, Wittig Horner reaction of the Wittig Horner reagent with citronellal was carried out, and followed by the etherification with methanol catalyzed by cation exchange resin, to finally give isopropyl 11 methoxy 3,7,11 trimethyl 2,4 dodecadienoate with juvenile hormone activity. The 2 E ,4 E stereoisomer (over 66% yield) showed considerably higher activity than other isomers. The structures of all the compounds were confirmed by 1H NMR, IR and MS spectra.