An operationally simple TiII-mediated, stereo- and regio-specific reduction of isolated, conjugated and methylene ‘skipped’ polyynes to the corresponding Z-polyenes in a one-pot procedure is described and applied inter alia to the syntheses of deuterium labelled linolenic and oleic acids. Final quenching with D2O (instead of H2O) results in regio- and stereo-specific Z-dideuteration of the alkyne. The synthesis of (3E,8Z,11Z)-tetradeca-3,8,11-trienyl acetate, the major sex pheromone of Scrobipalpuloides absoluta, a destructive pest of tomatoes, and the (3Z,8Z,11Z)-isomer, utilises this methodology in key reduction steps, and under- or over-reduction are negligible.
本文描述了一种操作简便的TiII介导的一锅法立体和区域选择性还原孤立共轭亚甲基跳跃多
炔烃至相应的Z-多烯烃的方法,并应用于
氘标记
亚麻酸和
油酸的合成。最终用D2O(而非
H2O)淬灭反应,实现了
炔烃的区域和立体选择性双
氘化。(3E,8Z,11Z)-十四碳-3,8,11-
三烯基
乙酸酯(主要性信息素)和(3Z,8Z,11Z)异构体的合成,利用了这种方法在关键还原步骤中,且不足或过度还原的情况可忽略不计。