Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(-)-myrtenol nitrate.
Efficient syntheses of climate relevant isoprene nitrates and (1R,5S)-(-)-myrtenol nitrate.
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DOI：
10.3762/bjoc.12.103
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发表时间：
2016
影响因子：
2.7
通讯作者：
Reeves CE
中科院分区：
文献类型：
--
作者：
Bew SP;Hiatt-Gipson GD;Mills GP;Reeves CE
在这里，我们报告了几种重要的、与气候相关的异戊二烯硝酸盐的化学选择性合成，使用硝酸银介导“卤化物取代硝酸盐”。采用容易获得的起始材料、试剂和Horner-Wadsworth-Emmons化学，使用便宜的“现成”材料合成了容易分离的、合成通用的“关键结构单元”（E）-和（Z）-3-甲基-4-氯丁-2-烯-1-醇以及（E）-和（Z）-1-（（2-甲基-4-溴丁-2-烯氧基）甲基）-4-甲氧基苯。利用它们的反应性，我们已经研究了它们进行“烯丙基卤化物对烯丙基硝酸酯”取代反应的能力，我们证明该取代反应以66-80%的总产率生成（E）-和（Z）-3-甲基-4-羟基丁-2-烯基硝酸酯，以及（E）-和（Z）-2-甲基-4-羟基丁-2-烯基硝酸酯（“异戊二烯硝酸酯”）。用NOESY实验阐明了纯化的异戊二烯硝酸酯中的碳-碳双键构型。进一步举例说明我们的“卤化物对硝酸盐”取代化学，我们概述了（1 R，2S）-（-）-桃金娘烯醇溴化物直接转化为以前未知的单萜硝酸盐（1 R，2S）-（-）-桃金娘烯醇硝酸盐。
Here we report the chemoselective synthesis of several important, climate relevant isoprene nitrates using silver nitrate to mediate a ’halide for nitrate’ substitution. Employing readily available starting materials, reagents and Horner–Wadsworth–Emmons chemistry the synthesis of easily separable, synthetically versatile ‘key building blocks’ (E)- and (Z)-3-methyl-4-chlorobut-2-en-1-ol as well as (E)- and (Z)-1-((2-methyl-4-bromobut-2-enyloxy)methyl)-4-methoxybenzene has been achieved using cheap, ’off the shelf’ materials. Exploiting their reactivity we have studied their ability to undergo an ‘allylic halide for allylic nitrate’ substitution reaction which we demonstrate generates (E)- and (Z)-3-methyl-4-hydroxybut-2-enyl nitrate, and (E)- and (Z)-2-methyl-4-hydroxybut-2-enyl nitrates (‘isoprene nitrates’) in 66–80% overall yields. Using NOESY experiments the elucidation of the carbon–carbon double bond configuration within the purified isoprene nitrates has been established. Further exemplifying our ‘halide for nitrate’ substitution chemistry we outline the straightforward transformation of (1R,2S)-(−)-myrtenol bromide into the previously unknown monoterpene nitrate (1R,2S)-(−)-myrtenol nitrate.