作者:Marcus Eh
DOI:10.1055/s-2003-37345
日期:——
The synthesis of 3-methyl-1,4-dioxacylopentadecan-2-one (12c) and 3-methyl-1,4-dioxacylohexadecan-2-one (12d), two new musk odorants, is described starting from methyl 2-bromopropionic acid (6b) and allylic alcohol, respectively. The key step of the synthesis is the ring-closing olefin metathesis (RCM) to the unsaturated 1,4-dioxamacrolides. Insight into the structure-odor relationship (SOR) is provided by the synthesis of ten related unsubstituted or methyl substituted oxamacrolides. Finally, a four step enantioselective synthesis of both (3R)-(+)- and (3S)-(-)-3-methyl-1,4-dioxacyclopentadecan-2-one as well as (3R)-(+)- and (3S)-(-)-3-methyl-1,4-dioxacyclohexadecan-2-one reveals that mainly the (3R)-(+) enantiomers are responsible for the powerful musky odor characteristic. Their synthesis starts from ethyl (2S)-2-hydroxypropanoate (14) or isobutyl (2R)-2-hydroxypropanoate (15) which were treated under acidic conditions with allyl trichloroacetimidate (16), followed by titanate mediated transesterification, ring-closing olefin metathesis and hydrogenation.
本文介绍了分别从 2-溴丙酸甲酯(6b)和烯丙基醇开始,合成 3-甲基-1,4-二氧杂环戊烷-2-酮(12c)和 3-甲基-1,4-二氧杂环十六烷-2-酮(12d)这两种新型麝香气味剂。合成的关键步骤是通过闭环烯烃偏析(RCM)生成不饱和的 1,4-二氧杂环戊烷。 通过合成十种相关的未取代或甲基取代的氧杂二茂酰胺,深入了解了结构-气味关系(SOR)。最后,对 (3R)-(+)- 和 (3S)-(-)-3- 甲基-1,4-二氧杂环十五烷-2-酮以及 (3R)-(+)- 和 (3S)-(-)-3- 甲基-1,4-二氧杂环十六烷-2-酮进行了四步对映体选择性合成,结果表明主要是 (3R)-(+) 对映异构体产生了强烈的麝香气味特征。 它们的合成始于(2S)-2-羟基丙酸乙酯(14)或(2R)-2-羟基丙酸异丁酯(15),在酸性条件下用三氯乙酰亚氨烯丙基酯(16)处理,然后进行钛酸酯介导的酯交换反应、闭环烯烃偏聚反应和氢化反应。