Gromova Marya A, Kharitonov Yurii V, Bagryanskaya Irina Yu, Shults Elvira E
Novosibirsk Institute of Organic Chemistry SB RAS Lavrentjev Avenue 9 630090 Novosibirsk Russia.
Department of Physical Chemistry Novosibirsk Institute of Organic Chemistry SB RAS Lavrentjev Avenue 9 630090 Novosibirsk Russia.
ChemistryOpen. 2018 Nov 14;7(11):890-901. doi: 10.1002/open.201800205. eCollection 2018 Nov.
The -(2,3-butadienyl)carboxamide of isopimaric acid, that is, compound , was prepared through a two-step synthetic procedure starting from the natural diterpene isopimaric acid. The Pd-catalyzed cross-coupling and subsequent cyclization of terpenoid allene with several aryl iodides and aryl bromides gave access to optically active diterpenoid-oxazoline derivatives in good to excellent yields. The functional group tolerance in the aryl iodides was demonstrated by several examples, including substrates with additional --butoxycarbonyl-protected amino, hydroxy, and carboxy substituents in the position. The cross-coupling-cyclization reaction of those compounds with allene proceeded selectively with the formation of cyclization products on the substituent in the aromatic ring. This transformation opens a potential route to the synthesis of hybrid compounds containing a tricyclic diterpenoid and several heterocycles.
异海松酸的-(2,3-丁二烯基)甲酰胺，即化合物 ，是从天然二萜异海松酸开始通过两步合成程序制备的。萜类丙二烯 与几种芳基碘化物和芳基溴化物的钯催化交叉偶联及随后的环化反应，以良好至优异的产率得到了光学活性的二萜-恶唑啉衍生物。通过几个例子证明了芳基碘化物中的官能团耐受性，包括在 位带有额外的叔丁氧羰基保护的氨基、羟基和羧基取代基的底物。这些化合物与丙二烯 的交叉偶联-环化反应选择性地进行，在芳环上的取代基上形成环化产物。这种转化为合成含有三环二萜和几个杂环的杂化化合物开辟了一条潜在途径。
