New reactions and step economy: the total synthesis of (±)-salsolene oxide based on the type II transition metal-catalyzed intramolecular [4+4] cycloaddition
作者:Paul A. Wender、Mitchell P. Croatt、Bernhard Witulski
DOI:10.1016/j.tet.2006.02.085
日期:2006.8
of the type II nickel-catalyzed intramolecular [4+4] cycloaddition of bis-dienes show that it is influenced by both diene substitution and geometry. Both E- and Z-isomers of 19 and 20 react, albeit at markedly different rates, to afford cycloadducts, whereas only the Z-isomer of 9 (and not the E-isomer) reacts to give 8 and 25. Chemoselective elaboration of 8 to (±)-salsolene oxide (7) was used to confirm
II型镍催化的双二烯分子内[4 + 4]环加成反应的可行性研究表明,它受二烯取代和几何形状的影响。既ë -和ž的异构体19和20进行反应,尽管显着不同的速率,以得到cycloadducts,而只有Ž -异构体9(而不是ë发生反应异构体),得到8和25。化学合成的8到(±)-氧化丁二烯砜(7)用于确定环加合物的结构,同时建立了一步一步的经济途径生产天然产物的方法。