One of the photocycloadducts obtained during methyl 2,4-dioxopentanoate to isoprene was converted to optically active iridoids. Using a CrCl2 reductive-coupling reaction, proper combinations of two kinds of enantiomeric iridoids, 1-iriden-7-al and 9-benzyloxy-7-chloro-1-iridene, produced versatile intermediates for various types of 5-8-5-membered tricyclic natural products. From one such product, fusicocca-2,8,10(14)-triene (1) was synthesized by sequential transformations.
2,4-二氧代
戊酸甲酯生成
异戊二烯过程中获得的光环加合物之一被转化为光学活性环烯醚萜。利用CrCl2还原偶联反应,将两种对映体环烯醚萜化合物1-iriden-7-al和9-benzyloxy-7-
氯-1-iridene适当组合,产生了各种类型5-8-5-的多功能中间体。元
三环天然产物。通过连续转化,从这样的一种产物中合成了 fusicocca-2,8,10(14)-triene (1)。