Two approaches to the strigolactone tricyclic lactone skeleton 2 were investigated using ketene/ketene-iminium cycloaddition to olefins. Finally, the first enantioselective access to the four stereoisomers of 5-deoxystrigol 1 is reported using an intramolecular [2+2] cycloaddition of homochiral ketene-iminium salts 5. Very high asymmetric control was achieved with C-2 symmetric pyrrolidines as chiral
使用烯酮/烯酮-
亚胺基环加成到烯烃中,研究了两种方法制备
异烟酸酯内酯
三环内酯骨架2。最后,报道了使用同手性烯酮-
亚胺盐5的分子内[2 + 2]环加成反应,首次对5-脱氧
雌三醇1的四个立体异构体进行对映选择性访问。使用C-2对称
吡咯烷作为手性助剂,可以实现非常高的不对称控制。