作者:Dale E. Ward、Jianheng Shen
DOI:10.1021/ol070994z
日期:2007.7.1
The total synthesis of (-)-cyathin A3 is described. The key step involves an unusual enantioselective Diels-Alder reaction of 2,5-dimethyl-1,4-benzoquinone with 2,4-bis(trimethylsilyloxy)-1,3-pentadiene, using Mikami's catalyst [(R)-BINOL + Cl2Ti(OiPr)2 + 4 A mol sieves] modified by addition of Mg and SiO2. Because cyathin A3 is easily transformed into allocyathin B3, cyathin B3, cyathin C3, and neoallocyathin
描述了(-)-胱氨酸A3的总合成。关键步骤涉及使用Mikami的催化剂[(R)-BINOL + Cl2Ti)使2,5-二甲基-1,4-苯醌与2,4-双(三甲基甲硅烷氧基)-1,3-戊二烯发生不寻常的对映选择性Diels-Alder反应[OiPr)2 + 4 A摩尔筛]通过添加Mg和SiO2进行改性。因为组织蛋白酶A3很容易转化为allocyathin B3,cyathin B3,cyathin C3和neoallocyathin A4,所以这种途径也构成了这些天然产物的正式合成。