Asymmetric Synthesis of Sesaminone: Confirmation of Its Structure and Determination of Its Absolute Configuration
作者:Andrew T. Maioli、Rita L. Civiello、Bruce M. Foxman、Dana M. Gordon
DOI:10.1021/jo971027c
日期:1997.10.1
absolute configuration of L-Phe. The opening of the synthesis was a diastereoselective Evans aldol reaction between N-4-pentenoyloxazolidinone 6 and piperonal. Reduction of the major diastereomer of the aldol product provided enantiomerically pure diol 4. The primary and secondary hydroxyl groups of 4 were protected in tandem to generate silyl ether-MOM ether 9. The vinyl group contained in 9 was then elaborated
已经实现了天然存在的四氢呋喃木脂素芝麻素((-)-1)对映体的不对称合成。合成材料的X射线晶体结构验证了该木脂素在文献中提出的结构。另外,通过合成四氢呋喃与已知的L-Phe的绝对构型的相关性来建立天然产物的绝对构型。合成的开始是N-4-戊烯基恶唑烷二酮6与胡椒醛之间的非对映选择性Evans羟醛反应。醛醇产物的主要非对映异构体的还原提供了对映体纯的二醇4。4的伯羟基和仲羟基被串联保护以生成甲硅烷基醚-MOM醚9。然后,通过一系列的四步,得到芳基酮10。将该芳基酮转化成甲硅烷基烯醇醚立体异构体(11a,b)的混合物;TiCl(4)介导的烯醇醚混合物中所含MOM醚的活化产生四氢呋喃12作为主要产物。用氟化物处理12提供合成的(-)-1。