A chiral pool approach for asymmetric syntheses of both antipodes of equol and sativan
作者:Chinni Yalamanchili、Amar G. Chittiboyina、Sateesh Chandra Kumar Rotte、John A. Katzenellenbogen、William G. Helferich、Ikhlas A. Khan
DOI:10.1016/j.tet.2018.03.004
日期:2018.4
followed by intramolecular Mitsunobu reaction and deprotection steps resulted the target compounds, S-(−)-equol and S-(+)-sativan, with high degree of enantiopurity. By simply switching the chiral auxiliary to (S)-4-benzyloxazolidin-2-one and following the same synthetic sequence the antipodes, R-(+)-equol and R-(−)-sativan were achieved. Both enantiomers are of interest from a clinical and pharmacological
首次从易得的原料开始,以> 98%ee合成异黄烷酮,雌马酚和sativan的对映体。手性异黄酮(-)-雌马酚是由大豆异黄酮,formonentin和黄豆苷元通过肠道细菌在某些人群中的作用而产生的,据报道,其他手性异黄烷也来自各种植物化学来源。为了生产克量的这些手性异黄烷醇,将埃文斯的对映选择性羟醛缩合用作手性诱导步骤,以在C-3位置引入所需的手性。将手性硼烯酸酯加到取代的苯甲醛中导致官能化的合成-羟醛产品,产率> 90%,非对映选择性优异。官能团转化,随后进行分子内光延反应和脱保护步骤,得到具有高对映体纯度的目标化合物S -(-)-雌马酚和S -(+)-sativan。通过简单地将手性助剂切换为(S)-4-苄基恶唑烷丁-2-酮,并按照相同的合成顺序,对映体R -(+)-雌马酚和R-(-)-满足。从临床和药理学观点来看,这两种对映异构体都是令人感兴趣的,并且目前正在被开发为营养药物和药理学试