Enantioselective and diastereoselective hydroxylation of bufuralol. Absolute configuration of the 7-(1-hydroxyethyl)-2-[1-hydroxy-2-(tert-butylamino)ethyl]benzofurans, the benzylic hydroxylation metabolites
作者:S. Ananda Weerawarna、Stefan M. Geisshusler、Satya S. Murthy、Wendel L. Nelson
DOI:10.1021/jm00114a019
日期:1991.10
diastereomers with the 1"R absolute stereochemistry at the new chiral center in products from (1'R)-1 by a ratio of 4.5:1 [(1'R,1"R)-2:(1'R,1"S)-2] and by nearly 8:1 [(1'S,1"R)-2:(1'S,1"S)-2] from (1'S)-1. (1'R)-Bufuralol was more rapidly hydroxylated than was (1'S)-1, by about 3-fold. In the presence of human liver microsomes, (1'R)-bufuralol was also more rapidly hydroxylated than was (1'S)-1, by ca. 2.5-fold
描述了非对映体7-(1-羟乙基)-2- [1-羟基-2-(叔丁基氨基)乙基]苯并呋喃(2),丁富洛尔(1)的苄基羟基化代谢产物的合成以及分配了这些非对映异构体的构型。用(2S)-(-)-2-氨基-3-甲基-1,1-二苯基丁烷-1-醇和硼烷的复合物还原1“-氧杂富乐酚(3),得到2,其95:5通过HPLC测定可能的1“ R和1” S异构体的比率。通过异氰酸1-苯乙酯的对映异构体(PEIC)的衍生化作用,便于分离所得非对映异构体。绝对构型1'S,1“ R和1'R将1“ R分配给过量形成的非对映异构体2c和2b,通过使用该手性硼烷试剂将紧密相关的烷基苯基酮还原为R醇的已知立体化学为基础。四种异构苄醇的圆二色性光谱与这些赋值一致。在存在大鼠肝微粒体部分的情况下,丁草胺的苄基羟基化反应明显地有利于立体异构的产物立体选择性形成非对映异构体,在(1'R)-1的新手性中心的新手性中心具有1“ R绝对立体化学,比率为4