Synthesis of Enantiopure Homoallylic Ethers by Reagent Controlled Facial Selective Allylation of Chiral Ketones
作者:Lutz F. Tietze、Berthold Weigand、Ludwig Völkel、Christian Wulff、Christian Bittner
DOI:10.1002/1521-3765(20010105)7:1<161::aid-chem161>3.0.co;2-9
日期:2001.1.5
The stereoselective allylation of chiral methyl ketones to give tertiary homoallylic ethers, which can easily be transformed into homoallylic alcohols, is described. Reaction of the enantiopure ketones 8a-d and the racemic ketones 26a-d with the norpseudoephedrine derivative 2 or ent-2 and allylsilane in the presence of a catalytic amount of trifluoromethanesulfonic acid, led to a series of homoallylic
描述了手性甲基酮的立体选择性烯丙基化以产生叔均烯丙基醚,其可容易地转化成均烯丙基醇。对映纯酮8a-d和消旋酮26a-d与正伪麻黄碱衍生物2或ent-2和烯丙基硅烷在催化量的三氟甲磺酸存在下反应,生成了一系列均聚醚,具有良好或优异的非对映选择性( 85:15至> 97:3)。烯丙基化是试剂控制的,并且几乎独立于底物中的立体异构中心。使用外消旋酮26a-d观察到部分动力学拆分。在手性酮8a-d与非手性试剂乙氧基三甲基硅烷和烯丙基硅烷的反应中,仅观察到低的非对映选择性。