Tietze L F, Weigand B, Völkel L, Wulff C, Bittner C
Institut für Organische Chemie, Georg-August-Universität Göttingen, Germany.
Chemistry. 2001 Jan 5;7(1):161-8. doi: 10.1002/1521-3765(20010105)7:1<161::aid-chem161>3.0.co;2-9.
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 ethers with good to excellent diastereoselectivity (85:15 to > 97:3). The allylation is reagent controlled and nearly independent from the stereogenic centers in the substrates. A partial kinetic resolution was observed using the racemic ketones 26a-d. In the reaction of the chiral ketones 8a-d with the achiral reagents ethoxytrimethylsilane and allylsilane only a low diastereoselectivity was observed.
本文描述了手性甲基酮的立体选择性烯丙基化反应，生成叔高烯丙基醚，该醚可轻松转化为高烯丙基醇。对映体纯的酮8a - d和外消旋酮26a - d与降麻黄碱衍生物2或对映体- 2以及烯丙基硅烷在催化量的三氟甲磺酸存在下反应，得到了一系列具有良好至优异非对映选择性（85:15至>97:3）的高烯丙基醚。烯丙基化反应受试剂控制，且几乎与底物中的立体中心无关。使用外消旋酮26a - d时观察到了部分动力学拆分。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，仅观察到较低的非对映选择性。
