高等有机化学-结构与光学活性1.ppt

Advanced Organic Chemistry(1)高等有机化学（I） Instructor: JingKui YANG 杨镜奎 College of Chemistry and Chemical Engineering Graduate University of CAS (GUCAS) 问题解答: 二等份型与酮的构象 1-Butene? Eclipsed(重叠) more stable than bisected(二等分型) and C is more stable than d by 0.15 Kcal/mol  Cram Principle 1 Chapt 3 Stereochemistry (立体化学) Introduction: History and Opticity (旋光) Conformation(构象) Chiral molecules(手性分子) and Enantiomers(对映异构体) Configuration(构型) Constitutional(结构:链,位置,官能团) Stereoisomers (立体)Isomers(顺反,对映,构象: 消旋) Structure Optical Activity(结构与光学活性) Stereochem. and Org Synthesis(立体化学与合成) Application of Spectra in Stereochem. (光谱: NMR, IR, UV, ORD/CD 在立体化学中的应用) Isolation of isomers(异构体的分离) Chapt 3.3 Chirality(手性)/Configuration (构型)/ Enantiomers 对映异构体 Chirality Chiral carbon( asymmetric carbon atom) : 4 different substitutes attached (stereo or structures) to one Carbon atoms 一个碳原子与 4 个不同基团连接(结构或立体不同) Dissymmetric (非对称性)Molecule: 分子与镜像不重叠 为旋光性的必要条件 Achiral molecules(非手性分子/对称分子) σ, I, Sn Asymmertic molecules(非对称分子) Cn Non Asymmetric Molecule(不对称分子) no any of σ, I, Sn, Cn(无任何对称性) Cyclobutane? Not planar - reduced eclipsing interactions Relative and Absolute Configuration(相对和绝对构型) 1951 later X-Rays: measure the Absolute Configuration of compounds Obtained from the-Glyceraldehyde (甘油醛) - Relative configuration D ,L Problem Standard materials must be used, but one compound can lead to different configuration product via different way (同一化合物变成不同D or L 型通过不同反应途径) So R/S nomenclature used 1956, Cahn, Ingold, Prelog 提出 R: Rectus (右) S: Sinister(左) R、S标记法：由大到小，按次序规则。 I Br Cl SO2R SOR SR SH F OCOR OR OH NO2 (多)手性中心化合物 Raceme: 外消旋体: 二个等量的对映体化合 物形成的混合物. Meso(内消旋) : 分子内有对称面可以抵消手性中心的旋光性的单分子化合物(inactive, i) Diastereomers( 非对映异构体)镜像不能重叠的不同化合物异构体Epimer(Epimeride) (差向异构体)只有一个手性碳原子的构型相反的多手性中心化合物异构体 Difference Between Configuration  Conformati