有机立体化学chapter 1

1.3 History of Stereochemistry
Discovery of Plane-polarized Light
Isolation of the Ammonium Sodium Salts of (+)- and (-)-Tartaric Acid Hypothesis of Tetrahedral Carbon Structure
1.1 Importance of Stereochemistry
Material Sciences Life Sciences
Pharmacy
Stereochemistry
Fine Chemistry
Natural Products
Agrichemicals
1.1 Importance of Stereochemistry
CH3 O
H CH2 CH3
O
H3C
H CH2
H H 2C
CH3
(S)-carvone Caraway (coriander) seeds
(R)-carvone
spearmint
1.1 Importance of Stereochemistry
Enzymes are capable of distinguishing between enantiomers:
Biological importance (pheromone)
1.1 Importance of Stereochemistry
Agrichemical Importance
CH3 O
1.1 Importance of Stereochemistry
Important role in Fine Chemistry:C H3
Organic Stereochemistry
Yuxin Pei (裴玉新)
2013-09-02
Contents
1. 2. 3. 4. 5. 6. 7. 8. 9.
Introduction Stereoisomerism and Chirality Stereoisomer Discrimination Chirality in System lacking A Stereogenic Carbon Atom Stereoisomerism About Bonds of Restricted Rotation: cis-trans Isomerism Stereochemistry of Cyclic Compounds Nomenclature and Stereochemistry of Amino Acid and Some Simple carbohydrates Invited Lectures Lab Training : Resolution of (+/- )-Menthol
1. Introduction
1.1 Importance of Stereochemistry
1.2 Scope of Stereochemistry 1.3 History of Stereochemistry 1.4 Polarimetry and Optical Rotation
References: 1. Glossary (S1) 2. “Stereochemistry of Organic Compounds” by Eliel & Wilen : Page 1-8 (S2)
bigger the error. 3. Nonlinear affected by concentration, temperature, impurity, solvent and etc.. 4. Large amount of sample needed.
1.4 Polarimetry and Optical Rotation
1.3 History of Stereochemistry
1.3 History of Stereochemistry
/ChemHistory/Van't-Hoff-1874.html
1.3 History of Stereochemistry
1.4 Polarimetry and Optical Rotation
optical activity
1.4 Polarimetry and Optical Rotation
optical activity
1.4 Polarimetry and Optical Rotation
Polarimeter
eg.3
O
O NH
(R)
H+
O HN O
(S)
O
O
O
(R)-Thalidomide Sedative and hypnotic
O
( S)-Thalidomide Teratogen
1.1 Importance of Stereochemistry
eg.4
1.1 Importance of Stereochemistry
eg.1
1.1 Importance of Stereochemistry
eg.2
1.2 Scope of Stereochemistry Stereochemistry
Static/molecules
Dynamic/reactions
Stereochemical requirements Counting of stereoisomers Molecular architecture, energy Stereochemical outcome of reactions, including interconversion of Physical properties conformational isomers or topomers Spectral properties Deeply related with study and understanding of reaction mechanism
Pharmaceutical Importance
stereochemistry: The properties of many medicines depend on their
HN HN O O O O CH NH NHCH3CH3 CH3NH 3NH
eg.1
Cl Cl
(S)L. Gay-Lussac
1.3 History of Stereochemistry
L. Pasteur and J. Baptiste-Biot
1.3 History of Stereochemistry
Crystal of Ammonium sodium tartrate
Chirality: A term that describes the “handedness” of a molecule.
A chiral molecule: - not superposable on its mirror image; - has optical activity (the property of rotating the plane of plane-polarized light).
Problem:
Please explain the meaning of the following description: = -20.6° (c 1.3, CHCl3)
Chapter 1 Homework
1. a) b) c) d) e) f) g) 2. 3. Explain briefly the meaning of the following basic stereochemical terms. Stereochemistry Chirality Plane-polarized light Polarimeter Optical activity Observed optical rotation Specific rotation What is the units of observed optical rotation and specific rotation? Design an experiment for measuring the specific rotation of a chiral compound. Specify the factors which should be considered.
Counter-clockwise direction (-) or (l)
1.4 Polarimetry and Optical Rotation
specific rotation (D = sodium lamp, λ = 589 nm).
α: Observed rotation
c： Concentration（g/100mL） l：
Length （dm）
= +6.2° (c 1.0, EtOH)
1.4 Polarimetry and Optical Rotation
Limitation:
1. [α]max unknown in most cases, questions regarding reliability of the published data. 2. The smaller the optical rotation, the
1.3 History of Stereochemistry
*
* Discovered by Malus, French physicist in 1809.
1.3 History of Stereochemistry
1.3 History of Stereochemistry
1.3 History of Stereochemistry