Stereochemistry Lecture 1 PDF

Pharmaceutical Organic Chemistry Hello  Hany Gamal Ezzat Lecturer of Pharmaceutical Organic Chemistry Hello Organic-III (PC306) Course Learning Outcomes (CLOs) 1-1-1-1. Outline the basic concepts of stereochemistry including isomer...

Pharmaceutical Organic Chemistry Hello  Hany Gamal Ezzat Lecturer of Pharmaceutical Organic Chemistry Hello Organic-III (PC306) Course Learning Outcomes (CLOs) 1-1-1-1. Outline the basic concepts of stereochemistry including isomerism, spatial and three-dimensional arrangement of organic compounds which may be used for preparation of some medicines. 2-2-1-2. Construct 3-D models of some organic compounds helping the identification of isomerism in organic compounds. 2-2-1-2. Solve stereo-chemical problems to differentiate between different isomers which may be used for preparation of some medicines. 4-1-1-2. Value time management skills. 4-1-2-3. Work effectively as part of a team and individually. Reference: - Organic chemistry, Paula Y. Bruice, 7th edition, 2016. 1 Hany Gamal Ezzat Organic-III (PC306) Stereochemistry ✓ Stereochemistry: Is also known as three-dimensional (3D) chemistry because the prefix "stereo-" means “three-dimensionality”. ✓ Stereochemistry: Study the arrangement of atoms in space in 3D structure and its effect on physical, chemical and biological properties. 2 Hany Gamal Ezzat Organic-III (PC306) Stereochemistry ✓ Drug in general, interacts with biomolecule structures (e.g. receptors and enzymes) in a very specific way to elicit a pharmacological response. ✓ Both drug and receptor possess specific complementary geometric shapes that fit exactly into one another. 3 Hany Gamal Ezzat Organic-III (PC306) Stereochemistry ✓ Drug in general, interacts with biomolecule structures (e.g. receptors and enzymes) in a very specific way to elicit a pharmacological response. ✓ Both drug and receptor possess specific complementary geometric shapes that fit exactly into one another. Agonist / Activator Antagonist / Blocker 4 Hany Gamal Ezzat Organic-III (PC306) Stereochemistry ✓ Isomers are NON identical (different) molecules that have the same molecular formula. ✓ The two major classes of isomers are Structural (constitutional) isomers and Stereoisomers. Identical NON-Isomers Structural (constitutional) Stereoisomers Same Molecular Formula Same Molecular Formula Different Connectivity Same Connectivity Different arrangement in space 5 Hany Gamal Ezzat Organic-III (PC306) Stereochemistry NON-Isomers M.F. = C2H6O Structural Isomers M.F. = C3H8O M.F. = C3H8O Stereoisomers M.F. = C3H8O Identical M.F. = C3H8O Structural Isomers M.F. = C3H8O 6 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Constitutional isomers (structural isomers): Isomers whose atoms have a different connectivity. Constitutional/structural isomers have ✓ different IUPAC names ✓ same or different functional groups ✓ different physical properties ✓ different chemical properties Constitutional Isomers 7 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: 1- Chain Isomers They are compounds that have the same molecular formula but differ in the carbon skeleton, and differ in their physical and chemical properties. C4H10 C5H12 8 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: 2- Metamers They are compounds that have same molecular formula but unequal distribution of carbon atoms on either side of the polyvalent functional group, and differ in their physical and chemical properties. C4H10O H H N N C4H11N N H Diethylamine Methyl propyl amine Methyl iso-propyl amine 9 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: 3- Positional Isomers They are compounds that have the same molecular formula but with different position of function group on carbon chain, and differ in their physical and chemical properties. C6H4Cl2 C5H12O 10 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: 4- Functional Isomers They are compounds that have the same molecular formula but with different function groups, and differ in their physical and chemical properties. C2H6O C 3H 6O 10 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: (a) (b) A & B: Structural Positional Isomers 11 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: (a) (b) A & B: Structural Metamers 12 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: (a) (b) (c) A & B: Structural Chain Isomers A & C: Structural Chain Isomers 13 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: A & B: Structural Functional Isomers A & C: Structural Chain Isomers 14 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: 1- Functional Isomers B&F D&E 2- Positional Isomers A&C 15 Hany Gamal Ezzat Organic-III (PC306) Structural (constitutional) Isomers Types of Constitutional Isomers: 5- Non Isomers 1- Chain Isomers 2- Metamers 3- Positional Isomers 4- Functional Isomers MATCH 5- Non Isomers 16 Hany Gamal Ezzat Organic-III (PC306) stereoisomers Stereoisomers (Interconvertible by rotation about single bond) Yes NO Conformational Configurational Alkanes , (rotate the plane of polarized light) NO Yes Cycloalkanes Geometrical Isomers Optical Isomers Alkynes Alkenes , Others Aromatic Cycloalkanes 17 Hany Gamal Ezzat Organic-III (PC306) Stereo-chemical representation There are four main types of representations for open-chain molecules and are used to show the two- or/three- dimensional structure of chemical compounds. 1-Perspective formula: When draw a perspective formula that the two bonds in the plane of the paper are adjacent to one another; neither the solid wedge nor the hatched wedge should be drawn between them. Perspective formula is usually use for molecules containing chiral center. Solid (in the plane) / solid wedge (in front of the plane) / solid hatched (behind the plane) 18 Hany Gamal Ezzat Organic-III (PC306) Stereo-chemical representation There are four main types of representations for open-chain molecules and are used to show the two- or/three- dimensional structure of chemical compounds. 2- Newman projection: Newman projection is used mainly for determining conformational relationships and to show interaction leading to steric hindrance between atoms or groups. 19 Hany Gamal Ezzat Organic-III (PC306) Stereo-chemical representation There are four main types of representations for open-chain molecules and are used to show the two- or/three- dimensional structure of chemical compounds. 3- Sawhorse projection: Carbon-carbon bond that is compressed in a Newman Projection is longer in a Sawhorse Projection Sawhorse Projections are very similar to Newman projections. Sawhorse structure is used to show interactions between groups on adjacent carbon atoms. 20 Hany Gamal Ezzat Organic-III (PC306) Stereo-chemical representation There are four main types of representations for open-chain molecules and are used to show the two- or/three- dimensional structure of chemical compounds. 4- Fischer Projection Formula: The horizontal bonds come forward, as solid wedges. The vertical bonds go back, as dashed lines. Fischer projections were originally proposed for the depiction of carbohydrates, and used for chiral compounds. 21 Hany Gamal Ezzat Organic-III (PC306) Stereo-chemical representation There are four main types of representations for open-chain molecules and are used to show the two- or/three- dimensional structure of chemical compounds. 22 Hany Gamal Ezzat Organic-III (PC306) final stretch  Summary Could you remember only three things about this lecture? (1)_____________ (2)_____________ (3)_____________ Almost done The End