PRELIM 03 - Stereochemistry Flashcards
Refers to the three-dimensional orientation of the functional groups present in a molecule
Sterochemistry
__________ are molecules that contain the same number and kinds of atoms, the same arrangement of bonds, but different three-dimensional structures
Stereoisomers
2 types of stereoisomers (ED)
Enantiomers, Diastereomers
Are pairs of molecules for which the three-dimensional arrangement of atoms represents nonsuperimposable mirror images (Types of stereoisomers)
Enantiomers
Represents all of the other stereoisomeric compounds that are not enantiomers (Types of stereoisomers)
Diastereomers
__________ includes compounds that contain double bonds and ring systems (Types of stereoisomers)
Diastereomers
Exhibit different physicochemical properties, including melting point, boiling point, solubility, and chromatographic behavior (Types of stereoisomers)
Diastereomers
Rotates the plane of polarized light to the right, or in a clockwise direction; indicated by a (+) sign
Dextrorotatory
Rotates the plane of polarized light to the left, or in a counterclockwise direction; indicated by a (-) sign
Levorotatory
Dextroamphetamine, dextromethorphan, and dexlansoprazole are all __________
Dextrorotatory
Levodopa, levothyroxine, and levofloxacin are all __________
Levorotatory
Most sugars found in nature (ex: D-glyceraldehyde, D-glucose) are __________
Dextrorotatory
Most amino acids found in nature (ex: L-serine, L-alanine) are __________
Levorotatory
A mixture comprised of equal amounts (1:1 mixture) of both of the possible drug enantiomers; indicated by the placement of a (±) sign before the compound name
Racemic mixture (Racemate)
A new system of stereochemical nomenclature; uses the R-S and cis-trans configuration
Cahn-Ingold-Prelog (CIP) system
Priority sequence proceeds to the right, or in a clockwise direction (Configuration in CIP system)
R-configuration
Priority sequence proceeds to the left, or in a counterclockwise direction (Configuration in CIP system)
S-configuration
Inactive configuration of ibuprofen
R-ibuprofen
Active configuration of ibuprofen; possesses anti-inflammatory effect
S-ibuprofen
The R-enantiomer of Modafinil (a racemic mixture)
Armodafinil
The S-enantiomer of Omeprazole (a racemic mixture)
Esomeprazole
When two substituents of higher priority are on the same size of the double bond (Configuration in CIP system)
Cis (Z-isomer)
When two substituents of higher priority are on the opposite sides of the double bond (Configuration in CIP system)
Trans (E-isomer)
__________-diethylstilbestrol is estrogenic, whereas cis-diethylstilbestrol is only 7% as active
Trans
Trans-diethylstilbestrol is estrogenic, whereas __________-diethylstilbestrol is only 7% as active
Cis
Inactive configuration of triprolidine
Z-triprolidine
Active configuration of triprolidine
E-triprolidine
____________ refers to a preference for one stereoisomer as a substrate for a metabolizing enzyme; may lead to differences in metabolism for the two enantiomers
Substrate stereoselectivity
(+) enantiomer of __________ undergoes more rapid metabolism than the corresponding (-) enantiomer; this is an example of substrate stereoselectivity
Propranolol
__________ refers to the preferential metabolic formation of a stereoisomeric product
Product selectivity
In humans, __________ is metabolized predominantly to the trans alcohol, whereas rats primarily tend to form the cis alcohol; this is an example of product selectivity
Pentazocin
__________ refers to the selective metabolism of two or more similar functional groups that are positioned in different regions of a molecule
Regioselectivity
Of the four methoxy groups present in __________, the 4-OCH3 group is regioselectively O-demethylated in several species; this is an example of regioselectivity
Papaverine
Active configuration of epinephrine
R-epinephrine
