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PHC 211 Stereochemistry LEC. 6 Tues, 1/11/1433 H Dr. Maha Al-Mutairi. Lecture contents:. Significance of Chirality More Than One Chiral Carbon Meso Compounds Revision. Lecture outcomes. By the end of this lecture, students able to:
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PHC 211 Stereochemistry LEC. 6 Tues, 1/11/1433 H Dr. Maha Al-Mutairi
Lecture contents: • Significance of Chirality • More Than One Chiral Carbon • Meso Compounds • Revision
Lecture outcomes By the end of this lecture, students able to: • Identify and calculate no. of isomers for compounds with more than one chiral carbon. • Recognize and state the characteristics of meso compounds.
What is the Significance of Chirality in the Biological World?
More Than One Chiral Carbon Two chiral carbon: • Each of these tow chiral carbons can be either (R) or (S). • The maximum number of optical isomers for a compound is 2n, where n is the number of chiral atoms.
Cont.More than one chiral carbon Q: How many stereoisomers could exist for a compound has three different chiral carbon?
Cont.More than one chiral carbon (R) And (S) system for a compound with two chiral carbon atoms: • EXAMPLES: • 1,2-Dibromo-1-phenylpropane • 2,3,4-trihydroxybutanal (erthyrose)
Cont.More than one chiral carbon Enantiomers and diastereomers: 2-Bromo-3-chlorobutane
Meso compounds • In the simplest case, they are compounds which have internal plan of symmetry. • EXAMPLE: • Tartaric acid
Cont. Meso compounds • Important properties of meso compounds with 2 chiral centers: • They are optically inactive. • They must be (R,S) configuration. • They are diastereomers of the (R,R) and (S,S) isomer.