Question

Indicate the stereochemical configuration for the tetrahedral centers shown below. OR OS not a configuration center Br R OS not a configuration center ООО

Answer 1

Sol: Hd (*) Tetrahedral carbon center. According to CIP rule: Priority orders: a) b) c) d lowest priority group below the plane - Anti clockwise rotation (s- configuration) > is configuration. u Br (a) = Tetrahedral carbon center (d) H D Il rotation According to cIP rule: Priority onder: - By) -(1) - CH₂ CH3>H i.e a) b) c) d lowest priority group above the plane - Anti clockwise rotation = 'R' configuration. © (R- configuration) H & & Ez chinal centens H. A el - chiral centen: For, © ( It fo (R-configuration)

According to CIP Rule: Priority onder: a) b) ed Lowest prionity group above the plane Anti clockwice rotation - R- configurature. For. &-chinal centers R! V rotation s- configuration Acconding to CIP Rule! Priority order: a> b) c) d Lowest priority group above the plane clockwise rotation s- configuration. for the above Hence, The TUPAL comp ound is (2R, 35)-2-chloro-3-methylpentane. Da name H 1 H 180° H H el rotation in plane e structure -I structure- I & B are superimposable if one is notated by 180° in plane and then placed on the other and both structures have same bond connectivity, molecular formula. Hence, I & I are the same compound. same

Stroucture-I 1 4 & & & are the chiral Centers. H. al For , chinal center: H a x Il notation »R- configuration. Alconding to cip sule: priority order as by exd lowest priority group above the plane & Anticlockwise rotation - R-configuration. & -chinal center: For , - R- Configuration Tunel @ H @ H According to CIP Rule: Priority orden: a) b) exd lowest priority group above the plane Anti clockwise rotation = R- configuration. strone ture - II aroe the chiral centers. ₂ & ₃ 2 3 Jy u

For & -chinal center: H rotation nel H According to CIP Rule: R- configuration. Priority order: a) b) e) d Lowest priority group below the plane = clockwise rotation R- configuration: For & chiral center: @H => R- configuration. © According to CIP Rule: Prionity order: a> 6) e) d Lowest priority group above the plane =) Anti clock wise rotation ) R- configuration. lu@ Hi a Hence, the correct IUPAC name compound -I: (22, 3 R)-2, 3-dichloropentane, compoun d-I: (2R, 3R) -2,3-dichloropentane.
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