Advices For Studying Organic Chemistry

(R)-(–)-2-Butanol (S)-(+)-2-Butanol

[]α^25 D = –13.52° [α]^25 D = +13.52°

C

CH 3

H

C 2 H (^5)
H C
CH 3
HOH 2 C CH 2 OH
C 2 H (^5)
(R)-(+)-2-Methyl-1-butanol (S)-(–)-2-Methyl-1-butanol

[]α^25 D = +5.756° [α]^25 D = –5.756°

C

CH 3

H

C 2 H (^5)
H C
CH 3
ClH 2 C CH 2 Cl
C 2 H (^5)
(R)-(–)-1-Chloro-2-methylbutane (S)-(+)-1-Chloro-2-methylbutane

[]α^25 D = –1.64° [α]^25 D = +1.64°

3. No correlation exists between the configuration of enantiomers and the
   direction of optical rotation.


4. No correlation exists between the (R) and (S) designation and the direction of
   optical rotation.


5. Specific rotations of some organic compounds:

Specific Rotations of Some Organic Molecules

Compound [α]D (degrees) Compound [α]D (degrees)

Camphor +44.26 Penicillin V +223

Morphine –132 Monosodium glutamate +25.5

Sucrose +66.47 Benzene 0

Cholesterol –31.5 Acetic acid 0

5.8 THE ORIGIN OF OPTICAL ACTIVITY

1. Almost all individual molecules, whether chiral or achiral, are theoretically
   capable of producing a slight rotation of the plane of plane-polarized light.