Advices For Studying Organic Chemistry

Figure 6.10 Electrostatic potential maps for (a) tert-butyl (3°), (b) isopropyl (2°), (c)
ethyl (1°), and (d) methyl carbocations show the trend from greater to
lesser delocalization (stabilization) of the positive charge. (The
structures are mapped on the same scale of electrostatic potential to
allow direct comparison.)

6.13 THE STEREOCHEMISTRY OF SN 1 REACTIONS

1. The carbocation has a trigonal planar structure ⇒ It may react with a
   nucleophile from either the front side or the back side:

H 2 O+ H 2 O C OH 2 OH+ 2

Same product

H 3 CCH 3

CH 3

C

CH 3

CH 3

CH 3 C

H 3 C

H 3 C

H 3 C

back side

attack

front side

+ attack

1) With the tert-butyl cation it makes no difference.

2) With some cations, different products arise from the two reaction possibilities.

6.13A REACTIONS THAT INVOLVE RACEMIZATION

1. Racemization: a reaction that transforms an optically active compound into a
   racemic form.

1. Complete racemization and partial racemization:


2. Racemization takes place whenever the reaction causes chiral molecules to