Page 783 - Advanced Organic Chemistry Part A - Structure and Mechanisms, 5th ed (2007) - Carey _ Sundberg

766 to a 7-line spectrum? (3) What would be the nature of the process that converts
the 7-line spectrum to a 4-line spectrum?
CHAPTER 8
Aromaticity

13-A 13-B 13-C

8.14. When alcohol 14-A is dissolved in FSO Hat −136 C and then brought

3
13
to −110 C, it gives rise to a C-NMR spectrum having five lines in the intensity

ratio 2:1:2:2:2.
a. Suggest several possible structures for this cation and discuss stabilizing
features that might favor a particular structure.

OH
14-A

a b
2
9
3 1
1.489 1.393
α
8 100.0
1.411 1.542
(93.2)
β γ
4 1.483
170.4 169.8
(174.6)
6 (172.5)
1.380
2.147 7
5
c
C2 C1
C9

2
Fig. 8.P14. (a) Bond lengths and (b) inter-ring angles for minimum-energy cation; (c) − (r)
in the C(1)−C(2)−C(9) plane. Reproduced by permission of the American Chemical Society
Bond Orders: 1,2: 1.04; 2,3:1.59; 3,4: 1.57; 1,6:0.94; 1,9: 1.04; 8,9:1.56; 2,9:0.34.