The Grunwald-Winstein type correlation for 2-chloro-2,4,4-trimethylpentane: A simple tertiary alkyl chloride that shows essentially limiting behaviour in solvolysis
✍ Scribed by Ken'ichi Takeuchi; Yasushi Ohga; Takuhiro Ushino; Masaaki Takasuka
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 226 KB
- Volume
- 9
- Category
- Article
- ISSN
- 0894-3230
No coin nor oath required. For personal study only.
✦ Synopsis
Evaluation of the rates of solvolysis of 2-chloro-2,4,4-trimethylpentane (4) in 17 solvents on the basis of the Grunwald-Winstein type equation [log(k/k,) = lNT + my,, + el gives an excellent correlation with 1 = -0.01 f 0.02 and rn = 0.74i 0.01. The neopentyl group in 4 more effectively shields the rear side of the reaction center than the tert-butyl group in 2-chloro-2,3,3-trimethylbutane. The rate ratio between 4 and 2chloro-2-methylpropane (3) at 25 "C is 275 in trifluoroethanol and predicted to increase to 950 in trifluoroacetic acid. The previous 4:3 rate ratio of 22 in 80% ethanol evidently underestimated the B-strain effect on the solvolysis rate of 4 by a factor of at least 40.