STRUCTURAL EFFECTS ON GRUNWALD–WINSTEIN CORRELATIONS
723
(
CH ), 30·5 (CH ), 29·8 ppm (CH ); HRMS (EI), calculated
Kinetic studies
The preparation of solvents and kinetic procedures followed
3
3
3
for C H O, 128·1202; found, 128·1177.
8
16
22
the methods described previously.
1-Chloro-1,3,3-trimethylcyclopentane (7). A solution
of 11 (1·00 g, 7·8 mmol) in pentane (10 ml) was treated with
dry HCl gas at 0 °C for 40 min. The reaction mixture was
dried with CaCl and excess HCl was swept off with N .
REFERENCES
1. (a) S. Winstein, E. Grunwald and H. W. Jones, J. Am. Chem.
Soc. 73, 2700–2707 (1951); (b) F. L. Schadt, T. W. Bentley and
P. v. R. Schleyer, J. Am. Chem. Soc. 98, 7667–7674 (1976); (c)
T. W. Bentley and P. v. R. Schleyer, Adv. Phys. Org. Chem. 14,
2
2
Filtration followed by evaporation of solvent afforded 7 as
1
a colorless liquid (1·06 g, 94%); H NMR (CDCl ), ␦ 1·01
(
3
13
s, 3H), 1·19 (s, 3H), 1·5–2·3 (m, 6H), 1·68 ppm (s, 3H); C
1
–67 (1977); (d) T. W. Bentley and G. Llewellyn, Prog. Phys.
NMR (CDCl ), ␦ 78·2 (C), 58·5 (CH ), 44·3 (CH ), 40·4
3
2
2
Org. Chem. 17, 121–158 (1990); (e) D. N. Kevill and M. J.
D’Souza, J. Phys. Org. Chem. 5, 287–294 (1992); (f) K.-T.
Liu, J. Chin. Chem. Soc. 42, 607–615 (1995); (g) D. N. Kevill,
in Advances in Quantitative Structure–Property Relatonships,
edited by M. Charton, Vol. 1, pp. 81–115. JAI Press,
Greenwich, CT (1996).
(
CH ), 38·8 (C), 32·3 (CH ), 31·3 (CH ), 30·9 ppm (CH ).
2 3 3 3
13
The crude chloride was essentially pure by C NMR
spectroscopy and used for rate studies without further
purification.
2
. (a) D. N. Kevill and S. W. Anderson, J. Org. Chem. 56,
1
845–1850 (1991); (b) D. N. Kevill and M. J. D’Souza, J.
Chem. Res. (S) 174–175 (1993); (c) D. N. Kevill and G. M. L.
Lin, J. Am. Chem. Soc. 101, 3916–3919 (1979).
Product of solvolysis of 4
3. D. N. Kevill and D. C. Hawkinson, J. Org. Chem. 55,
394–5399 (1990); D. N. Kevill and A. R. Pinhas, J. Org.
5
Methanolysis. A solution of 4 (0·297 g, 2·00 mmol) in
Chem. 58, 197–201 (1993); D. N. Kevill and R. W. Bahnke, J.
Chem. Soc., Perkin Trans. 2, 1995, 1777–1780.
. E. Grunwald and S. Winstein, J. Am. Chem. Soc. 70, 846–854
0
5
·050
M
2,6-lutidine in methanol (50 ml) was kept at
4
5
6
7
0·0 °C for 160 min (10 half-lives). The reaction mixture
(
1948).
. T. W. Bentley and G. E. Carter, J. Am. Chem. Soc. 104,
741–5747 (1982).
was mixed with pentane, washed with 10% NaCl and dried.
GLC analysis showed the formation of a mixture of the two
expected olefins (74%) and the expected methyl ether
26%). Most of the pentane was slowly distilled off through
a 20 cm Vigreux column, and the residue was examined by
5
. K.-T. Liu, H.-C. Sheu, H.-I. Chen, P.-F. Chiu and C.-R. Hu,
Tetrahedron Lett. 31, 3611–3614 (1990).
. K. Takeuchi, Y. Ohga, T. Ushino and M. Takasuka, J. Phys.
Org. Chem. 9, 777–779 (1996).
(
1
H NMR spectroscopy. The formation of 2-methoxy-
2
,4,4-trimethylpentane was confirmed by the methoxy
signal at ␦ 3·17. The ratio between the two olefins,
,4,4-trimethylpent-1-ene and 2,4,4-trimethylpent-2-ene,
8. (a) V. J. Shiner, Jr, J. Am. Chem. Soc. 83, 240–243 (1961); (b)
T. W. Bentley, J.-P. Dau-Schmidt, G. Llewellyn and H. Mayr, J.
Org. Chem. 57, 2387–2392 (1992); (c) H. C. Brown and F. J.
Chloupek, J. Am. Chem. Soc. 85, 2322–2324 (1963).
2
was determined by the integration of the olefinic protons.
9
. (a) A. H. Fainberg and S. Winstein, J. Am. Chem. Soc. 78,
770–2777 (1956); (b) V. J. Shiner, Jr, W. Dowd, R. D. Fisher,
2
S. R. Hartshorn, M. A. Kessick, L. Milakofsky and M. W.
Rapp, J. Am. Chem. Soc. 91, 4838–4843 (1969); (c) P. Haake
and P. S. Ossip, J. Am. Chem. Soc. 93, 6924–6930 (1971); (d)
D. E. Sunko and I. Szele, Tetrahedron Lett. 3617–3620 (1972);
Acetolysis. A solution of 4 (0·297 g, 2·00 mmol) in
0
(
·050
M
NaOAc in acetic acid (50 ml) was heated for 10 h
15 half-lives). The reaction mixture was mixed with
pentane, washed with water and saturated NaHCO solution
3
(e) T. W. Bentley, C. T. Bowen, W. Parker and C. I. F. Watt, J.
and dried. Product analysis was conduced in the manner
described under Methanolysis. The formation of the
expected acetate was confirmed by the agreement of the
GLC retention time with that of an authentic sample.
Chem. Soc., Perkin Trans. 2 1980, 1244–1252.
1
0. (a) H. C. Brown and R. S. Fletcher, J. Am. Chem. Soc. 71,
1845–1854 (1949); (b) H. C. Brown and H. L. Berneis, J. Am.
Chem. Soc. 75, 10–14 (1953).
1
1. H. C. Brown, The Nonclassical Ion Problem, with comments
by P. v. R. Schleyer, pp. 123–149. Plenum Press, New York
(1977).
Authentic 1,1,3,3-tetramethylbutyl acetate. This was
prepared by treating 2,4,4-trimethylpentan-2-ol (0·400 g.
12. J. S. Lomas, M. J. D’Souza and D. N. Kevill, J. Am. Chem.
Soc. 117, 5891–5892 (1995).
3
·07 mmol) with acetic anhydride (0·47 g, 4·6 mmol) in
1
3. D. N. Kevill, S. W. Anderson and E. K. Fujimoto, in
Nucleophilicity, edited by J. M. Harris and S. P. McManus,
Advances in Chemistry Series, No. 215, pp. 269–283.
American Chemical Society, Washington, DC (1987).
triethylamine (0·64 ml) in the presence of 4-(N,N-dimethy-
lamino)-pyridine (0·038 g, 0·31 mmol) at room temperature
overnight. The reaction mixture was diluted with pentane,
washed with 10% HCl and saturated NaCl solution and
dried. Evaporation of the solvent afforded essentially pure
1
4. J. P. Richard, V. Jagannadham, T. L. Amyes, M. Mishima and
Y. Tsuno, J. Am. Chem. Soc. 116, 6706–6712 (1994).
13
1
,1,3,3-tetramethylbutyl acetate; C NMR (CDCl ), ␦ 170·4
3
15. R. C. Bingham and P. v. R. Schleyer, J. Am. Chem. Soc. 93,
3189–3199 (1971).
(
CO), 83·6 (C), 52·3 (CH ), 31·4 (C), 31·3 (CH ), 28·3
2
3
(
CH ), 22·7 ppm (CH ).
16. K. Takeuchi and Y. Ohga, Bull. Chem. Soc. Jpn. 69, 833–851
3
3
©
1997 John Wiley & Sons, Ltd.
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, VOL. 10, 717–724 (1997)