J. CHEM. RESEARCH (S), 1998 43
+
•
tography on silica gel (eluent: light petroleum–ethyl acetate, from
40:1 to 15:1 v/v) to give 4 as a yellow oil in yields of 61 to 72%
(Found: C, 78.81; H, 10.32. C10H16O requires C, 78.94; H, 10.53%).
+
•
3
–H+
•
•
1 or 2
v
max/cmꢀ1 (film): 3340 (O•H), 1440 (C‚C), 1220 (C‚CH2). dH
([2H6]DMSO) 1.24 (3 H, s), 1.52 (1 H, m), 1.73 (2 H, m), 1.81 (3 H,
s), 2.13 (2 H, m), 3.45 (1 H, br s, OH), 4.68 (2 H, m), 5.20 (1 H, m),
5.72 (1 H, d, J 10.7 Hz). dC ([2H6]DMSO) 149.9, 134.3, 128.2, 114.2,
75.4, 46.1, 31.7, 29.0, 26.2, 21.7; m/z 152 (Mǹ), 134, 119, 91, 79, 43,
41. The 1H NMR spectroscopic data are consistent with those
reported for 4.5
+
+
•
excess of 3
+
+H+
We are grateful to the National Natural Science Founda-
tion of China for financial support.
4
Received, 23rd July 1997; Accepted, 22nd September 1997
Paper E/7/05326F
6
Scheme 2
References
The radical cation intermediate formed initially undergoes
cyclization, deprotonation and dehydrogenation (by excess of
1 N. L. Bauld, Acc. Chem. Res., 1987, 20, 371 and references cited
therein.
.
3ǹ ) to give a cyclic triene, which protonates to form the
2 G. Stufflebeme, K. T. Lorenz and N. L. Bauld, J. Am. Chem. Soc.,
1986, 108, 4234.
carbocationic intermediate 6. Attack by a water molecule at
the cationic centre opposite the isopropenyl group and
deprotonation would produce 4.
3 (a) J. P. Dinnocenzo and M. Schmitlel, J. Am. Chem. Soc., 1987,
109, 1567; (b) J. P. Dinnocenzo and D. A. Conlon, J. Am. Chem.
Soc., 1988, 110, 2324.
4 Q. X. Guo, W. Wang, W. Yu, Y. C. Liu and Y. D. Wu, in
preparation.
5 T. Sato and E. Murayama, Bull. Chem. Soc. Jpn., 1974, 47, 715.
6 (a) K. Stephan, J. Prakt. Chem., 1898, 58, 109; (b) O. Zertschel,
Ber. Dtsch. Chem. Ges., 1906, 39, 1780.
7 (a) R. Croteau, Chem. Rev., 1987, 87, 929; (b) D. E. Cane, Acc.
Chem. Res., 1985, 18, 220; (c) D. E. Cane, Tetrahedron, 1980, 36,
1109.
8 (a) W. Rittersdorf and F. Cramer, Tetrahedron, 1967, 23, 3015;
1968, 24, 43; (b) O. Cori, L. Chayet, L. M. Perez, C. A. Bunton
and D. Hachey, J. Org. Chem., 1986, 51, 1310.
9 (a) Q. X. Guo, X. Z. Qin, J. T. Wang and F. Williams, J. Am.
Chem. Soc., 1988, 110, 1974; (b) W. Adam, S. Grabowski, M. A.
Miranda and M. Rubenacker, J. Chem. Soc., Chem. Commun.,
1988, 142; (c) T. Miyashi, A. Konno and Y. Takahashi, J. Am.
Chem. Soc., 1988, 110, 3676.
Experimental
Melting points were uncorrected. Elemental analyses were
carried out on an Italian-1106 elemental analytical apparatus. IR
1
spectra were recorded on a Nicolet FT-170SX spectrometer. H
and 13C NMR and 13C-DEPT spectra were obtained on a Bruker
DMX-500 spectrometer (500.0 MHz for 1H NMR, 125.0 MHz for
13C NMR and 13C-DEPT) using [2H6]DMSO as solvent and tetra-
methylsilane (TMS) as internal reference. Mass spectra were
determined on a VG-ZAB-HS mass spectrometer (EI).
1 and 2 were purchased from TCI Chemical Co. and used with-
out further purification. Compound
3 was synthesized as
described;11 mp 143–144 °C (decomp.) (Found: C, 26.58; H, 1.46.
C18H12Br3Cl6NSb requires C, 26.50; H, 1.50%). All solvents were
purified and dried according to standard procedures.12
cis-p-Mentha-2,8-dien-1-ol (4). To a solution of 1 or 2 (2.0 mmol)
in anhydrous acetonitrile (35.0 ml) 3 (4.8 mmol) was added. The
mixture was stirred at room temperature for 2 h under argon and
checked by TLC. It was then poured into saturated sodium carbon-
ate–methanol solution (15.0 ml), and extracted with trichlorome-
thane (total 75 ml). The organic layer was washed with water and
dried with anhydrous magnesium sulfate and the solvent was
removed. The oily residue was separated by column chroma-
10 U. Hoffmann, Y. Gao, B. Pandey, S. Klinge, K. D. Warzecha, C.
Kruger, H. D. Roth and M. Demuth, J. Am. Chem. Soc., 1993,
115, 10358.
11 F. A. Bell, A. Ledwith and D. C. Sherrington, J. Chem. Soc. C,
1969, 2719.
12 D. D. Perrin and W. L. F. Armarego, Purification of Laboratory
Chemicals, Pergamon Press, New York, 3rd edn, 1988.