F. K. Zinn et al. / Tetrahedron Letters 42 (2001) 2415–2417
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6. Organoselenium Chemistry; Back, T. G., Ed.; Oxford Uni-
versity Press: Oxford, 1999.
7. Petragnani, N. Tellurium in Organic Synthesis; Academic
Press: London, 1994.
solvent was evaporated. The residue was distilled in a
Kugelrohr oven under vacuum. Yield of 3-tert-butylcyclo-
hexanone: 490 mg (83%). 1H NMR (300 MHz, CDCl3,
ppm): l 0.92 (s, 9H), 1.21–1.23 (m, 1H), 1.41–1.62 (m,
2H), 1.82–2.21 (m, 4H), 2.3–2.48 (m, 2H); 13C NMR (75
MHz, CDCl3, ppm): l 25.61, 26.17, 27.14, 32.68, 41.27,
43.61, 49.35, 212.60; LRMS m/z (relative intensity, %):
154.2 (M+, 16%), 139.2 (3%), 121.2 (3%), 98.2 (97%), 83
(42%), 57 (100%).
8. Typical procedure: In a two-necked 50 mL flask under
nitrogen and magnetic stirring was placed elemental tel-
lurium (511 mg, 4 mmol) in dry THF (5 mL). To this
suspension at room temperature was added n-butyllithium
(3.08 mL of a 1.3 M solution in hexane, 4 mmol). A yellow
solution formed. This solution was transferred via cannula
to a second two-necked 50 mL flask under nitrogen and
magnetic stirring containing a suspension of CuCN (358
mg, 4 mmol) in THF (5 mL) at −78°C. The mixture was
kept at this temperature for 15 minutes and then t-butyl-
lithium (6.15 mL of a 0.65 M solution in hexane, 4 mmol)
was added. The cooling bath was removed and the mixture
was stirred until a clear solution formed. Then it was
cooled again to −78°C and cyclohexenone (370 mg, 3.8
mmol) was added. The mixture was allowed to reach the
room temperature and maintained under stirring for 1 h.
A dark precipitate formed. The organic phase was diluted
with NH4Cl/NH4OH (3:1, 5 mL) and then with a 10%
solution of sodium hypochlorite (3×10 mL). The organic
phase was further washed with NH4Cl/NH4OH solution
until the blue color of the aqueous phase disappeared. The
organic phase was dried with magnesium sulfate and the
9. Typical procedure for the reaction using BF3·Et2O: The
same procedure described above for the preparation of the
cyanocuprate 4 was followed. Then BF3·Et2O (1.49 mL, 12
mmol) was added slowly at −78°C and the mixture was
kept at this temperature for 15 minutes, giving an orange
solution. Isophorone (498 mg, 3.6 mmol) was then added
and the mixture was stirred for 3 h at room temperature.
The work-up was identical to the one described above.
Yield of 3,5,5-trimethyl-3-butylcyclohexanone: 610 mg
(87%). 1H NMR (300 MHz, CDCl3, ppm): l 0.88 (t,
J=7.2 Hz, 3H), 0.98 (s, 3H), 1.02 (s, 3H), 1.03 (s, 3H),
1.19–1.28 (m, 6H), 1.45–1.63 (m, 2H), 2.06–2.18 (m, 4H);
13C NMR (75 MHz, CDCl3, ppm): l 14.20, 23.53, 26.21,
27.72, 30.93, 32.48, 36.15, 38.83, 44.79, 49.36, 53.32, 54.47,
213.10; LRMS m/z (relative intensity, %): 181.3 (1%),
139.3 (32%), 111.2 (3%), 97.2 (28%), 83.2 (100%), 55.0
(44%).
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