5710 J . Org. Chem., Vol. 63, No. 16, 1998
Notes
anhydrous Na2SO4, and evaporation of the solvent gave a
mixture of a white solid (12, 127 mg) and a yellow oil (10 and
11 in a 2:1 ratio, 459 mg). The sample consisting of just 10 and
11 was obtained by washing the oil off the solid with hexanes.
For 10: 1H NMR δ 2.29 (1H, d, J ) 13.2 Hz), 2.07 (1H, d, J )
13.2 Hz), 1.29 (3H, s), 1.16 (3H, s), 0.19 (9H, s); 11B NMR (CD2-
Cl2) δ 20.3; 13C NMR (CD2Cl2) (selected signals) δ 215.5, 99.3,
88.1, 82.3, 39.6, 34.8, 34.5, 26.0, 24.1, 22.6, 22.3, 22.1, 0.97; 29Si
NMR (CD2Cl2) δ 16.5. For 11: 1H NMR δ 2.32 (1H, d, J ) 13.5
Hz), 2.12 (1H, d, J ) 13.5 Hz), 1.30 (3H, s), 1.18 (3H, s); 11B
NMR (CD2Cl2) δ 21.9. The mixture of 10 and 11 (0.584 g) was
stirred in TFA (3.0 mL) at room temperature for 20 h. Workup
provided a brown oil (0.408 g). 1H NMR analysis showed the
presence of 13 and 14 (1.5:1).
MeOH treatment. For this mixture: 1H NMR δ 3.44 (OH), 2.18
(1H, d, J ) 12.8 Hz), 2.17 (1H, d, J ) 12.9 Hz), 1.91 (2H, d, J )
12.8 Hz), 1.87-1.84 (2H, m), 1.36 (6H, s), 1.155 (3H, s), 1.153
(3H, s), 0.90 (6H, d, J ) 6.4 Hz); 13C NMR δ 220.0 (0), 92.6 (0),
92.5 (0), 74.0 (0), 55.2 (0), 38.6 (2), 38.0 (2), 34.4 (2), 31.7 (2),
29.2 (2), 27.3 (1), 27.0 (1), 20.9 (2), 20.6 (2), 24.7 (3), 22.5 (3),
20.9 (3).
(1′R*,2′R*)-2-H yd r oxy-4,4-d im et h yl-2-(1-h yd r oxy-2-m e-
th ylcycloh exyl)cyclobu ta n on e (26): yellow solid; mp 113.5-
116 °C; 1H NMR δ 3.60 (OH), 2.15 (1H, dd, J ) 0.6, 12.8 Hz),
2.00 (1H, d, J ) 12.8 Hz), 1.66 (1H, br m), 1.36-1.17 (8H, m),
1.37 (3H, s), 1.16 (3H, s), 1.00 (3H, d, J ) 6.8 Hz); 13C NMR δ
218.9 (0), 94.4 (0), 74.1 (0), 55.3 (0), 39.0 (2), 36.3 (1), 34.0 (2),
30.9 (2), 25.7 (2), 24.8 (3), 21.5 (3), 21.0 (2), 17.5 (3). Stirring 26
(9 mg) in TFA (1 mL) at room temperature for 7 h provided only
2 mg of a brown oil, which consisted of a 1:1 mixture of 21b and
28a ,b (1:1).
(1′R*,2′S*)-2-Hyd r oxy-4,4-d im eth yl-2-(1-h yd r oxy-2-m eth -
ylcycloh exyl)cyclobu ta n on e (27): white solid; mp 139-141.5
°C; 1H NMR δ 2.45 (OH), 2.44 (1H, d, J ) 12.3 Hz), 1.84 (1H, d,
J ) 12.3 Hz), 1.91 (1H, br m), 1.73-1.63 (2H, m), 1.63-1.47
(2H, m), 1.47-1.36 (4H, m), 1.35 (3H, s), 1.20 (3H, s), 1.03 (3H,
d, J ) 7.5 Hz); 13C NMR δ 218.5 (0), 94.3 (0), 74.7 (0), 55.4 (0),
38.4 (2), 34.7 (1), 29.2 (2), 27.1 (2), 25.1 (3), 21.3 (3), 20.9 (2),
19.6 (2), 15.8 (3). Diol 27 (11 mg) was dissolved in trifluoroacetic
acid-d at room temperature. 1H NMR after only 5 min revealed
rearrangement to 21a was complete. Aqueous workup provided
21a as a yellow oil (10 mg).
2-Ben zyl-2,4,4-tr im eth yl-1,3-cyclop en ta n ed ion e (17): yel-
1
low oil; H NMR δ 7.27-7.14 (3H, m), 7.08-6.98 (2H, m), 2.99
(1H, d, J ) 12.8 Hz), 2.92 (1H, d, J ) 12.8 Hz), 2.43 (1H, d, J )
18.4 Hz), 1.74 (1H, d, J ) 18.3 Hz), 1.27 (3H, s), 1.12 (3H, s),
0.62 (3H, s); 13C NMR δ 221.3 (0), 216.9 (0), 136.3 (0), 130.0 (2C,
1), 128.4 (2C,1), 127.1 (1), 58.6 (0), 51.8 (2), 46.1 (0), 42.5 (2),
26.7 (3), 23.0 (3), 22.4 (3).
(5R*,7S*)-2,2,7-Tr im eth ylsp ir o[4.5]d eca n e-1,4-d ion e (24):
very pale yellow crystals from EtOAc-hexane; mp 59.5-61 °C;
1H NMR δ 2.61 (2H, s), 1.93 (1H, br m), 1.81 (1H, m), 1.72 (1H,
m), 1.68-1.55 (2H, m), 1.53 (1H, m), 1.48 (1H, apparent dq, J )
3.9, 12.9 Hz), 1.222 (3H, s), 1.215 (3H, s), 1.15 (1H, d, J ) 13.2
Hz), 0.92 (1H, apparent dt, J ) 4.8, 14.1 Hz), 0.86 (3H, d, J )
6.9 Hz); 13C NMR δ 220.1 (0), 216.3 (0), 56.0 (0), 50.4 (2), 46.4
(0), 38.3 (2), 33.7 (2), 30.5 (2), 26.7 (1), 25.5 (3), 25.3 (3), 22.4
(3), 21.1 (2). For the 4-(2,4-dinitrophenylhydrazone) deriva-
tive: orange crystals from MeCN-CH2Cl2-hexane, mp 231-
233 °C; 1H NMR δ 11.11 (1H, br s), 9.14 (1H, d, J ) 2.6 Hz),
8.39 (1H, dd, J ) 2.5, 9.5 Hz), 7.88 (1H, d, J ) 9.5 Hz), 2.77
(2H, s), 2.18-1.88 (2H, m), 1.82 (1H, m), 1.75-1.50 (4H, m), 1.33
(1H, apparent triplet, J ) 12.8 Hz), 1.25 (3H, s), 1.24 (3H, s),
1.01 (1H, apparent dq, J ) 3.4, 12.9 Hz), 0.92 (3H, d, J ) 6.6
Hz); 13C NMR δ 220.3 (0), 164.7 (0), 145.0 (0), 138.0 (0), 130.3
(1), 129.3 (0), 123.4 (1), 116.4 (1), 53.8 (0), 46.0 (0), 40.3 (2), 38.8
(2), 33.8 (2), 32.1 (2), 26.7 (1), 25.8 (2C, 3), 22.6 (3), 21.3 (2).
(1′R*,3′R*)-2-H yd r oxy-4,4-d im et h yl-2-(1-h yd r oxy-3-m e-
th ylcycloh exyl)cyclobu ta n on e (25a ,b). A 1:1 mixture of
epimers (at C-2) was obtained by aqueous workup after the HF/
Ack n ow led gm en t. This work was supported by a
grant from the Natural Sciences and Engineering
Research Council of Canada.
Su p p or tin g In for m a tion Ava ila ble: Experimental de-
tails, additional characterization data, and NMR spectra for
new compounds and for byproducts (22 pages). This material
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