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Helvetica Chimica Acta – Vol. 89 (2006)
less oil. Rf (cyclohexane/AcOEt 1:3) 0.36. IR (CHCl3): 3442w, 3010w, 1721s, 1610w, 1408w. 1H-NMR (300
MHz, CDCl3): 1.26 (ddd, J=13.4, 5.6, 1.9, HÀC(7)); 1.57–1.64 (m, exchange with D2O, OH); 1.84 (dt,
J=13.7, 3.4, H’ÀC(7)); 1.94–2.02 (m, HÀC(3), HÀC(8)); 2.27 (dd, J=19.0, 2.2, H’ÀC(3)); 3.03–3.12
(m, HÀC(1), HÀC(4)); 3.49–3.57 (m, addn. of D2O ! dd, J=10.3, 8.7), 3.71–3.78 (m, addn. of D2O
! dd, J=10.9, 5.9) (CH2ÀC(8)); 6.20 (tt, J=7.4, 0.8), 6.44 (td, J=7.8, 1.3) (HÀC(5), HÀC(6)). 13C-
NMR (75 MHz, CDCl3): 26.27 (t, C(7)); 33.26 (d, C(8)); 34.81 (t, C(3)); 37.82 (d, C(4)); 48.52 (d,
C(1)); 64.29 (t, CH2ÀC(8)); 128.06, 138.72 (2d, C(5), C(6)); 212.81 (s, C(2)). HR-ESI-MS: 327.1562
([2M+Na]+, C18H24NNaOþ4 ; calc. 327.1572).
(1RS,4RS,8SR)-8-{[(tert-Butyl)diphenylsilyloxy]methyl}bicyclo[2.2.2]oct-5-en-2-one (9). A soln. of 8
(545 mg, 3.6 mmol) and 1H-imidazole (370 mg, 5.4 mmol) in DMF (20 ml) at 08 was treated with
tBuPh2SiCl (985 ml, 3.79 mmol), warmed to 238, stirred for 48 h, diluted with H2O (40 ml), and extracted
with Et2O (1 × 30 ml, 2 × 20 ml). The combined org. layers were dried (Na2SO4) and evaporated. FC (hex-
ane/AcOEt) 5 :1) gave 9 (1.4 g, quant.). Colourless oil. Rf (cyclohexane/AcOEt 5 :1) 0.56. IR (CHCl3):
1
3011w, 1964w, 1896w, 1823w, 1720s, 1602m, 1472w, 1428m, 1113s. H-NMR (300 MHz, CDCl3): 1.06 (s,
t-Bu); 1.16 (ddd, J=13.7, 7.6, 1.7, HÀC(7)); 1.74 (ddd, J=13.7, 10.9, 3.8, H’ÀC(7)); 1.89 (ddd,
J=18.7, 3.3, 1.7, HÀC(3)); 1.96–2.06 (m, HÀC(8)); 2.14 (dd, J=18.7, 1.9, H’ÀC(3)); 3.02–3.06 (m,
irrad. at 1.16 ! br. dd, J=6.3, 3.9, HÀC(1)); 3.11–3.13 (m, irrad. at 2.01 ! d, J=6.2, HÀC(4)); 3.46
(t, Jꢀ10.2, irrad. at 2.01 ! d, J=11.5), 3.74 (dd, J=10.2, 5.8, irrad. at 2.01 ! d, J=10.0) (CH2ÀC(8));
6.17 (br. t, J=7.9, irrad. at 3.04 ! d, J=8.1, irrad. at 3.12 ! dd, J=8.1, 5.0, HÀC(6)); 6.62 (br. t,
J=7.7, irrad. at 3.04 ! dd, J=8.1, 5.4, irrad. at 3.12, d, J=8.1, HÀC(5)); 7.35–7.74 (m, 10 arom. H).
13C-NMR (300 MHz, CDCl3): 19.45 (s, Me3C); 25.90 (t, C(7)); 27.12 (q, Me3C); 33.57 (d, C(8)); 34.78
(t, C(3)); 38.01 (d, C(4)); 48.77 (d, C(1)); 65.34 (t, CH2ÀC(8)); 127.65 (2d); 127.69 (2d); 128.09 (d);
129.07 (d); 129.73 (d); 133.41 (2s); 134.70 (d); 135.44 (3d); 138.84 (d); 212.87 (s, C(2)). HR-ESI-MS:
413.1910 ([M+Na]+, C25H30NaO2Si+; calc. 413.1913). Anal. calc. for C25H30O2Si (390.60): C 76.88, H
7.74; found: C 76.69, H 7.65.
(1RS,4SR,5SR,6RS,8SR)- and (1RS,4SR,5RS,6SR,8SR)-8-{[(tert-Butyl)diphenylsilyloxy]methyl}-5,
6-dihydroxybicyclo[2.2.2]octan-2-one (10 and 11, resp.). A soln. of 9 (1.4 g, 3.6 mmol), NMO (590 mg,
4.3 mmol), H2O (4 ml), and MeCN (4 ml) in acetone (20 ml) was treated with 2.5% OsO4 in t-BuOH
(0.1 ml), stirred for 22 h at 228, poured into a 20% aq. NaHSO3 soln. (50 ml) at 08, and stirred for
10 min. After evaporation of acetone, the residual soln. was extracted with Et2O (1 × 100 ml, 3 ×
30 ml). The combined org. layers were dried (MgSO4) and evaporated. FC (hexane/AcOEt 1:1) yielded
10/11 78 :22 (1.33 g, 86%). Colourless glass.
Data of 10/11 78 :22. Rf (cyclohexane/AcOEt 1:2) 0.59. IR (CHCl3): 3603w, 3062w, 2932m, 1968w,
1897w, 1829w, 1728s, 1605w, 1472w, 1427w, 1100s. 1H-NMR (300 MHz, CDCl3): 1.04 (s, t-Bu);
1.00–1.12 (m, 0.22 H), 1.20 (ddd, J=14.3, 5.6, 2.8, 0.78 H) (HÀC(7)); 1.84 (td, J=14.0, 3.1, 0.78 H),
1.94–2.05 (m, 0.22 H) (H’ÀC(7)); 1.94–2.05 (m, HÀC(8)); 2.16 (dd, J=19.9, 2.2, 0.78 H), 2.26 (ddd,
J=17.7, 10.2, 4.1, 0.22 H) (HÀC(3)); 2.38–2.59 (m, HÀC(1), H’ÀC(3), HÀC(4)); 2.88 (br. s, 0.44 H),
3.09 (br. s, 1.56 H) (2 OH); 3.43–3.65 (m, CH2ÀC(8)); 3.93 (br. ddd, J=7.8, 5.0, 2.5, 0.22 H) 4.03–4.06
(m, 1 H), 4.20 (br. td, J=8.1, 4.0, 0.78 H) (HÀC(5), HÀC(6)); 7.36–7.65 (10 arom. H). 13C-NMR
(75 MHz, CDCl3): major and minor isomer: 23.62 (t, C(7)); 26.97 (s, Me3C); 33.73 (t, C(3)); 67.93,
69.52 (2d, C(5), C(6)); 127.70 (4d); 129.74 (2d); 133.24 (2s); 135.43 (4d); major isomer: 19.35 (s,
Me3C); 34.51 (d, C(8)); 36.51 (d, C(4)); 50.83 (d, C(1)); 65.01 (t, CH2ÀC(8)); 214.91 (s, C(2)); minor iso-
mer: 19.97 (s, Me3C); 36.60 (d, C(8)); 38.15 (d, C(4)); 50.59 (d, C(1)); 65.63 (t, CH2ÀC(8)); 214.10 (s,
C(2)). HR-ESI-MS: 447.1957 ([M+Na]+, C25H32NaO4Si+; calc. 447.1968). Anal. calc. for C25H32O4Si
(424.61): C 70.72, H 7.60; found: C 70.55, H 7.67.
(1RS,2SR,6RS,7RS,10SR)-
and
(1RS,2RS,6SR,7RS,10RS)-10-{[(tert-Butyl)diphenylsilyloxy]-
methyl}-4,4-dimethyl-3,5-dioxatricyclo[5.2.2.02,6]undecan-8-one (12 and 13, resp.). A soln. of 10/11
78 :22 (1.29 g, 3.04 mmol), pyridinium p-toluenesulfonate (5 mg), and 2,2-dimethoxypropane (1.7 g,
16.3 mmol) in CH2Cl2 (15 ml) was stirred for 16 h at 208 and evaporated. FC (hexane/AcOEt 10 :1)
gave 12 (1.06 g, 75%) and 13 (332 mg, 24%).
Data of 12. Colourless glass. Rf (cyclohexane/AcOEt 3 :1) 0.47. IR (CHCl3): 2933m, 1961w, 1894w,
1
1823w, 1729s, 1602w, 1472w, 1428m, 1089s. H-NMR (500 MHz, CDCl3; assignment based on a DQF-
COSY and a HSQC spectrum): 1.04 (s, t-Bu); 1.20 (ddd, J=14.6, 6.1, 2.8, HÀC(11); 1.35, 1.42 (2s, Me2-