M.-E. J. Garcia, U. Fröhlich, U. Koert
FULL PAPER
toluene (30 mL) in a Schlenk tube. At –78 °C, a solution of enone
(17.12, 27.05 mmol) in toluene (200 mL) and sunsequently 1,3-bu-
tadiene (35 mL, 406 mmol) were added. Then the flask was sealed
and the reaction mixture warmed up to 20 °C within 36 h. The
reaction mixture was poured into a saturated aqueous solution of
NaHCO3 (100 mL). A saturated aqueous solution of NH4Cl
(100 mL) was added, and the mixture was filtered through a pad
of Celite. The aqueous phase was extracted with TBME
(3ϫ80 mL), and the combined organic phases were washed with
brine (2ϫ30 mL), dried with MgSO4 and concentrated in vacuo.
The residue was purified by flash chromatography (200 g, pentane/
(m, 2 H), 3.55–3.76 (m, 3 H), 3.90 (br., 1 H), 4.32 (m, 1 H), 7.15–
7.33 (m, 12 H), 7.46–7.61 (m, 8 H) ppm. 13C NMR (75 MHz,
CDCl3): δ = 19.4, 26.6, 27.0, 28.7, 29.2, 31.6, 34.7, 38.2, 47.6, 52.0,
53.5, 64.1, 66.8, 69.5, 127.6, 127.7, 129.4, 129.5, 129.6, 134.0, 134.1,
134.2, 134.4, 135.7, 135.8 ppm. IR (KBr): ν = 3391 (br), 2929 (m),
˜
2855 (m), 1739 (w), 1472 (w), 1427 (m), 1112 (s), 823 (m), 741 (m),
702 (s), 613 (w), 504 (m) cm–1. HRMS (ESI): calcd. for C44H56O4S-
i2Na [M + Na+] 727.3609; found 727.3623. 8Ј: Rf = 0.12 (pentane/
1
ethyl acetate, 9:1). H NMR (300 MHz, CDCl3): δ = 1.02 (s, 9 H),
1.10 (s, 9 H), 1.79–2.63 (m, 10 H), 3.50–4.38 (m, 6 H), 5.35 (m, 1
H), 5.72 (br., 1 H), 7.26–7.51 (m, 12 H), 7.52–7.69 (m, 8 H) ppm.
TBME, 19:1) to obtain 17.69 g (25.75 mmol, 95%) of ketone 7 as 13C NMR (75 MHz, CDCl3): δ = 19.2, 19.4, 26.9, 27.0, 28.2, 28.9,
a colorless oil. Rf = 0.43 (pentane/ethyl acetate, 19:1). [α]D = –14.26
29.4, 32.5, 35.0, 38.2, 43.6, 64.7, 65.4, 65.8, 75.2, 75.3, 127.7, 127.9,
(c = 5.19, CHCl3, 20 °C). H NMR (300 MHz, CDCl3): δ = 0.97 128.0, 129.7, 129.8, 130.2, 132.4, 132.7, 132.9, 133.7, 134.6, 135.6,
(s, 9 H), 1.05 (s, 9 H), 1.82–2.07 (m, 4 H), 2.18–2.35 (m, 1 H), 2.43– 135.8 ppm. IR (KBr): ν = 3398 (br.), 2929 (m), 2856 (m), 1719 (w),
1
˜
2.57 (m, 3 H), 2.64–2.76 (m, 2 H), 3.52 (dd, J = 10.3, 2.9 Hz, 1 H),
3.65–3.78 (m, 2 H), 4.09–4.18 (m, 1 H), 5.59–5.74 (m, 2 H), 7.24–
7.48 (m, 12 H), 7.54–7.68 (m, 6 H), 7.69–7.75 (m, 2 H) ppm. 13C
NMR (75 MHz, CDCl3): δ = 19.4, 19.6, 24.3, 26.7, 26.9, 27.1, 33.1,
34.5, 37.9, 47.8, 52.0, 58.8, 65.4, 125.1, 125.2, 127.6, 127.8, 129.5,
129.6, 129.8, 133.7, 133.8, 134.1, 135.7, 136.0, 209.7 ppm. IR (film):
1472 (w), 1427 (m), 1112 (s), 823 (w), 740 (w), 702 (s), 612 (w),
504 (m) cm–1. HRMS (ESI): calcd. for C44H56O4Si2Na [M + Na+]
727.3609; found 727.3630.
(2S,3S,4aR,6R,7R,8aS)-2,3-Bis(tert-butyldiphenylsilyloxymethyl)de-
calin-6,7-diol (9). Thiocarbonate Formation: To a solution of epox-
ide 8 (5.16 g, 7.31 mmol) in THF (100 mL) was added dropwise at
–78 °C a 2.5 solution of nBuLi in hexane (3.51 mL, 8.78 mmol).
After stirring for 10 min, O-phenyl chlorothioformate (1.28 mL,
9.51 mmol) was added and the reaction mixture was warmed up to
20 °C within 12 h. The reaction was quenched by addition of a
saturated aqueous solution of NH4Cl (50 mL), and extracted with
TBME (3 ϫ 30 mL). The combined organic layers were washed
with brine (2ϫ30 mL), dried with MgSO4 and concentrated in
ν = 3064 (br.), 3070 (w), 2934 (s), 2863 (s), 1712 (w), 1612 (m),
˜
1587 (m), 1513 (m), 1463 (m), 1427 (m), 1248 (m), 1112 (s), 1011
(w), 822 (w) cm–1. HRMS (ESI): calcd. for C44H54O3Si2Na [M +
Na+] 709.3504; found 709.3525.
(1S,2S,3S,4aR,6S,7R,8aS)-2,3-Bis(tert-butyldiphenylsilyloxymeth-
yl)-6,7-epoxydecalin-1-ol (8). NaBH4 Reduction: To a solution of
ketone 7 (7.54 g, 10.97 mmol) in a mixture of CH2Cl2/MeOH (1:1)
(100 mL) was added portionwise NaBH4 (1.66 g, 43.90 mmol) at vacuo. The residue was purified by flash chromatography (150 g,
0 °C, and the resulting mixture warmed up to 20 °C within 16 h. A
saturated aqueous solution of NH4Cl (30 mL) was added and the
aqueous phase was extracted with CH2Cl2 (3ϫ20 mL), and the
pentane/TBME, 10:1) to obtain the corresponding thiocarbonate
(5.88 g, 6.99 mmol, 96%) as a colorless solid. Rf = 0.17 (pentane/
ethyl acetate, 15:1). [α]D = +10.91 (c = 2.10, CHCl3, 20 °C). 1H
combined organic phases were washed with saturated aqueous NMR (500 MHz, CDCl3): δ = 0.95 (s, 9 H), 1.03 (s, 9 H), 1.46–
solution of NH4Cl (30 mL) and brine (30 mL), dried with MgSO4
and concentrated in vacuo. The residue was purified by flash
chromatography (150 g, pentane/ethyl acetate, 19:1) to obtain
6.59 g (9.56 mmol, 87%) of the corresponding alcohol as a color-
1.59 (m, 2 H), 1.68–1.77 (m, 3 H), 1.82–2.00 (m, 4 H), 2.76–2.83
(m, 1 H), 3.02–3.05 (m, 1 H), 3.16–3.20 (m, 1 H), 3.35 (dd, J =
10.4, 5.3 Hz, 1 H), 3.45 (dd, J = 10.4, 4.4 Hz, 1 H), 3.53 (dd, J =
9.2, 9.7 Hz, 1 H), 3.84 (dd, J = 10.2, 5.5 Hz, 1 H), 6.04 (m, 1 H),
7.12–7.18 (m, 2 H), 7.20–7.43 (m, 15 H), 7.51 (dd, J = 11.9, 7.9 Hz,
less solid. Rf = 0.57 (pentane/ethyl acetate, 9:1). [α]D = +57.79 (c =
1
3.08, CHCl3, 20 °C). H NMR (300 MHz, CDCl3): δ = 1.13 (s, 9 4 H), 7.65 (dd, J = 20.8, 8.0 Hz, 4 H) ppm. 13C NMR (125 MHz,
H), 1.16 (s, 9 H), 1.79–2.69 (m, 11 H), 3.62 (dd, J = 10.2, 4.9 Hz,
1 H), 3.71 (dd, J = 10.2, 3.0 Hz, 1 H), 3.93 (dd, J = 10.0, 7.5 Hz,
1 H), 4.06 (dd, J = 10.2, 4.3 Hz, 1 H), 4.41 (br., 1 H), 5.84–5.99
(m, 2 H), 7.35–7.53 (m, 12 H), 7.65–7.82 (m, 8 H) ppm. 13C NMR
(75 MHz, CDCl3): δ = 19.3, 19.4, 27.0, 29.3, 29.6, 30.3, 31.1, 35.0,
37.3, 46.3, 64.3, 66.4, 74.8, 125.9, 127.6, 127.7, 128.4, 129.5, 129.6,
CDCl3): δ = 19.3, 19.4, 26.3, 27.0, 27.1, 27.2, 29.6, 33.2, 37.4, 46.2,
50.0, 51.1, 62.5, 66.4, 82.6, 122.6, 126.2, 127.7, 127.8, 129.3, 129.6,
129.7, 133.6, 133.7, 133.8, 133.9, 135.7, 135.8, 135.9, 153.9,
195.2 ppm. IR (KBr): ν = 3428 (br.), 3070 (w), 2928 (m), 2855 (m),
˜
1471 (w), 1427 (m), 1289 (m), 1202 (m) 1112 (s), 1085 (m), 823 (w),
740 (w), 702 (s), 613 (w), 505 (m) cm–1. HRMS (ESI): calcd. for
C51H60O5SSi2Na [M + Na+] 863.3592; found 863.3613. Bu3SnH
Reduction: A solution of the thiocarbonate (1.60 g, 1.90 mmol) in
toluene (50 mL) was degassed at –78 °C. The solution was heated
to 90 °C and nBu3SnH (1.54 mL, 5.71 mmol) and AIBN (cat.) were
added and the mixture was stirred at this temperature for 30 min.
129.7, 133.5, 133.7, 133.9, 135.6, 135.7 ppm. IR (film): ν = 3070
˜
(w), 2957 (m), 2929 (m), 2893 (m), 2856 (m), 1471 (w), 1427 (m),
1112 (s), 823 (m), 740 (m), 702 (s), 505 (m) cm–1. HRMS (ESI):
calcd. for C44H56O3Si2Na [M + Na+] 711.3660; found 711.3664.
Epoxidation: To a solution of the alcohol (6.422 g, 9.32 mmol) in
CH2Cl2 (150 mL) was added mCPBA (70%, 4.59 g, 26.63 mmol) at The solvent was evaporated in vacuo and the residue was purified
–30 °C and the mixture warmed up to 0 °C within 2.5 h. A solution
of Na2SO3 (40 mL) was added and the aqueous phase was ex-
tracted with CH2Cl2 (4ϫ20 mL), the combined organic phases
were washed with NaHCO3 (40 mL) and brine (40 mL), dried with
MgSO4 and concentrated in vacuo. The residue was purified by
flash chromatography (150 g, pentane/ethyl acetate, 9:1 Ǟ 4:1) to
obtain 5.33 g (7.55 mmol, 81%) of the desired α-epoxide 8 as a
colorless solid, and 1.17 g (1.66 mmol, 18%) of the β-epoxide 8Ј as
by flash chromatography (100 g, pentane/ethyl acetate, 10:1) to
yield 1.25 g (18.20 mmol, 96%) of the corresponding epoxide as a
colorless oil. Rf = 0.31 (pentane/ethyl acetate, 19:1). [α]D = +14.13
1
(c = 3.23, CHCl3, 20 °C). H NMR (300 MHz, CDCl3): δ = 1.13
(s, 9 H), 1.14 (s, 9 H), 1.45–1.97 (m, 10 H), 2.00–2.18 (m, 3 H),
3.18–3.24 (m, 1 H), 3.28–3.35 (m, 1 H), 3.54–3.66 (m, 2 H), 3.69–
3.81 (m, 2 H), 7.38–7.53 (m, 12 H), 7.68–7.79 (m, 8 H) ppm. 13C
NMR (75 MHz, CDCl3): δ = 19.4, 24.8, 27.0, 30.4, 30.5, 32.0, 33.6,
34.6, 35.4, 42.4, 52.1, 52.2, 66.5, 66.6, 127.6, 129.5, 129.6, 134.0,
a colorless solid. 8: Rf = 0.22 (pentane/ethyl acetate, 9:1). [α]D
=
1
+12.2 (c = 1.00, CHCl3, 20 °C). H NMR (300 MHz, CDCl3): δ =
134.1, 134.2, 135.6, 135.7, 135.8 ppm. IR (KBr): ν = 3447 (m), 3070
˜
0.89 (s, 9 H), 0.91 (s, 9 H), 1.31–1.48 (m, 2 H), 1.58–1.86 (m, 5 H), (m), 3048 (m), 2929 (s), 1471 (w), 1427 (m), 1390 (w), 1361 (w),
1.90–2.05 (m, 1 H), 2.06–2.23 (m, 2 H), 3.16 (br., 1 H), 3.24–3.36 1111 (br.), 1009 (w), 823 (m), 802 (w), 739 (m), 702 (m), 613 (m),
1996
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