12498 J. Am. Chem. Soc., Vol. 120, No. 48, 1998
Magnus et al.
NMR (CDCl3) δ 180.6, 148.7, 104.1, 53.0, 41.9, 38.7, 29.4, 20.8, 18.0,
14.2, 12.6. HRMS (CI) calcd for C18H34NSiO2 324.236, found 324.235.
3-((E)-3-Phenylpropenoylamino)-1-triisopropylsilyl(oxy)-cyclo-
hexan-1-ene (90). A solution of 83 (1.88 g, 7.00 mmol) and Et3N (1.50
mL, 10.50 mmol) in THF (40 mL) was treated at -78 °C with
cinnamoyl chloride (1.290 g, 7.70 mmol) in THF (4 mL). After
completion of the reaction (5 min), the cold bath was removed and the
solution partitioned between Et2O (30 mL) and saturated aqueous
NaHCO3 (30 mL). The aqueous phase was extracted with Et2O (2 ×
15 mL). The extracts were combined, washed with water (2 × 10 mL),
and dried (MgSO4). Concentration in vacuo afforded an oil which
crystallized from n-pentane to give 90 (2.480 g, 89%) as a white
42.5, 35.4, 29.3, 21.1, 18.0, 12.5. HRMS (MH+) calcd for C24H37N2-
SiO4 445.252, found 445.251. 94 (40 mg, 9%). IR (CHCl3) 3421, 3023,
2946, 2867, 1692 cm-1. 1H NMR (CDCl3) δ 8.12 (2H, d, J ) 8.6 Hz),
7.36 (2H, d, J ) 8.6 Hz) 5.52 (1H, b), 4.21-4.17 (1H, m), 3.85 (1H,
d, J ) 7.2 Hz), 3.42-3.36 (1H, m), 2.85-2.78 (1H, m), 2.0-1.0 (6H,
m), 0.95-0.80 (21H, m). 13C NMR (CDCl3) δ 178.9, 146.5, 145.7,
129.4, 122.9, 77.1, 52.6, 51.8, 41.6, 40.0, 36.3, 28.4, 18.0, 16.7, 13.1.
HRMS (MH+) calcd for C24H37N2SiO4 445.252, found 445.251.
1,3,3a,6,7,7a-hexahydro-3-benzyl-2H-indol-2,4-dione (95). To a
solution of 92 (50 mg, 0.125 mmol) in THF (5 mL) at -78 °C was
added n-Bu4NF (0.13 µL, 1.0 M in Et2O). The solution was warmed
to 25 °C and after 20 min the solution was evaporated in vacuo and
the residue purified by chromatography over silica gel eluting with
EtOAc to give 95 (27 mg, 90%): mp 119-121 °C (Et2O). IR (neat)
powder: mp 152-153 °C. IR (neat) 3267, 1654 cm-1 1H NMR
.
(CDCl3) δ 7.59 (1H, d, J ) 15.6 Hz), 7.47 (2H, m), 7.33 (3H, m), 6.34
(1H, d, J ) 15.6 Hz), 5.57 (1H, d, J ) 8.1 Hz), 4.86 (1H, d, J ) 4.3
Hz), 4.70 (1H, m), 2.07 (2H, t, J ) 5.5 Hz), 1.5-1.9 (4H, m), 0.9-1.2
(21H, m). 13C NMR (CDCl3) δ 164.8, 155.2, 140.8, 134.9, 129.5, 128.7,
127.7, 121.1, 104.0, 45.0, 29.8, 29.0, 19.5, 17.9, 12.6. HRMS (CI) calcd
for C24H37NSiO2 399.259, found 399.260.
1
3251, 1695 cm-1. H NMR (CDCl3) δ 7.99 (1H, s), 7.29 (2H, d, J )
7.2 Hz), 7.15 (2H, m), 7.07 (1H, d, J ) 7.3 Hz), 3.73 (1H, dd, J )
14.0, 9.8 Hz), 3.43 (1H, dd, J ) 14.0, 5.1 Hz), 3.20 (1H, dt, J ) 5.1,
4.2 Hz), 2.48 (1H, m), 2.15 (1H, t, J ) 6.6 Hz), 1.88 (1H, dt, J )
13.8, 4.6 Hz), 1.4-1.7 (2H, m), 1.2-1.4 (1H, m), 1.0-1.2 (21H, m).
13C NMR (CDCl3) δ 210.3, 178.3, 139.8, 129.1, 128.3, 126.2, 55.0,
49.7, 47.8, 41.3, 32.0, 27.9, 20.2. HRMS (MH+) calcd for C15H18NO2
244.134, found 244.135.
3-[(E)-3-(4-Nitrophenyl)-propenoylamino]-1-triisopropylsilyl-
(oxy)-cyclohexan-1-ene (91). A solution of 4-nitrocinnamoyl chloride
(1.164 g, 5.50 mmol) in THF (10 mL) was added to 83 (1.348 g, 5.00
mmol) and Et3N (1.050 mL, 7.50 mmol) in THF (25 mL) at -78 °C.
After the reaction was complete, the cold bath was removed, and the
solution was partitioned between CH2Cl2 (80 mL) and saturated aqueous
NaHCO3 (40 mL). The aqueous layer was extracted with CH2Cl2 (2 ×
10 mL). The organic phase was washed with brine (40 mL), and water
(20 mL) and dried (MgSO4). Concentration in vacuo gave 91 (2.124
g, 96%): mp 62 °C. IR (neat) 3261, 2943, 1657 cm-1. 1H NMR (CDCl3)
δ 8.19 (2H, d, J ) 8.7 Hz), 7.63 (1H, d, J ) 15.9 Hz), 7.61 (2H, d, J
) 8.2 Hz), 6.47 (1H, d, J ) 15.6 Hz), 5.69 (1H, d, J ) 8.0 Hz), 4.85
(1H, d, J ) 4.1 Hz), 4.69 (1H, m), 2.07 (1H, t, J ) 5.5 Hz), 1.5-1.9
(4H, m), 0.9-1.2 (21H, m). 13C NMR (CDCl3) δ 163.7, 155.4, 148.0,
141.2, 138.0, 128.2, 125.3, 124.0, 103.6, 45.3, 29.7, 28.9, 19.4, 17.9,
12.5. HRMS (MH+) calcd for C24H37N2SiO4 445.252, found 445.252.
3-Benzyl-4-triisopropylsilyl(oxy)-1,3,3a,6,7,7a-hexahydro-2H-in-
dol-2-one (92). A solution of 90 (0.40 g, 1.0 mmol) in dry 1,2-
dichlorobenzene (40 mL) was treated at 0 °C with Me3Al (0.550 mL,
1.10 mmol, 2.0 M solution in toluene). The ice bath was removed and
the solution warmed to 25 °C and then heated to reflux under argon.
After 20 h the mixture was cooled to 0 °C and quenched with saturated
aqueous NaHCO3 (1 mL) and concentrated under high vacuum at 50
°C. The residue was dissolved in CH2Cl2 (100 mL), washed with
saturated aqueous NaHCO3 (2 × 15 mL) and water (10 mL), and dried
(Na2SO4). Flash chromatography over silica gel eluting with EtOAc
6-Azido-1,3,3a,6,7,7a-hexahydro-3-benzyl-4-triisopropylsilyl(oxy)-
2H-indol-2-one (96). Iodosobenzene (660 mg, 3 mmol, 3.0 equiv) was
added to a solution of 92 (400 mg, 1 mmol) in CH2Cl2 (20 mL) at
-20 °C, and trimethylsilylazide 95% (728 mg, 0.84 mL, 6 mmol, 6
equiv) was added via syringe. The cooling bath was removed and the
reaction temperature allowed to warm to 25 °C. After 1 h the clear
yellow solution was concentrated under reduced pressure (first at the
rotaevaporator, then in a Kugelrohr at high vacuum at 70 °C) to give
an oily residue (663 mg). Chromatography over Florisil eluting with
EtOAc/hexanes (1:2) followed by pentane washing of the resulting solid
gave 96 (266.5 mg, 60.5%): mp 147-148 °C (MeCN). IR (CHCl3)
2094, 1692, 1649 cm-1. 1H NMR (300 MHz, CDCl3) 7.28-7.16 (5H,
m), 5.74 (1H, br), 5.26 (1H, d, J ) 5.9 Hz), 4.16 (1H, m), 3.97 (1H,
m), 3.29 (1H, t, J ) 8.8 Hz), 3.14 (1H, d,d, J ) 3.5, 13.6 Hz), 2.87
(1H, dt, J ) 3.6, 9.3 Hz), 2.74 (1H, dd, J ) 13.6, 9.2 Hz), 1.96 (1H,
d, J ) 13.5 Hz), 1.4-1.0 (22H, m). 13C NMR (CDCl3) 178.2, 154.1,
139.5, 129.4, 128.2, 126.4, 102.5, 55.7, 48.8, 44.3, 42.5, 35.1, 34.8,
18.1, 18.0, 12.5. HRMS (MH+) calcd for C24H37N4O2Si 441.269, found
441.268.
(E)-3-(Carboethoxy)-propenoylamino-1-triisopropylsilyl(oxy)-cy-
clohexan-1-ene 97. A solution of fumaric acid monoethyl ester (0.303
g, 2.10 mmol) and N-methylmorpholine (0.250 mL, 2.28 mmol) in THF
(50 mL) was treated with isobutylchloroformate (0.275 mL, 2.10 mmol)
at 0 °C. After 15 min at 0 °C, 83 (0.472 g, 1.75 mmol) in THF (10
mL) was added. The ice bath was removed after 15 min, and the mixture
was dissolved in Et2O (60 mL), washed with saturated aqueous NaHCO3
(2 × 15 mL), and dried (Na2SO4). Chromatography over silica gel
eluting with EtOAc gave 97 (0.666 g, 96%) as a white powder: mp
gave 92 (0.292 g, 73%): mp 156 °C. IR (neat) 3223, 1698, 1664 cm-1
.
1H NMR (CDCl3) δ 7.82 (1H, s), 7.55 (2H, d, J ) 7.3 Hz), 7.0-7.2
(3H, m), 4.92 (1H, dd, J ) 4.5, 2.9 Hz), 3.27 (1H, dd, J ) 14.2, 3.6
Hz), 3.12 (1H, m), 3.00 (1H, dd, J ) 14.2, 8.5 Hz), 2.86 (1H, td, J )
8.8, 3.7 Hz), 2.76 (1H, t, J ) 8.3 Hz), 1.7-1.9 (1H, m), 1.6-1.7 (1H,
m), 1.3-1.5 (1H, m), 0.9-1.2 (22H, m). 13C NMR (CDCl3) δ 170.8,
148.2, 140.6, 129.2, 128.0, 125.9, 105.2, 52.7, 44.9, 42.7, 35.5, 29.2,
21.2, 18.1, 12.6. HRMS (MH+) calcd for C24H38NSiO2 400.267, found
400.268.
1
99-100 °C. IR (neat) 1726, 1661, 1634 cm-1. H NMR (CDCl3) δ
6.97 (1H, d, J ) 15.4 Hz), 6.75 (1H, d, J ) 15.4 Hz), 6.45 (1H, d, J
) 8.2 Hz), 4.77 (1H, d, J ) 4.1 Hz), 4.60 (1H, m), 4.15 (2H, q, J )
7.1 Hz), 2.00 (2H, t, J ) 6.3 Hz), 1.4-1.8 (4H, m), 1.23 (3H, t, J )
7.1 Hz), 0.8-1.2 (21H, m). 13C NMR (CDCl3) δ 165.8, 162.5, 155.1,
137.1, 129.7, 103.3, 61.0, 45.1, 29.7, 28.7, 19.3, 17.8, 14.0, 12.4. HRMS
(CI) calcd for C21H37NSiO4 395.249, found 395.249.
3-(4-Nitrobenzyl)-4-triisopropylsilyl(oxy)-1,3,3a,6,7,7a-hexahydro-
2H-indol-2-one (93) and 8-(4-Nitrophenyl)-5-aza-10-triisopropylsi-
lyl(oxy)-tricyclo[4.4.0.03,10]-decan-4-one (94). A solution of 91 (0.444
g, 1.00 mmol) in toluene (45 mL) was treated at 0 °C with Me3Al
(0.550 mL, 1.10 mmol, 2.0 M solution in toluene). The solution was
heated to reflux under argon. After 22 h the mixture was cooled to 0
°C and quenched with water (0.5 mL), partitioned between Et2O (200
mL) and saturated aqueous Rochelle’s salt solution (100 mL). The
organic phase was washed with a 50% saturated aqueous NaHCO3 (50
mL), dried (Na2SO4), and concentrated in vacuo. Flash chromatography
over silica gel eluting with EtOAc gave 93 (0.326 g, 74%): mp 146-
148 °C. IR (CHCl3) 3430, 1694, 1665 cm-1. 1H NMR (CDCl3) δ 8.09
(2H, d, J ) 8.6 Hz), 7.41 (2H, d, J ) 8.6 Hz), 6.47 (1H, s), 5.10 (1H,
t, J ) 3.7 Hz), 3.71 (1H, m), 3.23 (1H, dd, J ) 13.4, 3.0 Hz), 3.16
(1H, t, J ) 8.0 Hz), 2.82 (1H, m), 2.80 (1H, qd, J ) 13.4, 3.6 Hz),
1.95-2.20 (2H, m), 1.80-1.95 (1H, m), 0.60-1.40 (22H, m). 13C NMR
(CDCl3) δ 178.3, 148.7, 147.9, 146.4, 129.9, 123.4, 105.7, 52.8, 44.6,
3-Carboethoxymethyl-4-triisopropylsilyl(oxy)-1,3,3a,6,7,7a-hexahy-
dro-2H-indol-2-one (98) and 8-Carboethoxy-5-aza-10-triisopropyl-
silyl(oxy)-tricyclo[4.4.0.03,10]-decan-4-one (99). A solution of 97 (0.079
g, 0.20 mmol) in 1,2-dichloroethane (8 mL) was treated with Me3Al
(0.200 mL, 0.40 mmol, 2.0 M solution in toluene) at 0 °C. The solution
was heated to reflux under argon until completion of the reaction (3
h). The mixture was cooled to 0 °C and quenched with water (0.5 mL).
The crude mixture was dissolved in CH2Cl2 (20 mL), washed with
saturated aqueous NaHCO3 (2 × 5 mL), and dried (Na2SO4). After
concentration in vacuo the residue was purified by flash chromatography
over silica gel eluting with EtOAc to give 98 (0.040 g, 51%) and 99
(0.019 g, 24%). For 98: mp 100-102 °C. IR (neat) 1734, 1700, 1684,
1
1668, 1653 cm-1. H NMR (CDCl3) δ 6.19 (1H, s), 5.00 (1H, t, J )
4.4 Hz), 4.0-4.2 (2H, m), 3.92 (1H, dt, J ) 6.0, 5.1 Hz), 3.21 (1H, dt,