A. K. Mohanakrishnan et al. / Tetrahedron 62 (2006) 3242–3247
3245
4
1
.2.2. 2-Bromo-2-(2-allyl)-3-(4-trimethylsilyl-3-butynyl)-
-cyclohexanone 2b. Following the general procedure,
and 0.10 (9H, 2s, SiMe ); d (100 MHz, CDCl ) 205.6,
3 C 3
204.9, 108.3, 107.4, 86.3, 85.7, 65.3, 64.9, 62.4, 61.2, 57.6,
53.4, 49.4, 42.2, 37.8, 30.3, 29.3, 27.8, 24.4, 22.9, 19.6,
19.1, 18.1, 17.4, 0.13, 0.08; MS (EI) m/z 361 [MK15] ,
compound 2b was obtained as a pale yellow liquid in 58%
yield; (Found: C, 56.42; H, 7.29. C H BrOSi requires C,
C
1
6 25
5
7
6.30; H, 7.38%); IR (liquid) nmax: 2171, 1712, 1610, 845,
59 cm ; dH (400 MHz, CDCl ) 5.71–5.66 (1H, m,
(23), 347 (10), 235 (20), 221 (12), 127 (35), 82 (100%).
K1
3
CH CH]CH ), 5.20–5.08 (2H, m, CH CH]CH ), 3.32
2
4.2.6. 2-Iodo-2-(2-allyl)-3-(4-trimethylsilyl-3-butynyl)-1-
cycloheptanone 2e. Following the general procedure,
2
2
2
(
1H, dd, JZ5.6, 5.6 Hz, CHCH]CH ), 3.18 (1H, m,
2
CH CHCH ), 2.78 (1H, dd, JZ8.4, 8.4 Hz, CHCH]CH ),
compound 2e was obtained as a pale yellow liquid in 53%
yield; IR (liquid) nmax: 2174, 1704, 1610, 842, 760 cm
d (300 MHz, CDCl ) 5.86–5.76 (1H, m, CH CH]CH ),
H 3 2 2
2
2
2
K1
2
CH ), 1.68–1.51 (4H, m, CH CH CH ), 0.15 and 0.12 (9H,
.42–2.21 (2H, m, CH CH ), 2.02–1.89 (4H, m, CH CH -
;
2
2
2
2
2
2
2
2
2
1
4
2
s, SiMe ); d (100 MHz, CDCl ) 203.2, 202.9, 133.4,
3
5.08–4.96 (2H, m, CH CH]CH ), 3.30 (1H, dt, JZ2.4,
C
3
2 2
32.3, 119.8, 119.3, 107.1, 106.1, 76.71, 75.0, 46.4, 43.3,
1.1, 39.9, 37.1, 36.6, 29.8, 27.7, 26.5, 25.9, 24.4, 24.2,
2.0, 19.4, 17.9, 17.3, 0.16, 0.07; MS (EI) m/z (%): 342
11.4 Hz, CHCH]CH ), 3.09 (1H, dd, JZ6.1, 14.4 Hz,
2
CH CHCH ), 2.72 (1H, dd, JZ7.8, 14.1 Hz,
2
2
CHCH]CH ), 2.58–2.34 (3H, m, CH CHCH ), 2.28–2.08
(3H, m, CH CHCH ), 1.94–1.72 (2H, m, CH CH CH ),
2 2 2 2 2
2
2
2
C
C
[MC2] , (15%), 340 (M , 15), 308 (12), 261 (78), 170
(65), 129 (82), 73 (100).
1.58–1.26 (4H, m, CH CH CH ), 0.13 and 0.10 (9H, 2s,
2 2 2
SiMe ); d (75 MHz, CDCl ) 205.8, 136.8, 117.4, 105.7,
3
C
3
4
3
.2.3. 2-Bromo-2-(2-allyl)-3-methyl-3-(4-trimethylsilyl-
-butynyl)-1-cyclohexanone 2c. Following the general
86.0, 64.9, 42.1, 37.9, 30.4, 30.3, 27.3, 18.3, 0.16, 0.09;
H27IOSi requires
C
HRMS (EI): M found 402.0867. C17
402.0876.
procedure, compound 2c was obtained as a pale yellow
liquid in 56% yield; (Found: C, 57.56; H, 7.74. C H -
BrOSi requires C, 57.45; H, 7.66%); IR (liquid) nmax: 2173,
1
5
1
7 27
4.2.7. 2-Iodo-2-(2,3-butadienyl)-3-(4-trimethylsilyl-3-
butynyl)-1-cyclohexanone 2f. Following the general
procedure, compound 2f was obtained as a pale yellow
K1
712, 1613, 848, 762 cm ; d (400 MHz, CDCl ) 5.58–
H 3
.52 (1H, m, CH CH]CH ), 5.09–5.00 (2H, m, CH -
2
2
2
CH]CH ), 3.89 (1H, d, JZ15.0 Hz, CHCH]CH ), 2.41
liquid in 55% yield; IR (liquid) nmax: 2174, 1950, 1704,
1610, 842, 760 cm ; dH (300 MHz, CDCl ) 5.02–4.97
2
2
K1
(
CH CH CH ), 1.96–1.60 (4H, m, CH CH CH ), 1.32–1.19
1H, dd, JZ8.3, 5.4 Hz, CHCH]CH ), 2.39–2.07 (2H, m,
2
3
(1H, m, CH]C]CH ), 4.68–4.63 (2H, m, CH]C]CH ),
2
2
2
2
2
2
2
2
(
4H, m, CH CH CH ), 1.01 and 0.77 (3H, 2s, Me), 0.13 and
2
3.48–3.36 (2H, m, CH CH]C]CH ), 2.89–2.80 (1H, m,
2 2
2
2
0
1
5
2
.11 (9H, 2s, SiMe ); d (100 MHz, CDCl ) 204.6, 203.1,
3
CH CHCH ), 2.38–2.15 (4H, m, CH CH CH ), 1.98–1.82
2 2 2 2 2
(2H, m, CH CH CH ), 1.55–1.31 (4H, m, CH CH CH ),
2 2 2 2 2 2
3
C
32.1, 131.9, 118.5, 118.0, 107.8, 107.1, 84.3, 84.1, 61.3,
8.3, 45.1, 38.9, 38.5, 37.4, 37.3, 36.4, 33.7, 31.4, 31.2,
5.0, 21.8, 21.6, 19.4, 17.7, 15.0, 14.4, 0.16, 0.07; MS (EI)
0.12 and 0.06 (9H, 2s, SiMe ); d (75 MHz, CDCl ) 209.3,
3
C
3
203.5, 125.1, 106.0, 87.1, 85.5, 75.2, 43.5, 38.9, 35.8, 32.6,
27.5, 24.3, 17.2, 0.16, 0.09; HRMS (EI): M found
C
C
C
m/z 356 [MC2] , (18), 354 (M , 18), 341 (14), 278 (23),
53 (65), 190 (35), 116 (76), 82 (100%).
2
400.0711. C H IOSi requires 400.0719.
17 27
4.2.4. 2-Iodo-2-(2-allyl)-3-methyl-3-(4-trimethylsilyl-3-
butynyl)-1-cyclohexanone 2c . Following the general
4.2.8. 2-Iodo-2-(2-allyl)-3-(4-trimethylsilyl-3-butynyl)-1-
cyclopentanone 2g. Following the general procedure,
compound 2g was obtained as a pale yellow liquid in 58%
0
procedure, compound 2c was obtained as a pale yellow
0
liquid in 60% yield; (Found: C, 50.87; H, 6.68. C H IOSi
yield; (Found: C, 48.27; H, 6.25. C H IOSi requires C,
15 23
1
7
27
requires C, 50.74; H, 6.76%); IR (liquid) nmax: 2175, 1710,
1
48.13; H, 6.19%); IR (liquid) nmax: 2174, 1704, 1610, 842,
760 cm ; dH (300 MHz, CDCl ) 5.64–5.57 (1H, m,
K1
610, 844, 760 cm ; dH (400 MHz, CDCl ) 5.78–5.66
K1
3
3
(
1H, m, CH CH]CH ), 5.46–5.32 (2H, m, CH CH]CH ),
2
CH CH]CH ), 5.12–5.02 (2H, m, CH CH]CH ), 3.08
2
2
2
2
2
2
2
4
8
.08 (1H, d, JZ13.5 Hz, CHCH]CH ), 2.58 (1H, dd, JZ
(1H, dd, JZ6.7, 14.5 Hz, CHCH]CH ), 2.67 (1H, dd, JZ
2
2
.4, 5.6 Hz, CHCH]CH ), 2.48–2.16 (2H, m, CH CH -
7.8, 13.8 Hz, CH CHCH ), 2.43 (1H, dd, JZ7.8, 17.3 Hz,
2
2
2
2
2
CH ), 2.03–1.68 (4H, m, CH CH CH ), 1.43–1.24 (4H, m,
2
CHCH]CH ), 2.38–2.15 (2H, m, CH CH ), 2.14–2.03
(1H, m, CH CH), 1.98–1.82 (2H, m, CH CH ), 1.47–1.33
2 2 2
2
2
2
2 2 2
CH CH CH ), 1.16 and 0.98 (3H, 2s, Me), 0.13 and 0.11
2
2
2
(
9H, 2s, SiMe ); d (100 MHz, CDCl ) 204.7, 203.4, 132.2,
3
(2H, m, CH CH ), 0.89–0.82 (1H, m, CHCH ), 0.14 and
2 2 2
C
3
1
4
2
31.9, 118.4, 118.1, 108.0, 107.3, 84.5, 84.1, 62.8, 59.3,
6.2, 39.2, 38.6, 37.9, 37.4, 36.8, 33.8, 32.5, 32.2, 25.6,
2.4, 21.3, 19.9, 17.3, 15.7, 15.5, 0.19, 0.09; MS (EI)
0.07 (9H, 2s, SiMe ); d (75 MHz, CDCl ) 210.9, 133.9,
3 C 3
119.8, 107.1, 85.6, 63.7, 43.9, 42.8, 34.3, 34.2, 25.2, 16.9,
0.14, 0.08; MS (EI) m/z 374 (M , 15), 247 (100), 206 (43),
148 (23%).
C
C
m/z 402 (M , 13), 277 (31), 261 (6), 234 (4), 127 (95),
2 (100%).
8
4.3. Representative procedure for iodination of indole
5a–10
4
.2.5. 2-Iodo-3-methyl-3-(4-trimethylsilyl-3-butynyl)-1-
cycloheptanone 2d. Following the general procedure,
compound 2d was obtained as a pale yellow liquid in 63%
yield; (Found: C, 48.05; H, 6.77. C H IOSi requires C,
4.3.1. 1-Phenylsulfonyl-3-iodoindole 5a. To a solution of
FeCl3 (1.39 g, 8.5 mmol) in acetonitrile (20 mL), NaI
(0.64 g, 4.3 mmol) was added and stirred at 0 8C for
15 min. To this, indole 3 (0.5 g, 4.3 mmol) was added and
the stirring was continued for an additional 6 h. The reaction
1
5 25
4
7.87; H, 6.70%); IR (liquid) nmax: 2173, 1706, 840,
K1
58 cm ; dH (400 MHz, CDCl ) 4.33 and 4.24 (1H, 2s,
7
COCHI), 2.47–2.23 (3H, m, CH CHCH ), 2.16–2.03 (3H,
3
2
2
m, CH CHCH ), 1.86–1.71 (2H, m, CH CH CH ), 1.69–
2
mixture was then poured into saturated NH Cl solution,
4
2
2
2
2
1
.24 (4H, m, CH CH CH ), 0.96 and 0.89 (3H, 2s, Me), 0.14
2
extracted with ethyl acetate (2!20 mL). The organic layer
2
2