7326 J . Org. Chem., Vol. 66, No. 22, 2001
Cardarelli et al.
acrylonitrile (2 mmol), xanthone (2 mmol) in 20 mL of benzene
(irradiation wavelength 366 nm). After purification on column,
96 mg (35% yield) of 3bj was isolated.
and 910 mg of benzophenone (5 mmol) in 33 mL of benzene
was irradiated for 20 h. The raw photolyzate was purified by
column chromatography (cyclohexane/ethyl acetate 99.2:0.8).
The product was further purified by alumina chromatography
(pentane/ethyl acetate from 99:1 to 60:40) yielding 295 mg of
3bk (39% yield) as an oil and 45 mg of cyclohexyldiphenyl-
methanol (8b).
3bj: 1H (CDCl3) δ 0.9-1.8 (m, 13H), 2.27 (t, 2H, J ) 7.6
Hz). 13C (CDCl3) δ 14.5 (CH2), 25.8 (2 CH2), 26.2 (CH2), 32.4
(2 CH2), 32.5 (CH2), 36.4 (CH), 119.9 (CN). IR, (neat) ν/cm-1
2924, 2849, 2243, 1490, 1447. MS (m/z) 138 (100), 121 (40), 95
(25), 82 (90). Anal. Calcd for C9H15N: C, 78.78; H, 11.02; N,
10.21. Found: C, 78.65; H, 11.09; N, 10.18.
3bk : 1H (CDCl3) δ 0.8-1.4 (m, 6H), 1.1 (d, 3H, J ) 7 Hz),
1.6-1.85 (m, 6H), 2.2-2.4 (m, 2H, AB part of an ABX system).
13C (CDCl3) δ 16.5 (CH3), 22.1 (CH2), 26.2 (CH2), 26.3 (2 CH2),
28.9 (CH2), 30.2 (CH2), 35.6 (CH), 41.5 (CH), 119.4 (CN). IR,
(neat) ν/cm-1 2923, 2852, 2243. Anal. Calcd for C10H17N: C,
79.41; H, 11.33; N, 9.26. Found: C, 79.38; H, 11.30; N, 9.24.
8b: 1H (CDCl3) δ 1.0-1.5 (m, 5H), 1.6-1.9 (m, 5H), 2.1 (bs,
1H), 2.5 (m, 1H), 7.2 (m, 2H), 7.3 (m, 4H), 7.6 (m, 4H). 13C
(CDCl3) δ 26.9 (CH2), 27.1 (CH2), 27.7 (CH2), 46.1 (CH), 80.8,
126.2 (CH), 126.7 (CH), 128.5 (CH), 146.8. IR, (neat) ν/cm-1
3497, 3055, 2924, 1597. Anal. Calcd for C19H22O: C, 85.67; H,
8.32. Found: C, 85.60; H, 8.30.
Attem p ted Alk yla tion of Alk en es 1l a n d 1m . A solution
of 1.7 mL of cyclohexane (16.3 mmol), nitrile 1l (or 1m ) (0.3
mmol), and 55 mg of benzophenone (0.3 mmol) in 3.3 mL of
benzene was irradiated for 2 days. After this period, GC
analysis showed a small consumption of the starting nitriles
and no formation of alkylation products.
3-Cycloh ep tylp r op ion itr ile (3cj). A solution of 6 mL of
cycloheptane (55.6 mmol), 330 µL of acrylonitrile (5 mmol),
and 910 mg of benzophenone (5 mmol) in 50 mL of benzene
was irradiated for 15 h. Chromatography (cyclohexane/ethyl
acetate 99.5:0.5) gave 3cj (377 mg, 50% yield) as an oil.
This synthesis (same irradiation time) was also carried out
under the following conditions: cycloheptane (248 mmol),
acrylonitrile (6 mmol), xanthone (6 mmol) in 30 mL of benzene
(irradiation wavelength 366 nm). After purification by means
bulb to bulb distillation, 450 mg (49.5% yield) of 3cj was
isolated.
3cj: 1H (CDCl3) δ 1.0-1.8 (m, 15H), 2.35 (t, 2H, J ) 7.6
Hz). 13C (CDCl3) δ 15.5 (CH2), 26.5 (2 CH2), 28.7 (2 CH2),
33.5 (CH2), 34.1 (2 CH2), 46.3 (CH), 120.4 (CN). IR, (neat)
ν/cm-1 2925; 2852; 2242; 1447. MS (m/z) 152 (70, M+1), 135
(26), 100 (47), 97 (28), 82 (100), 55 (54). Anal. Calcd for
C
10H17N: C, 79.41; H, 11.33; N, 9.26. Found: C, 79.35; H,
(1-Cycloh exylcycloh exyl)m a lon on itr ile (4bn ). A solu-
tion of 16.6 mL of cyclohexane (90 mmol), 440 mg of 1n (3
mmol), and 550 mg of benzophenone (3 mmol) in 30 mL of
benzene was irradiated for 19 h. Extraction with pentane and
chromatography (cyclohexane/ethyl acetate 98:2) gave 455 mg
of 4bn (66% yield) as a syrup.
11.19; N, 9.20.
3-Cyclod od ecylp r op ion itr ile (3d j). A solution of 11.6 g
of cyclododecane (69 mmol), 465 µL of acrylonitrile (7 mmol),
and 1.27 g of benzophenone (7 mmol) in 70 mL of benzene was
irradiated for 15 h. Chromatography (from neat cyclohexane
to cyclohexane/ethyl acetate 97:3) gave 460 mg of 3d j (50%
yield) as a colorless solid. A small portion was crystallized from
benzene/methanol (mp 193-194 °C).
4bn : 1H (CDCl3) δ 1.0-2.0 (m, 21H), 4.0 (s, 1H). 13C (CDCl3)
δ 21.2 (CH2), 25.0 (CH2), 26.2 (CH2), 27.0 (CH2), 27.3 (CH2),
28.8 (CH), 30.5 (CH2), 43.1, 43.3 (CH), 112.6 (CN). IR, (neat)
ν/cm-1 2930, 2247, 1453. MS (m/z) 230 (1), 121 (28), 83 (100),
55 (45). Anal. Calcd for C15H22N2: C, 78.21; H, 9.63; N, 12.16.
Found: C, 78.12; H, 9.68; N, 12.12.
(1-Cycloh ep tylcycloh exyl)m a lon on itr ile (4cn ). A solu-
tion of 3.6 mL of cycloheptane (33.4 mmol), 440 mg of 1n (3
mmol), and 550 mg of benzophenone (3 mmol) in 30 mL of
benzene was irradiated for 40 h. Extraction with pentane and
chromatography (cyclohexane/ethyl acetate 99:1) gave 590 mg
of 4cn (80% yield) as a syrup.
3d j: 1H (DMSO) δ 0.9-1.5 (m, 25H); 2.4 (t, 2H, J ) 7.5
Hz). 13C (DMSO) δ 12.2 (CH2); 24.9 (2 CH2);27.2 (2 CH2); 27.5
(2 CH2); 27.6 (CH2); 28.2 (2 CH2); 31.8 (2 CH2); 33.6 (CH2);
36.7 (CH); 124.7 (CN). IR, (KBr) ν/cm-1 2938; 2868; 2242; 1470;
1446. Anal. Calcd for C15H27N: C, 81.38; H, 12.29; N, 6.33.
Found: C, 81.44; H, 12.23; N, 6.37.
3-(1-Ad a m a n tyl)p r op ion itr ile (3ej). A solution of 1.36 g
of adamantane (10 mmol), 330 µL of acrylonitrile (5 mmol),
and 911 mg of benzophenone (5 mmol) in 50 mL of benzene
was irradiated for 20 h. The final product was isolated by
means of repeated column chromatography. In the first run,
neat cyclohexane was used as eluant in order to eliminate
excess adamantane and the second (cyclohexane/ethyl acetate
99:1) allowed to isolate 3ej (251 mg, 26.6% yield) as a syrup.
The 2-adamantyl isomer (3′ej, 16% of the corresponding
1-isomer) was only detected by GC-MS technique.
4cn : 1H (CDCl3) δ 1.25-2.0 (m, 23H), 4.0 (s, 1H). 13C
(CDCl3) δ 21.2 (CH2), 25.0 (CH2), 27.5 (CH2), 27.6 (CH2), 28.2
(CH2), 28.8 (CH), 30.5 (CH2), 43.3 (CH), 44.1, 112.6 (CN). IR,
(neat) ν/cm-1 2926, 2247, 1459. Anal. Calcd for C16H24N2: C,
78.64; H, 9.90; N, 11.46. Found: C, 78.62; H, 9.88; N, 11.49.
(1-Cyclod od ecyl-cycloh exyl)m a lon on itr ile (4d n ). A so-
lution of 2.45 g of cyclododecane (14.5 mmol), 215 mg of 1n
(1.5 mmol), and 275 mg of benzophenone (1.5 mmol) in 15 mL
of benzene was irradiated for 36 h. Chromatography (cyclo-
hexane/ethyl acetate 99:1) gave 182 mg of 4d n (39.5% yield)
as a syrup.
3ej: 1H (CDCl3) δ 1.3-1.95 (m, 17H), 2.30 (t, 2H, J ) 7.5
Hz). 13C (CDCl3) δ 10.8 (CH2); 28.19; 28.2 (3 CH); 36.7 (4 CH2);
39.2 (CH2); 41.4 (2 CH2); 120.7 (CN). IR, (neat) ν/cm-1 2907;
2849; 2247. MS (m/z) 190 (13), 135 (100), 93 (15), 79 (21). Anal.
Calcd for C13H19N: C, 82.48; H, 10.12; N, 7.40. Found: C,
82.44; H, 10.10; N, 7.40.
4d n : 1H (CDCl3) δ 1.1-1.9 (m, 33H), 4.1 (s, 1H). 13C (CDCl3)
δ 21.9 (CH2), 23.9 (CH2), 24.2 (CH2), 24.8 (CH2), 25.4 (CH2),
25.9 (CH2), 26.9 (CH2), 29.3 (CH), 31.3 (CH2), 41.1 (CH), 45.0,
113.1 (CN). IR, (neat) ν/cm-1 2933, 2246, 1445. Anal. Calcd
for C21H34N2: C, 80.20; H, 10.90; N, 8.91. Found: C, 80.30; H,
10.83; N, 8.79.
3′ej: MS (m/z) 189 (62), 146 (40), 135 (74), 107 (45), 93 (62),
91 (63), 79 (100), 67 (68), 41 (59).
3-Cyclop en tylbu tyr on itr ile (3a k ). A solution of 8.5 mL
of cyclopentane (90 mmol), 407 µL of crotonitrile (5 mmol), and
910 mg of benzophenone (5 mmol) in 45 mL of benzene was
irradiated for 16 h. The raw photolyzate was purified by
column chromatography (cyclohexane/ethyl acetate 99:1). The
product was further purified by alumina chromatography
(pentane/ ethyl acetate 99:1) yielding 150 mg of 3a k (22%
yield) as an oil.
P h otoch em ica l Alk yla tion of 1o w ith Cycloh exa n e. A
solution of 16 mL of cyclohexane (148 mmol), 435 µL of 1o (3
mmol), and 550 mg of benzophenone (3 mmol) in 30 mL of
benzene was irradiated for 15 h at 360 nm. Purification by
column chromatography (cyclohexane/ethyl acetate 99:1) yielded
44 mg of 7b, 76 mg of (1-cyclohexyl-1-methyl-pent-4-enyl)-
malononitrile 5 (11% yield) and an impure fraction which was
further purified on column to give pure (2S,5S)-2-cyclohexyl-
2,5-dimethyl-cyclopentane-1,1-dicarbonitrile 6 (192 mg, 28%
yield). The stereochemistry of diastereoisomer 6 was proven
with NOE experiments; thus, the irradiation of 2-methyl
hydrogens at 1.2 ppm caused an enhancement of the H-5 signal
(3%) in the corresponding 1D-NOE difference spectrum. This
correlation was further confirmed by 2D-NOESY experiment.
3a k : 1H (CDCl3) δ 1.1 (d, 3H, J ) 7 Hz), 1.15 (m, 2H), 1.5-
1.75 (m, 7H), 1.75-1.9 (m, 2H), 2.25 (dd, 1H, J ) 7 and 16.5
Hz), 2.4 (dd, 1H, J ) 4.5 and 16.5 Hz). 13C (CDCl3) δ 18.8 (CH3),
24.3 (CH2), 25.6 (CH2), 25.7 (CH2), 30.9 (CH2), 31.3 (CH2), 36.4
(CH), 45.8 (CH), 119.5 (CN). IR, (neat) ν/cm-1 2957, 2870, 2238.
Anal. Calcd for C9H15N: C, 78.78; H, 11.02; N, 10.21. Found:
C, 78.70; H, 10.91; N, 10.23.
3-Cycloh exylbu tyr on itr ile (3bk ). A solution of 17.6 mL
of cyclohexane (163 mmol), 407 µL of crotonitrile (5 mmol),
1
7b: H (CDCl3) δ 0.8-1.9 (m, 11H), 7.3 (m, 5H).60