bp 135 ЊC at 2.0 mmHg (Found: Mϩ, 160.0634. C9H8N2O
CH2CH3), 3.93 (1 H, dd, J 7 and 3, 7-H) and 5.02 (1 H, s, 1-H);
requires M, 160.0637); νmax(film)/cmϪ1 2238 (C᎐N) and 1610
δC(EX) 15.1 and 25.3 (2 q, 2 CH3), 26.9, 36.7 and 43.6 (3 t, C-3,
-4 and -6), 65.6 (t, CH2CH3), 81.6 (s, C-5), 81.8 and 83.6 (2 d,
C-1 and -7), 83.1 [s, C(CN)2], 110.3 and 110.8 (2 s, 2 CN) and
176.4 (s, C-2); m/z 232 (Mϩ, 6%), 160 (100), 145 (10) and 43 (11).
(1R*,5S*,7R*)-7-Ethoxy-5-methyl-8-oxabicyclo[3.2.1]octan-
2-ylidenemalononitrile (1R*,5S*,7R*)-15b, an oil (Found: Mϩ,
232.1203. C13H16N2O2 requires M, 232.1212); νmax(CHCl3)/cmϪ1
᎐
᎐
(C᎐C); δ (EX) 1.48–1.88, 2.04–2.20 and 2.25–2.33 (6 H, 3 m, 3
᎐
H
CH2), 3.75 (1 H, s, 5Ј-H) and 7.23 (1 H, s, 3-H); δC(EX) 19.3,
27.5 and 28.8 (3 t, 3 CH2), 64.9 (s, C-1Ј), 68.6 (d, C-5Ј), 89.2 (s,
C-2), 110.5 and 112.3 (2 s, 2 CN) and 163.3 (d, C-3); m/z 160
(Mϩ, 33%), 131 (56), 104 (45) and 55 (100).
(trans)-2,3-Epoxy-1-ethylbutylidenemalononitrile 6, bp
105 ЊC at 0.5 mmHg (Found: Mϩ, 162.0794. C9H10N2O requires
2225 (C᎐N) and 1600 (C᎐C); δ (EX) 1.16 (3 H, t, J 6.9,
᎐
᎐
᎐
H
M, 162.0793); νmax(film)/cmϪ1 2225 (C᎐N) and 1590 (C᎐C);
CH2CH3), 1.35 (3 H, s, 5-CH3), 1.84–2.00 (3 H, m, 4-H2 and
6-H), 2.21 (1 H, ddd, J 13.5, 10.2 and 1.0, 6-H), 2.92–2.98 (2 H,
m, 3-H2), 3.44 and 3.52 (2 H, each dq, J 9.2 and 6.9, CH2CH3),
4.40 (1 H, ddd, J 10.2, 6.6 and 4.0, 7-H) and 5.10 (1 H, d, J 6.6,
1-H); δC(EX) 15.3 and 26.0 (2 q, 2 CH3), 27.3, 37.8 and 41.0 (3 t,
C-3, -4 and -6), 66.9 (t, CH2CH3), 78.6 and 80.7 (2 d, C-1 and
-7), 80.7 (s, C-5), 84.7 [s, C(CN)2], 110.9 and 111.1 (2 s, 2 CN)
and 177.9 (s, C-2); m/z 232 (Mϩ, 6%), 160 (100), 145 (10) and 43
(12).
᎐
᎐
᎐
δH(EX) 1.20 (3 H, t, J 7.6, CH2CH3), 1.50 (3 H, d, J 5.0, 4-H3),
2.22 and 2.51 (2 H, each dq, J 12.5 and 7.6, CH2CH3), 3.15 (1
H, qd, J 5.0 and 1.7, 3-H) and 3.68 (1 H, d, J 1.7, 2-H); δC(EX)
13.2 and 17.5 (2q, 2 CH3), 24.8 (t, CH2), 56.6 and 57.7 (2 d, C-2
and -3), 86.2 [s, C(CN)2], 110.9 and 111.1 (2 s, 2 CN) and 181.9
(s, C-1); m/z 162 (Mϩ, 83%), 147 (100), 119 (56) and 107 (36).
Photoreaction of the dinitrile 2 and EVE
A solution of 2 (265 mg, 1.81 mmol) in dry acetonitrile (35 cm3)
with EVE (13.1 g, 182 mmol) was irradiated with a low-pressure
mercury lamp in a quartz test tube (conversion 95%) for 6 h at
0 ЊC. After removal of the solvent, flash chromatography [SiO2
A; CH2Cl2–hexane (2:1→5:1)] to afford the exo-adduct 14a
(133 mg, 36%), endo-adduct 14b (28.6 mg, 8%) and intractable
material (mainly polymers).
8-Ethoxy-9-oxabicyclo[4.2.1]nonan-2-ylidenemalononitrile
16, an oil (Found: Mϩ, 232.1216. C13H16N2O2 requires M,
232.1212); νmax(film)/cmϪ1 2234 (C᎐N) and 1592 (C᎐C); δ (EX)
᎐
᎐
᎐
H
1.21 (3 H, t, J 7.3, CH3), 1.59–1.67 and 1.82–2.04 (5 H, 2 m,
4-H2, 5-H2 and 7-H), 2.52 (1 H, dt, J 13.5 and 9, 7-H), 2.57–2.72
(1 H, m, 3-H), 2.96–3.07 (1 H, m with d-character, J 15, 3-H),
3.52 and 3.61 (2 H, each dq, J 9.2 and 7.3, CH2CH3), 4.45 (1 H,
td, J 9 and 3, 8-H), 4.65–4.71 (1 H, m, 6-H) and 5.21 (1 H, d,
J 9, 1-H); δC(EX) 15.1 (q, CH3), 20.8, 35.0, 35.6 and 35.7 (4 t,
C-3, -4, -5 and -7), 67.2 (t, CH2CH3), 80.3, 81.0 and 82.3 (3 d,
C-1, -6 and -8), 84.1 [s, C(CN)2], 111.7 and 111.8 (2 s, 2 CN) and
187.1 (s, C-2); m/z 232 (Mϩ, 78%), 203 (37), 175 (34) and 160
(100).
(1R*,5S*,7S*)-7-Ethoxy-8-oxabicyclo[3.2.1]octan-2-ylidene-
malononitrile (1R*,5S*,7S*)-14a, an oil (Found: Mϩ, 218.1054.
C12H14N2O2 requires M, 218.1055); νmax(film)/cmϪ1 2236 (C᎐N)
᎐
᎐
and 1604 (C᎐C); δ (EX) 1.24 (3 H, t, J 6.9, CH ), 1.66–1.74,
᎐
H
3
2.05–2.18, 2.21–2.26, 2.34–2.48 and 2.90–2.98 (6 H, 5 m, 3-H2,
4-H2 and 6-H2), 3.47 and 3.57 (2 H, each dq, J 8.9 and 6.9,
CH2CH3), 3.93–3.97 (1 H, m, 7-H), 4.74 (1 H, br s, 5-H) and
5.03 (1 H, s, 1-H); δC(EX) 15.1 (q, CH3), 25.6, 30.7 and 37.4 (3 t,
C-3, -4 and -6), 65.8 (t, CH2CH3), 75.0 (d, C-5), 80.9 (d, C-1),
82.7 (d, C-7), 83.4 [s, C(CN)2], 110.2 and 110.7 (2 s, 2 CN) and
176.5 (s, C-2); m/z 218 (Mϩ, 22%), 146 (100), 118 (28) and 91
(32).
2-Cyano-3-(7Ј-ethoxy-8Ј-oxabicyclo[3.2.1]octanyl)acrylo-
nitrile 17, an oil (Found: Mϩ, 232.1215. C13H16N2O2 requires
M, 232.1212); νmax(film)/cmϪ1 2250 (C᎐N) and 1620 (C᎐C);
᎐
᎐
᎐
δH(EX) 1.18 (3 H, t, J 6.9, CH3), 1.23–1.36 and 1.53–1.82 (6 H,
2 m, 3 CH2), 2.10–2.15 (2 H, m, 6Ј-H2), 3.34 and 3.54 (2 H, each
dq, J 8.9 and 6.9, CH2CH3), 4.18 (1 H, dd, J 6 and 4, 7Ј-H),
4.65–4.67 (1 H, m, 5Ј-H) and 7.25 (1 H, s, 3-H); δC(EX) 15.0
(q, CH3), 16.8, 28.5 and 32.8 (3 t, C-2Ј, -3Ј and -4Ј), 38.1 (t,
C-6Ј), 64.8 (t, CH2CH3), 75.8 (d, C-5Ј), 82.7 (d, C-7Ј), 86.1
and 88.5 (2 s, C-2 and -1Ј), 111.2 and 112.8 (2 s, 2 CN) and
167.3 (d, C-3); m/z 232 (Mϩ, 36%), 160 (100), 134 (38), 121
(57) and 55 (43).
(4R*,6S*)-4-Ethoxy-10-oxabicyclo[4.3.1]dec-1-ene-3,3-
dicarbonitrile (4R*,6S*)-18, an oil (Found: Mϩ, 232.1205.
C13H16N2O2 requires M, 232.1212); δH(EX) 1.30 (3 H, t, J 6.9,
CH3), 1.53–1.59, 1.89–2.06, 2.08–2.19 and 2.25–2.32 (7 H, 4 m,
5-H, 7-, 8- and 9-H2), 2.40 (1 H, dt, J 14.8 and 10, 5-H), 3.73
and 3.87 (2 H, each dq, J 9.2 and 6.9, CH2CH3), 4.36 (1 H, dd,
J 10 and 2, 4-H), 4.47–4.55 (1 H, m, 6-H) and 5.23 (1 H, d,
J 1.0, 2-H); δC(EX) 15.0 (q, CH3), 25.0, 26.7, 30.3 and 32.4 (4 t,
C-5, -7, -8 and -9), 40.4 (s, C-3), 67.6 (t, CH2CH3), 77.9 and 80.4
(2 d, C-4 and -6), 104.5 (d, C-2), 114.1 and 115.5 (2 s, 2 CN) and
161.7 (s, C-1); m/z 232 (Mϩ, 23%), 160 (100), 134 (46), 121 (81)
and 55 (51).
(1R*,5S*,7R*)-7-Ethoxy-8-oxabicyclo[3.2.1]octan-2-ylidene-
malononitrile (1R*,5S*,7R*)-14b, an oil (Found: Mϩ,
218.1057. C12H14N2O2 requires M, 218.1055); νmax(film)/cmϪ1
᎐
᎐
2236 (C᎐N), 2218 (C᎐N) and 1609 (C᎐C); δ (EX) 1.17 (3 H, t,
᎐
᎐
᎐
H
J 6.9, CH3), 1.73 (1 H, ddd, J 13.5, 4.0 and 1.0, 6-H), 1.80–1.87,
2.11–2.24 and 2.91–2.97 (4 H, 3 m, 3-H2 and 4-H2), 2.58 (1 H,
ddd, J 13.5, 10.2 and 7.6, 6-H), 3.46 and 3.55 (2 H, each dq,
J 9.2 and 6.9, CH2CH3), 4.37 (1 H, ddd, J 10.2, 6.6 and 4.0,
7-H), 4.46–4.50 (1 H, m, 5-H) and 5.08 (1 H, d, J 6.6, 1-H);
δC(EX) 15.3 (q, CH3), 25.9 and 31.8 (2 t, C-3 and -4), 34.8 (t,
C-6), 67.1 (t, CH2CH3), 74.7 (d, C-5), 77.5 (d, C-1), 80.4 (d,
C-7), 84.8 [s, C(CN)2], 110.9 and 111.0 (2 s, 2 CN) and 178.0 (s,
C-2); m/z 218 (Mϩ, 32%), 146 (100), 118 (21) and 91 (26).
Analytical irradiation of 2 containing varying amounts of EVE
Aliquots of a 0.035 mol cmϪ3 solution of 2 in acetonitrile con-
taining EVE (3.5, 2.63, 1.75, 1.05, 0.35, 0.175 and 0.105 mol
cmϪ3) were irradiated in quartz test-tubes under argon for 4 h at
0 ЊC. Yields and conversions were determined by GLC analysis
using octadecane as an internal standard. The results are shown
in Table 1.
(2ЈR*,3ЈS*,5ЈS*)-2-Cyano-3-(3Ј-ethoxy-5Ј-methyltetra-
hydrofuran-2Ј-yl)pent-2-enenitrile (2ЈR*,3ЈS*,5ЈS*)-19a, an oil
(Found: Mϩ, 234.1372. C13H18N2O2 requires M, 234.1368);
νmax(CHCl3)/cmϪ1 2225 (C᎐N) and 1595 (C᎐C); δ (EX) 1.22 (3
᎐
᎐
᎐
H
Photoreaction of the dinitriles 3–6 and EVE
H, t, J 7, OCH2CH3), 1.25 (3 H, t, J 8, 5-H3), 1.37 (3 H, d, J 6,
5Ј-CH3), 1.67 (1 H, ddd, J 13.2, 9.9 and 6.9, 4Ј-H), 2.15 (1 H,
ddd, J 13.2, 6 and 2, 4Ј-H), 2.53 and 2.57 (2 H, each dq, J 12.5
and 8, 4-H2), 3.46 and 3.53 (2 H, each dq, J 8.9 and 7,
OCH2CH2), 3.85 (1 H, ddd, J 6.9, 4.3 and 2, 3Ј-H), 4.30 (1 H, m
with d-quintet-character, J 9.9 and 6, 5Ј-H) and 4.67 (1 H, d,
J 4.3, 2Ј-H); δC(EX) 13.1, 15.3 and 19.4 (3 q, 3 CH3), 27.2 and
40.5 (2 t, C-4 and -4Ј), 65.7 (t, OCH2CH3), 76.7, 85.6 and 85.8 (3
d, C-2Ј, -3Ј and -5Ј), 85.0 (s, C-2), 111.2 and 111.9 (2 s, 2 CN)
and 183.7 (s, C-3); m/z 234 (Mϩ, 3%), 192 (58), 136 (58), 99
(100) and 85 (45).
By analogy with the photolysis of 2, the dinitriles 3, 4, 5 and 6
were irradiated with 10 equiv. EVE, affording the correspond-
ing adducts. The results are summarized in Table 2.
(1R*,5S*,7S*)-7-Ethoxy-5-methyl-8-oxabicyclo[3.2.1]octan-
2-ylidenemalononitrile (1R*,5S*,7S*)-15a, bp 140 ЊC at 0.2
mmHg (Found: Mϩ, 232.1207. C13H16N2O2 requires M,
232.1212); νmax(film)/cmϪ1 2220 (C᎐N) and 1595 (C᎐C); δ (EX)
᎐
᎐
᎐
H
1.23 (3 H, t, J 6.9, CH2CH3), 1.47 (3 H, s, 5-CH3), 1.73–1.95 and
2.35–2.52 (5 H, 2 m, 3-H, 4-H2 and 6-H2), 2.96 (1 H, ddt, J 17.5,
6.3 and 1.7, 3-H), 3.44 and 3.55 (2 H, each dq, J 8.9 and 6.9,
J. Chem. Soc., Perkin Trans. 1, 1998
317