1,1-Dimethoxy-2-cyanocyclopropane (6f). Yield: 0.95 g (75%,
purity 97% by GC). 1H NMR: (400 MHz) d ¼ 1.45–1.50 (m, 2
H, cyclopr. H), 1.73–1.78 (m, 1 H, cyclopr. H), 3.36 and 3.48
(two s, 3 H each, MeO). 13C NMR: (100 MHz) d ¼ 11.06,
20.12, 53.94, 53.97, 90.88, 117.88
each, CH2CH2), 7.30–7.40 (m, 2 H, arom. H), 7.48–7.56 and
7.66–7.74 (two m, 1 H each, arom. H). 13C NMR: (50 MHz)
d ¼ 14.57, 24.83, 110.57, 117.99, 119.77, 124.66, 125.35,
140.33, 150.77, 162.73. Anal. calcd for C10H8N2O: C, 69.76;
H, 4.68; N, 16.27; found: C, 69.60; H, 4.67; N, 16.30%.
1,1-Diethoxy-2-cyanocyclopropane (6g). Yield: 1.24 g (80%,
purity 95% by GC). 1H NMR: (400 MHz) d ¼ 1.20 (t,
J ¼ 7.2 Hz, 3 H, CH3), 1.28 (t, J ¼ 6.8 Hz, 3 H, CH3),
1.47–1.51 (m, 2 H, cyclopr. H), 1.74–1.78 (m, 1 H, cyclopr.
H), 3.65–3.72 and 3.73–3.88 (parts AB of ABX3 , 2 H each,
CH2O). 13C NMR: (100 MHz) d ¼ 11.35, 14.97, 15.10,
20.47, 62.73, 62.97, 89.61, 118.28.
Alkoxycylopropanes 6f,g were transformed into corres-
ponding 3-cyanopropionates 10f,g during attempted purifi-
cation by column chromatography on silica gel (eluent:
hexane/ethyl acetate 1:1).
Reaction of 1-chloro-2-cyanocyclopropene (3) with dienes
7a–c (General procedure). A mixture of nitrile 1 (1.36 g, 10
mmol), the corresponding 1,3-diene 7a,b (30 mmol) or 7c (10
mmol), 2,6-dimethylphenol (0.06 g, 0.5 mmol), TBAHS
(0.035 g, 0.1 mmol) and benzene (5 mL) was stirred vigorously
while 50% aq. NaOH (12 g, 8 mL, 150 mmol) was added drop-
wise during 15 min and cooled in order not to exceed 20 ꢀC.
The reaction mixture was stirred at this temperature for 2 h,
and worked up in the usual way. The residue obtained after
removal of the solvent was purified by column chromato-
graphy on silica gel using a mixture of hexane/ethyl acetate
(gradient).
Methyl 3-cyanopropionate (10f). 1H NMR: (400 MHz)
d ¼ 2.62–2.72 (m, 4 H, CH2CH2), 3.74 (s, 3 H, CH3O). 13C
NMR: (100 MHz) d ¼ 12.91, 29.72, 52.34, 118.39, 170.46.
1-Chloro-6-cyano-3,4-dimethylbicyclo[4.1.0]hept-3-ene (8a).
1
Yield: 0.64 g (35%), m.p. 47–49 ꢀC (MeOH). H NMR: (300
MHz) d ¼ 1.48 and 1.54 (AB, J ¼ 6.2 Hz, cyclopr. H), 1.58
and 1.59 (two s, 6 H together, 2 CH3), 2.41–2.82 (m, 4 H, allyl
CH2). 13C NMR: (50 MHz) d ¼ 18.50, 18.54, 18.98, 22.49,
39.12, 44.27, 120.22, 120.58, 123.05. Anal. calcd for
C10H12ClN: C, 66.12; H, 6.66; N, 7.71; Cl, 19.52; found: C,
65.97; H, 6.57; N, 7.57; Cl, 18.81%.
Ethyl 3-cyanopropionate (10g). 1H NMR: (400 MHz)
d ¼ 1.26 (t, J ¼ 6.8 Hz, 3 H, CH3), 2.61–2.69 (m, 4 H,
CH2CH2), 4.18 (q, J ¼ 6.8 Hz, 2 H, CH2O). 13C NMR: (100
MHz) d ¼ 12.85, 14.02, 29.87, 61.35, 118.45, 169.97.
Cyclic dithioacetals of 2-cyanocyclopropanone 12. The reac-
tion was carried out as described in the general procedure
using dithiol 11a,b (11 mmol).
2-Chloro-4-cyanotricyclo[3.2.1.02,4]oct-6-ene (8b). Yield: 0.51
1
g (31%), oil. H NMR: (200 MHz) d ¼ 1.89 (m, 2 H, cyclopr.
From 11a the mixture of isomeric products 12a and 13a (ca.
1
24:1 by H NMR, 0.74 g, 47%) was obtained, b.p. 96–97 ꢀC/
0.15 Torr.
CH2), 1.96–2.00 and 2.49–2.53 (two m, 1 H each, CH2), 3.10–
3.16 and 3.30–3.36 (two m, 1 H each, allyl CH), 5.96–6.02 and
6.14–6.20 (two m, 1 H each, vinyl CH). 13C NMR: (50 MHz)
d ¼ 21.62, 35.67, 48.85, 52.58, 53.99, 62.06, 119.95, 133.38,
135.26. Anal. calcd for C9H8ClN: C, 65.30; H, 4.87; N, 8.46;
Cl, 21.41; found: C, 65.51; H, 4.79; N, 8.46; Cl, 21.09%.
2-Cyano-4,7-dithiaspiro[2,4]heptane (12a). 1H NMR: (400
MHz) d ¼ 1.75 (dd, J ¼ 6.4 Hz, J ¼ 6.8 Hz, 1 H, cyclopr.
H), 1.84 (dd, J ¼ 6.8 Hz, J ¼ 9.6 Hz, 1 H, cyclopr. H), 1.91
(dd, J ¼ 6.4 Hz, J ¼ 9.6 Hz, 1 H, cyclopr. H), 3.40–3.51 (m,
4 H, dithiolane H). 13C NMR: (100 MHz) d ¼ 17.39, 17.93,
39.52, 39.57, 42.65, 118.05. Slow Kugelrohr distillation (b.p.
100 ꢀC/0.15 Torr) increased the content of 13a in the mixture
2-Chloro-4-cyano-1,5-diphenyl-8-oxabenzotricyclo[3,2,1,02,4]-
oct-6-ene (8c). Yield: 1.11 g (30%), m.p. 137–138 ꢀC. 1H NMR:
(200 MHz) d ¼ 2.39 and 3.07 (two d, J ¼ 6.8 Hz, 1H each,
cyclopr. CH2), 7.30–7.40, 7.48–7.55 and 7.72–7.80 (m, 14 H
together, arom. H). 13C NMR: (50 MHz) d ¼ 31.02, 32.02,
58.06, 88.61, 90.64, 117.25, 121.36, 122.96, 127.27, 127.64,
127.97, 128.45, 128.72, 128.85, 129.56, 129.60, 131.80, 132.71,
145.97, 146.23. Anal. calcd for C24H16ClNO: C, 77.94; H,
4.36; N, 3.79; Cl, 9.58; found C, 77.70; H, 4.32; N, 3.74; Cl,
8.99%.
1
(up to 25%, determined by H NMR). This allowed to assign
individual resonance signals for 13a.
2-(2-Cyanoethylidene)-1,3-dithiolane (13a). 1H NMR: (200
MHz) d ¼ 3.11 (d, J ¼ 7.2 Hz, 2 H, CH2CN), 3.28–3.38 (m,
4 H, dithiolane H), 5.36 (t, J ¼ 7.2 Hz, =CH). 13C NMR:
(50 MHz) d ¼ 20.17, 37.51, 38.33, 42.59, 101.86, 117.07,
143.75. Anal. calcd for C6H7NS2 : C, 45.82; H, 4.50; N, 8.91;
for the mixture of 12a/13a (3:1) found: C, 45.90; H, 4.50; N,
9.02%.
References
2-Cyano-4,8-dithiaspiro[2,5]octane (12b). From 11b, 12b
(0.89 g, 52%) was obtained, b.p. 102 ꢀC/0.05 Torr. 1H
NMR: (400 MHz) d ¼ 1.57–1.67 (m, 2 H, cyclopr. H), 2.02–
2.06 (m, 1 H, cyclopr. H), 1.90–2.03 (m, 1H), 2.19–2.27 (m,
1H), 2.79–2.86 (m, 2 H), 3.01–3.08 (m, 1 H) and 3.13–3.20
(m, 1 H, all dithiane H). 13C NMR: (100 MHz) d ¼ 19.10,
23.93, 24.61, 29.78, 30.54, 31.79, 117.98. Anal. calcd for
C7H9NS2 : C, 49.08; H, 5.31; N, 8.18; found C, 49.17; H,
5.26; N, 8.19%.
1
(a) R. R. Kostikov, A. P. Molchanov and H. Hopf, Top. Curr.
Chem., 1990, 155, 60; (b) M. G. Banwell and M. E. Reum,
Advances in Strain in Organic Chemistry, JAI Press Ltd, London,
1991, vol. 1, p. 36; (c) for a review on substitution of one or two
groups attached to a cyclopropane ring, see: L. K. Sydnes, in
Methods in Organic Chemistry (Houben-Weyl), ed. A. De Meijere,
Georg Thieme Verlag, Stuttgart, New York, 1997, vol. E 17b,
p. 1255.
´
M. Fedorynski, A. Dybowska and A. Jonczyk, Synthesis, 1988,
549.
(a) E. V. Dehmlow and S. S. Dehmlow, Phase Transfer Catalysis,
3rd edn., Verlag Chemie, Weinheim, 1993; (b) C. M. Starks, C. L.
Liotta and M. Halpern, Phase-Transfer Catalysis, Chapman &
Hall, New York, London, 1994; (c) M. Ma˛kosza and M.
´
2
3
2-(2-Cyanoethyl)benzoxazole (14). The reaction was carried
out as described in the general procedure, using 2-aminophe-
nol (2.4 g, 22 mmol). The residue obtained after concentration
of the benzene solution was passed through silica gel to remove
tars. This allowed the crude product to be obtained (0.3 g,
17%, purity by GC > 92%). Analytical sample was obtained
´
Fedorynski, in Handbook of Phase Transfer Catalysis, eds. Y.
Sasson and R. Neumann, Blackie Academic & Professional,
London, 1977, p. 135.
E. V. Dehmlow and J. Wilkenloh, Chem. Ber., 1990, 123, 583.
´
M. Fedorynski, W. Ziołkowska and A. Jonczyk, J. Org. Chem.,
1993, 58, 6120.
4
5
1
by sublimation in vacuo (80 ꢀC/0.1 Torr), m.p. 86–88 ꢀC. H
´
´
NMR: (200 MHz) d ¼ 2.94–3.02 and 3.28–3.36 (two m, 2 H
298
New J. Chem., 2003, 27, 295–299