PHOTOCHEMICAL REACTION OF ACYL IODIDES WITH ALKENES AND THIOPHENE
1211
I
I
hν
hν
hν
+
2MeCOI
MeCO
COMe
MeCO
COMe
1/n MeCO
COMe
_I
S
S
2
S
S
n
The photochemical reaction of MeCOI with the
studied olefins is the simplest method of preparation of
the above mentioned iodine-containing unsaturated
compounds. 6-Iodohex-1-ene and 7-iodohept-1-ene
were previously synthesized by a more laborious
procedure in the course of preparation of female sex
pheromones [5, 6]. Their synthesis was underlain by
the previous formation of tosylates of the
corresponding 6- and 7-hydroxy-substituted alkenes
followed by the cleavage of the obtained esters with
sodium iodide.
was distilled in a vacuum. Yield 6.7 g (60%), bp 82°С
20
(20 mm Hg), n 1.4900 (bp 90–100°С (40 mm Hg),
D
2
0
1
nD 1.4902 [6]). Н NMR spectrum, δ, ppm: 1.38–1.45
m (4Н), 1.75–1.90 m (2H), 2.11 m (2H), 2.02–2.10 m
3
(2H), 3.19 t (2H, J 6.8 Hz), 4.92–5.05 m (2H,
1
3
CH=CH ), 5.74–5.8 m (1H, CH =CH). С NMR
2
2
spectrum, δ, ppm: 7.40 (IСН ), 29.32 (IСН CH ), 29.34
2
2
2
(IСН CH CH ), 28.90 (IСН CH CH CH ), 33.69
2
2
2
2
2
2
2
(IСН СН СН CH CH ), 114.80 (H C=CH), 138.30
2
2
2
2
2
2
(H C=CH).
2
Dibenzoyl. а. A mixture of 7 g (0.03 mol) of
benzoyl iodide and 2.52 g (0.03 mol) of 1-hexene was
subjected to UV irradiation for 29 h. The liberated
iodine was sublimated in a vacuum. Yield 7.1 g (89%),
Unlike the reactions with the alkenes under
investigation the photochemical reaction of acetyl
iodide with thiophene resulted in polymer formation.
The process is accompanied with elemental iodine
liberation. Analogous polymer was obtained at the
low-temperature (–15°С) reaction of the same reagents
but without UV irradiation [1]. This finding suggests
that the reactions occur by identic mechanisms. This
includes the MeCOI addition to both thiophene double
bonds with subsequent iodine elimination and the
polymerization of the formed diacetodihydrothiophene.
–
1
mp 95–97°С [7]. IR spectrum, ν, cm : 3413, 3378,
1
679, 1595, 1449, 1068, 755, 701.
b. A mixture of 11.6 g (0.05 mol) of benzoyl iodide
and 4.9 g (0.05 mol) of 1-heptene was subjected to UV
irradiation for 29 h and worked up as in procedure а.
Yield 6.8 g (65%).
3-Iodocyclohexene. A mixture of 8.5 g (0.05 mol)
of acetyl iodide and 4.1 g (0.05 mol) of cyclohexene
was subjected to UV irradiation for 29 h and then
6
-Iodohex-1-ene. а. A mixture of 8.5 g (0.05 mol)
of acetyl iodide and 4.2 g (0.05 mol) of hex-1-ene was
subjected to UV irradiation for 29 h. Then the mixture
was distilled in a vacuum. Yield 6.01 g (57%) bp 78–
distilled in a vacuum. Yield 7.06 g (67%), bp 78–79°С
1
(
30 mm Hg), (bp 80°С (30 mm Hg), [8]). Н NMR
3
2
0
spectrum, δ, ppm: 1.23, 1.43 d (4Н, J 7.2, 6.75 Hz),
1.72, 2.16 d (4H, J 6.7, 7.8 Hz), 1.90, 2.37 d (4H, J
1.7, 7.8 Hz), 3.7 s (1H, J 4.1, 7.2 Hz), 5.58 s (1H, J
7
9°С (30 mm Hg), n 1.5100 (bp 84–85°С (40 mm Hg),
D
3
3
2
0
1
nD 1.5121 [5]). Н NMR spectrum, δ, ppm: 1.31 m
3
3
3
(
2
4Н, IСН CH CH ), 1.85 q (2H, IСН CH , J 7.0 Hz),
2 2 2 2 2
3
13
3
1.6 Hz), 5.72 s (1H, J 4.03 Hz). С NMR spectrum,
δ, ppm: 24.2 (ICH), 25.6 (ICHCH CH ), 26.7
.11 q (2H, CH =CHCH , J 6.3, 6.8 Hz), 3.21 t (2H,
2 2
IСН , J 7.0 Hz), 4.92 d.d (1H, HCH=CH, J 1.8, 10.3 Hz),
.99 d.d (1H, HCH=CH, J 1.8, 17.0 Hz), 5.79 m (1H,
CH =CH). С NMR spectrum, δ, ppm: 7.15 (IСН2),
3
3
2
2
2
3
(ICH CH CH CH ), 40.8 (ICHCH ), 126.9 (HC=CH),
2 2 2 2 2
4
1
3
129.2 (HC=CH).
2
2
9.93 (IСН CH ), 29.61 (IСН CH CH ), 31.82 (IСН ·
2 2 2 2 2 2
Dibenzoyl. A mixture of 11.6 g (0.05 mol) of
benzoyl iodide and 4.1 g (0.05 mol) of cyclohexene
was subjected to UV irradiation for 29 h. After
sublimation of iodine from the reaction mixture in a
vacuum 8.1 g (77% of dibenzoyl was isolated [7].
CH CH CH ), 114.55 (H C=CH), 138.26 (H C=CH).
Found, %: С 33.98; H 5.73; I 59.91. C H I. Calcu-
lated, %: С 34.3; H 5.27; I 60.41.
2
2
2
2
2
6
11
b. A mixture of 8.5 g (0.05 mol) of acetyl iodide
and 4.2 g (0.05 mol) of 1-hexene was subjected to UV
irradiation for 50 h, and then distilled in a vacuum.
Reaction of acetyl iodide with thiophene. A
mixture of 3.4 g (0.02 mol) of acetyl iodide and 1.68 g
2
0
Yield 5.89 g (56%), bp 78–79°С (30 mm Hg), nD
.5100 [5].
-Iodohept-1-ene. A mixture of 8.5 g (0.05 mol) of
(
0.02 mol) of thiophene was subjected to UV
1
irradiation for several minutes. Vigorous reaction was
observed with the formation of a polymer product.
Polymer was washed with chloroform and dried in a
6
acetyl iodide and 4.9 g (0.05 mol) of 1-heptene was
subjected to UV irradiation for 29 h. Then the mixture
–
1
vacuum. IR spectrum, ν, cm : 3095, 2922, 1707,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 50 No. 8 2014