REACTIONS OF 1-IODO- AND 1,3-DIIODOACETONE WITH HYDROGEN SULFIDE
1239
trithiolane IV. After 4 h, the main signals in the 1H and
13C NMR spectra were those typical of trithiolane IV:
δ 1.89 ppm (6H, CH3); δC 31.57 (CH3) and 53.43 ppm
(C). The structure of compounds IV and V was con-
firmed by the IR, H and C NMR, and mass spectra,
which were consistent with published data [3–7].
room temperature. The solution was evaporated under
reduced pressure, and the residue, 3 ml, was subjected
to column chromatography on silica gel using chloro-
form as eluent. Yield 0.5 g (52%), colorless oily sub-
stance. IR spectrum, ν, cm–1: 554 (S–S), 646 (C–S–C)
(cf. [1]). 1H NMR spectrum: δ 1.87 ppm, s (12H, CH3).
13C NMR spectrum, δC, ppm: 31.57 (CH3), 53.43 (C3,
C5). Mass spectrum: m/z 180 [M]+. Found, %: C 39.84;
H 6.13; S 52.85. C6H12S3. Calculated, %: C 40.00;
H 6.66; S 53.33.
1
13
Diiodoacetone Ib reacted with hydrogen sulfide in
a similar way, but the major product was previously
unknown 4,4,7,7-tetramethyl-1,2,3,5,6-pentathiepane
(VI, 59%). Presumably, the key intermediate in this
reaction is propane-2,2-dithiol whose oxidation gives
rise to another intermediate, 3,3,6,6-tetramethyl-1,2,4,5-
tetrathiane (V). Compound V is capable of reacting
with molecular sulfur to produce pentathiepane VI.
The latter could be formed via known insertion of
sulfur into the S–S bond in di- and polysulfides [8, 9].
Apart from pentathiepane VI, from the reactin mixture
we isolated by column chromatography 3,3,5,5-tetra-
methyl-1,2,4-trithiolane (IV, 19%) and 3,3,6,6-tetra-
methyl-1,2,4,5-tetrathiane (V, 10%).
4,4,7,7-Tetramethyl-1,2,3,5,6-pentathiepane (VI)
was obtained in a similar way from 2 g (6.4 mmol) of
1,3-diiodopropan-2-one (Ib). Yield 0.46 g (59%),
yellow thick oily substance. IR spectrum, ν, cm–1: 553
1
(S–S); 486, 525 (S–S–S). H NMR spectrum:
δ 1.91 ppm, s (12H, CH3). 13C NMR spectrum, δC,
ppm: 30.51 (CH3), 66.55 (C4, C7). Mass spectrum:
m/z 244 [M]+. Found, %: C 29.18; H 4.36; S 64.98.
C6H12S5. Calculated, %: C 29.50; H 4.94; S 65.57.
1
The H and 13C NMR spectra were recorded from
The structure of 4,4,7,7-tetramethyl-1,2,3,5,6-pen-
solutions in CDCl3 on a Bruker DPX-400 instrument at
400 and 100 MHz, respectively. The IR spectra were
measured in KBr (or thin films) on an IFS 25 spec-
trometer. The progress of reactions and the purity of
products were monitored by TLC on Silufol UV-254
plates using chloroform as eluent. The products were
isolated by column chromatography on silica gel L
(70–230 mesh) using chloroform as eluent.
1
tathiepane (VI) was confirmed by the IR, H and 13C
NMR, and mass spectra. Absorption bands at 553, 486,
and 525 cm–1 in the IR spectrum of VI can be assigned
to stretching vibrations of the S–S bonds in the di- and
trisulfide fragments of molecule VI. Compound VI
1
displayed in the H NMR spectrum a signal at
δ 1.91 ppm from the methyl protons, while its 13C
NMR spectrum contained signals at δC 30.51 (CH3)
and 76.78 ppm (C4, C7). In the mass spectrum of VI,
the molecular ion peak [M]+ (m/z 244) had fairly high
intensity.
This study was performed under financial support
by the Russian Foundation for Basic Research (project
nos. 05-03-32041, 05-05-64191) and by the Council
for Grants at the President of the Russian Federation
(NSh-4575.2006.3).
The formation of acetone as primary product in the
above reactions was confirmed by independent syn-
thesis of trithiolane IV (72%) by reaction of acetone
with hydrogen sulfide in the presence of iodine
(CHCl3, –30°C).
REFERENCES
1. Voronkov, M.G., Shagun, L.G., and Shagun, V.A., Russ. J.
Org. Chem., 2003, vol. 39. p. 905.
Thus we have shown for the first time that the reac-
tions of mono- and diiodoacetones with hydrogen sul-
fide in chloroform at –30°C begin with the reduction
of the substrate to acetone with hydrogen iodide gen-
erated in situ. Hydrogen iodide then catalyzes nucleo-
philic addition of hydrogen sulfide at the carbonyl
group, leading to trithiolane, tetrathiane, and penta-
thiepane derivatives.
2. Dorofeev, I.A., Shagun, L.G., Mikhailova, I.A., and Vo-
ronkov, M.G., Russ. J. Org. Chem., 2006, vol. 42, p. 1622.
3. NIST/EPA/NIH Mass Spectral Database.
4. Asinger, F., Thiel, M., and Lipfert, G., Justus Liebigs Ann.
Chem., 1959, vol. 627, p. 195.
5. Tjan, S.B., Haakman, J.C., Teunis, C.J., and Peer, H.G.,
Tetrahedron, 1972, vol. 28, p. 3489.
6. Bushweller, C.H., J. Am. Chem. Soc., 1967, vol. 89,
no. 23, p. 5978.
7. Bushweller, C.H., J. Am. Chem. Soc., 1968, vol. 90, no. 9,
p. 2450.
8. Voronkov, M.G., Pereferkovich, A.N., Pestunovich, V.A.,
and Udre, V.E., Zh. Org. Khim., 1967, vol. 3, p. 2211.
9. Safe, S. and Taylor, A., J. Chem. Soc. C, 1970, p. 432.
3,3,5,5-Tetramethyl-1,2,4-trithiolane (IV). Hydro-
gen sulfide was passed through a solution of 2 g
(10.8 mmol) of iodoacetone (Ia) in 10 ml of chloro-
form at –30°C until the initial ketone disappeared
completely (4 h). The mixture was purged with argon
to remove H2S, allowing it to gradually warm up to
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 8 2008
Shagun
