1242
B. C. Ranu, T. Mandal
LETTER
(3) (a) Ranu, B. C.; Hajra, A.; Jana, U. J. Org. Chem. 2000, 65,
6270. (b) Ranu, B. C.; Hajra, A.; Jana, U. Tetrahedron Lett.
2000, 41, 531. (c) Ranu, B. C.; Samanta, S.; Hajra, A.
Synlett 2002, 987. (d) Ranu, B. C.; Das, A.; Samanta, S.
Synlett 2002, 727. (e) Ranu, B. C.; Dey, S. S.; Hajra, A.
Tetrahedron 2002, 58, 2529. (f) Ranu, B. C.; Hajra, A.;
Dey, S. S.; Jana, U. Tetrahedron 2003, 59, 813. (g) Ranu,
B. C.; Samanta, S. J. Org. Chem. 2003, 68, 7130. (h) Ranu,
B. C.; Das, A.; Hajra, A. Synthesis 2003, 1012. (i) Ranu, B.
C.; Samanta, S. Tetrahedron 2003, 59, 7901.
(4) (a) Ohno, H.; Hamaguchi, H.; Tanaka, T. Org. Lett. 2000, 2,
2161. (b) Barros, O. S. d. R.; Lang, S.; Oliveira, C. A. F. d.;
Peppe, C.; Zeni, G. Tetrahedron Lett. 2002, 43, 7921.
(c) Barros, O. S. d. R.; Lang, E. S.; Peppe, C.; Zeni, G.
Synlett 2003, 1725. (d) Miyabe, H.; Yamaoka, Y.; Naito, T.;
Takemoto, Y. J. Org. Chem. 2004, 69, 1415.
few selective representative compounds are provided here.
Entry 8: IR (neat): 1475, 1716 cm–1. 1H NMR (300 MHz,
CDCl3): d = 1.27 (d, J = 6.51 Hz, 3 H), 2.12 (s, 3 H), 2.55
(dd, J1 = 8.34 Hz, J2 = 17.22 Hz, 1 H), 2.72 (dd, J1 = 5.31 Hz,
J2 = 17.19 Hz, 1 H), 3.65 (m, 1 H), 7.26 (d, J = 8.61 Hz, 2
H), 7.33 (d, J = 8.61 Hz, 2 H). 13C NMR (75 MHz): d = 20.9,
30.5, 38.4, 50.0, 129.0 (2 × C), 132.5, 133.4, 133.6 (2 × C),
206.2. Anal. Calcd for C11H13OClS: C, 57.76; H, 5.73.
Found: C, 57.84; H, 5.81.
Entry 17: IR (neat): 1477, 1724 cm–1. 1H NMR (300 MHz,
CDCl3): d = 1.33 (d, J = 6.75 Hz, 3 H), 2.55–2.61 (m, 2 H),
3.13–3.19 (m, 1 H), 3.78 (s, 2 H), 7.24–7.33 (m, 5 H), 9.66
(s, 1 H). 13C NMR (75 MHz): d = 21.3, 33.6, 35.2, 50.1,
127.1, 128.5 (2 × C), 128.7 (2 × C), 137.9, 200.5. Anal.
Calcd for C11H14OS: C, 68.0; H, 7.26. Found: C, 68.09; H,
7.17.
(5) Ranu, B. C.; Mandal, T.; Samanta, S. Org. Lett. 2003, 5,
1439.
Entry 20: Obtained as a mixture of diastereoisomers (59:41).
IR (neat): 1475, 1724, 2721 cm–1. 1H NMR (300 MHz,
CDCl3): d = 1.04 (t, J = 7.17 Hz, 3 H), 1.20 (d, J = 7.21 Hz,
3 H), 1.62–1.73 (m, 2 H), 2.63–2.67 (m, 1 H), 3.34–3.40 (m,
1 H), 7.26 (d, J = 8.34 Hz, 2 H), 7.37 (d, J = 8.34 Hz, 2 H),
9.67 (d, J = 1.59 Hz, 1 H, minor), 9.68 (d, J = 0.98 Hz, 1 H,
major). 13C NMR (75 MHz): d = 9.7 (major), 10.2 (minor),
12.1 (major), 11.8 (minor), 26.2 (major), 24.2 (minor), 48.9
(major), 49.6 (minor), 52.9 (major), 51.7 (minor), 129.1 (2 ×
C), 133.4, 133.5 (2 × C), 133.6, 203.2. Anal. Calcd for
C12H15OClS: C, 59.37; H, 6.23. Found: C, 59.41; H, 6.17.
Entry 24: IR (neat): 1477, 1737 cm–1. 1H NMR (300 MHz,
CDCl3): d = 2.59 (t, J = 7.5 Hz, 2 H), 3.13 (t, J = 7.5 Hz, 2
H), 3.67 (s, 3 H), 7.19–7.29 (m, 4 H). 13C NMR (75 MHz):
d = 29.7, 34.4, 52.3, 129.5 (2 × C), 131.8 (2 × C), 134.1,
134.2, 172.4. Anal. Calcd for C10H11O2ClS: C, 52.06; H,
4.77. Found: C, 52.11; H, 4.71.
(6) General Experimental Procedure; Representative
Example for the Cleavage of Diphenyl Disulfide and
Subsequent Reaction with Methyl Vinyl Ketone (Entry
2): Indium(I) iodide (121 mg, 0.5 mmol) was added to the
solution of diphenyl disulfide (109 mg, 0.5 mmol) in freshly
distilled THF (2.5 mL) under argon atmosphere followed by
the addition of methyl vinyl ketone (70 mg, 1 mmol). The
reaction mixture was heated under reflux for 2.5 h (TLC).
THF was then evaporated off and the residue was quenched
with water and extracted with Et2O (3 × 10 mL). The Et2O
extract was washed with water and dried (Na2SO4). The
aqueous extract containing indium derivatives was discarded
although in relatively large-scale reactions indium salts may
be recovered. Evaporation of the solvent left the crude
product, which was purified by column chromatography
over silica gel (hexane–Et2O, 95:5) to provide the pure
addition product, 4-thiophenylbutan-2-one (155 mg, 86%)
as a colorless liquid. IR (neat): 1716, 1477 cm–1. 1H NMR
(300 MHz, CDCl3): d = 2.14 (s, 3 H), 2.76 (t, J = 7.26 Hz, 2
H), 3.13 (t, J = 7.26 Hz, 2 H), 7.20–7.22 (m, 2 H), 7.26–7.35
(m, 3 H). 13C NMR (75 MHz, CDCl3): d = 27.9, 30.5, 43.5,
126.7, 127.9, 129.4 (2 × C), 130.0 (2 × C). These values are
in good agreement with those reported for this compound.9
Several Michael adducts are known and are identified by
comparison of their spectroscopic data with those reported.
The new compounds are characterized by their
(7) Peach, M. E. The Chemistry of the Thiol Group, Part 2; Patai,
S., Ed.; John Wiley: New York, 1974, 721.
(8) (a) Devan, N.; Sureshkumar, D.; Beadham, I.; Prabhu, K. R.;
Chandrasekaran, S. Indian J. Chem.: Sect. B 2002, 41, 2112.
(b) Ranu, B. C.; Dey, S. S.; Hajra, A. Tetrahedron 2003, 59,
2417; and references cited therein. (c) Srivastava, N.;
Banik, B. K. J. Org. Chem. 2003, 68, 2109. (d) Yadav, J.
S.; Reddy, B. V. S.; Baishya, G. J. Org. Chem. 2003, 68,
7098. (e) Alam, M. M.; Varala, R.; Adapa, S. R.
Tetrahedron Lett. 2003, 44, 5115.
(9) Cherkquaskas, J. P.; Cohen, T. J. Org. Chem. 1992, 57, 6.
spectroscopic data and elemental analysis. These data for a
Synlett 2004, No. 7, 1239–1242 © Thieme Stuttgart · New York