Y. Hou et al. / Tetrahedron Letters 42 (2001) 8607–8610
8609
Ph3C
S
S
R
Ph3C
S
Cl
R
Ph3C
S
S
S
8
3a
+
R
S
S
R
S
Cl
Cl
R
R
9
7
4
R
S
S
S
R
Ph3C Cl
+
1
5
Scheme 3.
Table 2. One sulfur unit insertion into symmetric diamino disulfides
Entry
5
Time (h)
6
Yield (%)
1
2
3
Dimorpholinodisulfide20 (5a)
24
16
24
Dimorpholinotrisulfide21 (2a)
75
85
80
Bis(N-benzyl-N-methyl)disulfide22 (5b)
Bis(N,N-diethyl)disulfide23 (5c)
Bis(N-benzyl-N-methyl)trisulfide22 (2b)
Bis(N,N-diethyl)trisulfide24 (2c)
under these conditions a reaction took place between 6
and the ethanol in commercial chloroform. As a result,
triphenylmethylethyl ether25 was isolated in high yield.
To simplify the reaction products, ethanol-free chloro-
form was used in these cases. In the three entries listed
in Table 2, the trisulfides were formed in good yield; the
tetrasulfide impurity was minor. The three trisulfides
decomposed significantly on a silica gel column (neu-
tral, 230–400 mesh). Alternatively, the mixture was
dissolved in the minimum amount of hexane and the
solution was cooled in a refrigerator (−15°C). Most of
the triphenylmethanol precipitated as a white solid.
Trisulfide 2b was fully purified by a careful recrystal-
lization from a mixture of hexane and ethyl acetate; 2a
and 2c were not fully purified.
2. Banerji, A.; Amonkar, S. V. Bhabba, 1978, Patent IN
75-B0344 19751127.
3. (a) Casnati, G.; Ricca, A.; Pavan, M. Chem. Ind. (Milan)
1967, 49, 57; (b) Miller, A.; Scalan, R. A.; Lee, J. S.;
Libbey, L. M. Appl. Microbiol. 1973, 26, 18; (c)
Yasuhara, A.; Fuwa, K. Bull. Chem. Soc. Jpn. 1977, 50,
3029.
4. (a) Nicolau, K. C.; Hummel, C. W.; Nakada, M.;
Shibayama, K.; Pitsinos, E. N.; Saimoto, H.; Mizuno, Y.;
Baldenius, K.-U.; Smith, A. L. J. Am. Chem. Soc. 1993,
115, 7625; (b) Nicolau, K. C.; Dai, W.-M. Angew. Chem.,
Int. Ed. Engl. 1991, 30, 1387.
5. Kohama, Y.; Lida, K.; Itoh, S.; Tsujikawa, K.; Mimura,
T. Biol. Pharm. Bull. 1996, 19, 876.
6. Katrizky, A. R.; Zhao, X.; Hitchings, G. J. Synlett 1990,
473.
We propose that this reaction shares a parallel mecha-
nism as the reactions between chlorodisulfide 3b12a or
chlorotrisulfide 3c12b with acyclic disulfides. Reagent 3a
shows much less reactivity than the two other reagents;
however, unlike the reaction with 3c, intermediate 8
was never directly observed.
7. (a) Clayton, J. O.; Etzler, D. H. J. Chem. Soc. 1974, 69,
974; (b) Derbesy, G.; Harpp, D. N. Tetrahedron Lett.
1994, 35, 5381.
8. Reid, E. E. Organic Chemistry of Bivalent Sulfur; Chemi-
cal Publishing Company: New York, 1960; Vol. 3, p. 387.
9. Vineyard, B. D. J. Org. Chem. 1966, 31, 601.
10. (a) Buckman, J. D.; Field, L. J. Org. Chem. 1967, 454; (b)
See: Steudel, R.; Kustos, M. In Encyclopedia of Inorganic
Chemistry; King, B., Ed.; J. Wiley: Sussex, 1994; Vol. 7,
pp. 4009–4038.
11. Capozzi, G.; Cappericci, A.; Degl’Innicenti, A.; Duce, D.
R.; Menichetti, S. Tetrahedron Lett. 1989, 30, 2991.
12. (a) Rys, A. Z.; Harpp, D. N. Tetrahedron Lett. 2000, 41,
7169; (b) Hou, Y.; Abu-Yousef, A. I.; Harpp, D. N.
Tetrahedron Lett. 2000, 41, 7809.
In conclusion, the current method provides a novel and
convenient preparation of some acyclic symmetric
trisulfides from easily accessible starting materials
under very mild conditions.
Acknowledgements
13. (a) Sigma-Aldrich Inc; (b) Vorlander, D.; Mittag, E.
We thank the National Science and Engineering
Research Council of Canada for financial support.
Chem. Ber. 1913, 46, 3450.
14. (a) Abu-Yousef, I. A.; Harpp, D. N. J. Org. Chem. 1997,
62, 8366; (b) Abu-Yousef, I. A.; Harpp, D. N. J. Org.
Chem. 1998, 63, 8654.
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