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8
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benzaldehyde (680 mg, 5 mmol) and 1,3-propanedithiol
(648 mg, 6 mmol) in acetonitrile (25 mL) was added
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2. Anand, R. V.; Sarvanan, P.; Singh, V. K. Synlett 1999,
1
1
1
Y(OTf)
3
(135 mg, 5 mol %) at room temperature. The
4
3. Kamitori, Y.; Hojo, M.; Masuda, R.; Kimura, T.;
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13.
reaction mixture was stirred at room temperature for
25 min, diluted with ethyl acetate (100 mL), washed with
water (50 mL), dried (MgSO ), and concentrated in vacuo.
4
1
1
1
1
1
The crude product was purified by silica gel column
chromatography (15% ethyl acetate in hexane) to afford
4
621.
1
5. Khan, A. T.; Mondal, E.; Sahu, P. R.; Islam, S. Tetra-
hedron Lett. 2003, 44, 919.
6. Srivastava, N.; Dashgupta, S. K.; Banik, B. K. Tetra-
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7. Leonard, N. M.; Oswald, M. C.; Friederg, D. A.; Nattier,
B. A.; Smith, R. C.; Mohan, R. S. J. Org. Chem. 2002, 67,
pure 2-(4-methoxy)phenyl-1,3-dithiane (93%). H NMR
3
(500 MHz, CDCl ) d 1.86–1.98 (m, 1H), 2.10–2.18 (m,
1H), 2.85–2.95 (m, 2H), 2.98–3.10 (m, 2H), 3.79 (s, 3H),
5.13 (s, 1H), 6.86 (d, J ¼ 8:5 Hz, 2H), 7.39 (d, J ¼ 8:5 Hz,
2H). The aqueous layer containing the catalyst could be
evaporated under reduced pressure to give a white solid.
The IR spectrumof the recovered catalyst was identical to
that of the commercially available catalyst (Aldrich),
which could be reused for the next thioacetalyzation
reaction, without losing any significant activity (Table 1,
entries 2 and 21).
5
202.
8. Firouzabadi, H.; Iranpoor, N.; Karimi, B. Synthesis 1999,
8.
9. Yadav, J. S.; Reddy, B. S.; Pandey, S. K. Synlett 2001,
38.
1
1
5
2