5340
A. Akao et al. / Tetrahedron Letters 47 (2006) 5337–5340
Synthesis 1983, 751; (c) Testaferri, L.; Tiecco, M.; Tingoli,
M.; Bartoli, D.; Massoli, A. Tetrahedron 1985, 41, 1373.
6. The yield of deprotected products (PhSH and (PhS)
2
) was
95% (68%+27%). (PhS) can be readily converted into
2
2
. (a) Pinchart, A.; Dallaire, C.; Van Bierbeek, A.; Gingras,
M. Tetrahedron Lett. 1999, 40, 5479; (b) Cabiddu, S.;
Melis, S.; Piras, P. P.; Sotgiu, F. Synthesis 1982, 583.
. (a) Wolman, Y. In The Chemistry of the Thiol Group;
Patai, S., Ed.; John Wiley & Sons: New York, 1974; p 669;
PhSH by NaBH reduction: Ookawa, A.; Yokoyama, S.;
Soai, K. Synth. Commun. 1986, 16, 819.
7. General procedure for de-benzylation reaction: To a
4
3
mixture of
(5.8 mg, 0.0231 mmol), diglyme (0.5 mL) was added under
. After cooling in an ice-water bath, the mixture was
2 2
1 (46.3 mg, 0.231 mmol) and Cp TiCl
(
b) Hiskey, R. G.; Rao, V. R.; Rhodes, W. G. In
N
2
Protective Groups in Organic Chemistry; McOmie, J. F.
W., Ed.; Plenum Press: New York, 1973; (c) McOmie, J.
F. W. Adv. Org. Chem. 1963, 3, 251.
treated with dibutylmagnesium, 1.0 M solution in heptane
(0.58 mL, 0.58 mmol), stirred for 1 h and quenched with
1 N aqueous NaOH (2 mL). The resulting mixture was
4
. Greene, T. W.; Wuts, P. G. M. Protective Groups in
Organic Synthesis, 3rd ed.; John Wiley & Sons: New York,
3 2
diluted to 100 mL with CH CN–H O and analyzed by
HPLC, which showed 2 (24.6 assay mg, 97% yield) and 3
(0.7 assay mg, 3% yield), respectively.
1999, Chapter 6.
5
. (a) Iida, T.; Wada, T.; Tomimoto, K.; Mase, T. Tetra-
hedron Lett. 2001, 42, 4841; (b) Kii, S.; Akao, A.;
Nonoyama, N.; Mase, T.; Yasuda, N. Tetrahedron Lett.
8. (a) Terao, J.; Saito, K.; Nii, S.; Kambe, N.; Sonoda, N.
J. Am. Chem. Soc. 1998, 120, 11822; (b) Nii, S.; Terao, J.;
Kambe, N. J. Org. Chem. 2000, 65, 5291.
2
006, 47, 1877; (c) Kitagawa, K.; Inoue, A.; Shinokubo,
9. (a) Gans a¨ uer, A. Synlett 1998, 801; (b) RajanBabu, T. V.;
Nugent, W. A. J. Am. Chem. Soc. 1994, 116, 986.
10. Inoue, A.; Shinokubo, H.; Oshima, K. Org. Lett. 2000, 2,
651.
11. (a) Wakabayashi, K.; Yorimitsu, H.; Oshima, K. J. Am.
Chem. Soc. 2001, 123, 5374; (b) Hayashi, Y.; Shinokubo,
H.; Oshima, K. Tetrahedron Lett. 1998, 39, 63.
H.; Oshima, K. Angew. Chem., Int. Ed. 2000, 39, 2481; (d)
Inoue, A.; Kitagawa, K.; Shinokubo, H.; Oshima, K. J.
Org. Chem. 2001, 66, 4333; (e) Dumouchel, S.; Mongin,
F.; Tr e´ court, F.; Qu e´ guiner, G. Tetrahedron Lett. 2003,
4
4, 2033; (f) Dumouchel, S.; Mongin, F.; Tr e´ court, F.;
Qu e´ guiner, G. Tetrahedron 2003, 59, 8629.