2790
K. Ohata, S. Terashima / Tetrahedron Letters 47 (2006) 2787–2791
MeCOSH
Et3N
by employing this synthetic scheme. Research along this
line is in progress.
OMe
OMe
1) NaOMe/MeOH
OMe
OMe
Br
AcS
2) I
2 87%
~100%
i
OMe
Acknowledgements
RSO2Na/I2
MeO
S
RSO2S
OMe
a : 86%
b : 95%
6
We are grateful to Dr. T. Ishizaki of Kyorin Pharmaceu-
tical Co. Ltd. for extensive support and Dr. Y. Fukuda
of Kyorin Pharmaceutical Co. Ltd. for valuable sugges-
tions and discussions.
OMe
2
a : R = Me
b : R = -C6H4p-Me
14. Petroski, R. J.; Weisleder, D. Synth. Commun. 2001, 31,
89–95.
15. Ho, G. J.; Mathre, D. J. J. Org. Chem. 1995, 60, 2271–2273.
16. Prior to selecting 6 as a sulfenylating agent, various S-
electrophiles were examined in the preliminary experiments.
Thus, acetylsulfenyl chloride which was initially considered
to be one of the most attractive S-electrophiles turned out
not to react with 7 at all. While methyl methanethiosulfo-
nate (MeSSO2Me) and (2-trimethylsilyl)ethyl p-toluene-
thiosulfonate (TMSCH2CH2SSO2C6H4p-Me) underwent
deconjugative asymmetric a-sulfenylation similar to 1, the
methylsulfenyl and the (2-trimethylsilyl)ethylsulfenyl group
introduced into the reaction products could not be elabo-
rated to a thiol or an acylsulfenyl group.
References and notes
1. Oishi, H.; Noto, T.; Sasaki, H.; Suzuki, K.; Hayashi, T.;
Okazaki, H.; Ando, K.; Sawada, M. J. Antibiot. 1982, 35,
391–395.
2. (a) Noto, T.; Miyakawa, S.; Oishi, H.; Endo, H.; Okazaki,
H. J. Antibiot. 1982, 35, 401–410; (b) Miyakawa, S.;
Suzuki, K.; Noto, T.; Harada, Y.; Okazaki, H. J. Antibiot.
1982, 35, 411–419.
3. (a) Kremer, L.; Douglas, J. D.; Baulard, A. R.; More-
house, C.; Guy, M. R.; Alland, D.; Dover, L. G.; Lakey, J.
H.; Jacobs, W. R.; Brennan, P. J.; Minnikin, D. E.; Besra,
G. S. J. Biol. Chem. 2000, 275, 16857–16864; (b) Slayden,
R. A.; Lee, R. E.; Armour, J. W.; Cooper, A. M.; Orme, I.
M.; Brennan, P. J.; Besra, G. S. Antimicrob. Agents
Chemother. 1996, 40, 2813–2819.
4. (a) Waller, R. F.; Ralph, S. A.; Reed, M. B.; Su, V.;
Douglas, J. D.; Minnikin, D. E.; Cowman, A. F.; Besra,
G. S.; McFadden, G. I. Antimicrob. Agents Chemother.
2003, 47, 297–301; (b) Jones, S. M.; Urch, J. E.; Brun, R.;
Harwood, J. L.; Berry, C.; Gilbert, I. H. Bioorg. Med.
Chem. 2004, 12, 683–692.
5. (a) Jackowski, S.; Murphy, C. M.; Cronan, J. E.; Rock, C.
O. J. Biol. Chem. 1989, 264, 7624–7629; (b) Price, A. C.;
Choi, K.-H.; Heath, R. J.; Li, Z.; White, S. W.; Rock, C.
O. J. Biol. Chem. 2001, 276, 6551–6559.
6. (a) Hayashi, T.; Yamamoto, O.; Sasaki, H.; Kawaguchi,
A.; Okazaki, H. Biochem. Biophys. Res. Commun. 1983,
115, 1108–1113; (b) Nishida, I.; Kawaguchi, A.; Yamada,
M. J. Biochem. (Tokyo) 1986, 99, 1447–1454.
7. McFadden, J. M.; Medghalchi, S. M.; Thupari, J. N.;
Pinn, M. L.; Vadlamudi, A.; Miller, K. I.; Kuhajda,
F. P.; Townsend, C. A. J. Med. Chem. 2005, 48, 946–
961.
8. Wang, C. L.; Salvino, J. M. Tetrahedron Lett. 1984, 25,
5243–5246.
17. Separation of 5, the (30Z)-isomer of 5 and 11 was
performed by HPLC with a chiral column [Daicel Chir-
alpak
AD-H,
B2.0 cm · 25 cm,
hexane/EtOH/
iPrOH = 91:6:3, flow rate 10 mL/min]. HPLC analysis
[Daicel Chiralpak AD-H, B0.46 cm · 25 cm, hexane/
iPrOH = 95:5, flow rate 1.0 mL/min; tR 14.7 min (5),
10.4 min [the (30Z)-isomer of 5], 25.1 min (11)].
18. Representative physical and spectral data of 5, the (30Z)-
isomer of 5, and 11 are as follows. Compound 5, oil,
23
½aꢁD ꢀ253 (c 0.50, MeOH), 1H NMR (CDCl3) d (ppm):
1.72 (3H, d, J = 1.2 Hz), 1.82–1.89 (2H, m), 1.95 (3H, s),
2.62 (2H, t, J = 7.3 Hz), 2.72 (1H, dd, J = 13, 10 Hz),
3.318 (3H, s), 3.324 (3H, s), 3.27–3.38 (1H, m), 4.09–4.14
(2H, m), 4.48 (1H, t, J = 5.5 Hz), 4.65–4.71 (1H, m), 5.01
(1H, d, J = 11 Hz), 5.14 (1H, d, J = 17 Hz), 5.72 (1H, s),
6.36 (1H, dd, J = 17, 11 Hz), 7.22–7.36 (5H, m). MS (EI+)
(m/z): 433 (M+), HRMS (EI+) (m/z): Calcd for
C23H31NO5S (M+): 433.1923. Found 433.1941.
(30Z)-Isomer of 5, oil, 1H NMR (CDCl3) d (ppm): 1.83
(3H, d, J = 1.2 Hz), 1.83–1.90 (2H, m), 1.96 (3H, s), 2.65–
2.74 (3H, m), 3.318 (3H, s), 3.324 (3H, s), 3.29–3.37 (1H,
m), 4.04 (1H, q, J = 7.9 Hz), 4.09 (1H, dd, J = 8.6,
2.4 Hz), 4.48 (1H, t, J = 6.1 Hz), 4.59–4.63 (1H, m), 5.11
(1H, d, J = 11 Hz), 5.22 (1H, d, J = 17 Hz), 5.60 (1H, s),
6.62 (1H, dd, J = 17, 11 Hz), 7.22–7.36 (5H, m). MS (EI+)
(m/z): 433 (M+), HRMS (EI+) (m/z): Calcd for
C23H31NO5S (M+): 433.1923. Found 433.1901.
9. (a) Chambers, M. S.; Thomas, E. J.; Williams, D. J. J.
Chem. Soc., Chem. Commun. 1987, 1228–1230; (b) Cham-
bers, M. S.; Thomas, E. J. J. Chem. Soc., Chem. Commun.
1989, 23–24; (c) Chambers, M. S.; Thomas, E. J. J. Chem.
Soc., Perkin Trans. 1 1997, 417–431.
Compound 11, oil, 1H NMR (CDCl3) d (ppm): 1.71 (3H, d,
J = 1.2 Hz), 1.84 (3H, s), 1.84–1.91 (2H, m), 2.59–2.70 (3H,
m), 3.313 (3H, s), 3.318 (3H, s), 3.34(1H, dd, J = 13, 3.1 Hz),
4.06–4.14 (2H, m), 4.47 (1H, t, J = 5.5 Hz), 4.65–4.70 (1H,
m), 5.01 (1H, d, J = 11 Hz), 5.13 (1H, d, J = 18 Hz), 5.77
(1H, s), 6.36 (1H, dd, J = 18, 11 Hz), 7.24–7.37 (5H, m). MS
(CI+) (m/z): 434 (M+H), HRMS (CI+) (m/z): Calcd for
C23H32NO5S (M+H): 434.2001. Found 434.1967.
10. McFadden, J. M.; Frehywot, G. L.; Townsend, C. A. Org.
Lett. 2002, 4, 3859–3862.
11. Deconjugative asymmetric allylation of a dienolate with
formation of a quarternary asymmetric center has been
recently reported by Kobayashi et al. Abe, T.; Suzuki, T.;
Sekiguchi, K.; Hosokawa, S.; Kobayashi, S. Tetrahedron
Lett. 2003, 44, 9303–9305.
12. Evans, D. A.; Britton, T. C.; Ellman, J. A.; Dorow, R. L.
J. Am. Chem. Soc. 1990, 112, 4011–4030.
13. According to the procedure reported by Fujiki et al., 6 was
prepared from 3-bromopropionaldehyde dimethylacetal
(i) as shown below. Fujiki, K.; Tanifuji, N.; Sakaki, Y.;
Yokoyama, T. Synthesis 2002, 343–348.
19. The structure of the (30Z)-isomer of 5 was determined by
NOESY spectrum which was observed between C-30 H
and C-40 Me.
20. Taking into account its electronic and steric effects, it is
anticipated that I can participate in the reaction more
preferentially than II. See: Hosokawa, S.; Sekiguchi, K.;
Enemoto, M.; Kobayashi, S. Tetrahedron Lett. 2000, 41,
6429–6433.