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B. Jiang et al. / Tetrahedron: Asymmetry 12 (2001) 2323–2329
room temperature and stirred for 5 h, followed by
addition of CH2Cl2 (30 mL). The organic phase was
washed with brine and then dried and concentrated.
The amide was obtained as a white solid which was
used without further purification.
37, 1986 (review of enantioselective borane reduction of
carbonyl compounds).
2. Noyori, R.; Kitamura, M. Angew. Chem., Int. Ed. 1991,
30, 49 (review of enantioselective addition of organo-
metallic reagents to carbonyl compounds).
3. Steinhaqgen, H.; Helmenhen, G. Angew. Chem., Int.
Ed. 1996, 35, 2339 (review of asymmetric catalysis with
bimetallic compounds).
4. Itsuno, S.; Hirao, A.; Nakahama, S.; Yamazaki, N. J.
Chem. Soc., Perkin Trans. 1 1983, 1673.
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To the solution of the amide in freshly-distilled toluene
(10 mL) was added a solution of borane–dimethyl
sulfide (10 M, 1 mL, 10 mmol) in THF. The mixture
was refluxed for 6 h under argon. Then aqueous HCl
(2N, 10 mL) was added and the resulting mixture was
stirred for 24 h. After neutralization with 2N NaOH,
the reaction mixture was extracted with ether. The
combined ethereal extract was washed with brine, dried
and then concentrated. The residue was purified by
silica gel column (CH2Cl2/MeOH, 9/1) to give com-
pound 7a as a pale yellow oil (717 mg, 87%). [h]D20
=−89.3 (c, 2.5, CHCl3); IR: 3061, 2955, 2926, 2856,
1732, 1601, 1454, 1126 cm−1; 1H NMR (300 Hz,
CDCl3) l: 7.28–7.16 (m 10H), 3.38 (s, 2H), 2.99–2.47
(m, 10H), 1.54–1.22 (m, 8H), 0.92 (t, 6H, J=7.2 Hz);
MS (EI) m/z: 413, 248, 236, 230, 206, 176, 120, 91;
HRMS (EI): calcd for C26H40N2O2: 412.3125, found:
412.3160.
4.7. (2R,3S,4S,5R)-N,N%-Dibenzyl-2,5-diamino-3,4-dihy-
droxy-1,6-diphenylhexane 7b
Compound 7b was prepared by the same procedure
as 7a using benzoyl chloride instead of n-butylryl
chloride in 87% yield as a foam. [h]2D0=−75.3 (c, 3.1,
CHCl3); IR: 3063, 2921, 2854, 1603 cm−1; 1H NMR
(300 Hz, CDCl3) l: 7.36–7.13 (m 10H), 3.97 (d, 2H,
J 12.5 Hz), 3.74 (d, 2H, J 12.5 Hz), 3.34 (s, 2H), 3.06
(dd, 2H, J 3.4 Hz, 12.1 Hz), 2.87–2.74 (m, 4H); MS
(EI) m/z: 481, 282, 270, 264, 240, 210. HRMS (EI):
calcd for C30H36N2O2: 480.2754, found: 480.2731.
15. Corey, E. J.; Imwinkelried, R.; Pikul, S.; Xiang, Y. B.
J. Am. Chem. Soc. 1989, 111, 5943.
16. Schreiner, E. P.; Pruckner, A. J. Org. Chem. 1997, 62,
5380.
17. Pierce, M. E.; Harris, G. D.; Islam, Q.; Radesca, L. A.;
Storace, L.; Waltermire, R. E.; Wat, E.; Jadhav, P. K.;
Emmett, G. C. J. Org. Chem. 1996, 61, 444.
18. Rossano, L. T.; Lo, Y. S.; Anzalone, L.; Lee, Y.-C.;
Meloni, D. J.; Moore, J. R.; Gale, T. M.; Arnett, J. F.
Tetrahedron Lett. 1995, 36, 4967.
4.8. General procedure of asymmetric addition of
diethylzinc to aldehyde
To a solution of the ligand (0.1 mmol) in freshly
distilled toluene (1.5 mL) was added aldehyde (1
mmol), followed by addition of diethylzinc (1.1 M in
toluene, 1 mL, 1.1 mmol). The mixture was then
19. Itsuno, S.; Ito, K.; Hirao, A.; Nakahama, S. J. Chem.
Soc., Chem. Commun. 1983, 469.
20. Itsuno, S.; Sakurai, Y.; Ito, K.; Nakahama, S. Bull.
Chem. Soc. Jpn. 1987, 60, 95.
21. Corey, E. J.; Bakshi, R. K.; Shibata, S.; Chen, C.;
Sigh, V. K. J. Am. Chem. Soc. 1987, 109, 7925.
22. Corey, E. J.; Bakshi, R. K.; Shibata, S. J. Am. Chem.
Soc. 1987, 109, 5551.
23. Corey, E. J.; Shibata, S.; Bakshi, R. K. J. Org. Chem.
1988, 53, 2861.
maintained at room temperature for 48
h and
quenched with aqueous NH4Cl (2N, 1 mL). Ether
was added to dilute the mixture. The organic layer
was washed with brine and then dried. After the sol-
vent was removed the product was purified on a silica
gel column.
24. Hirao, A.; Itsuno, S.; Nakahama, S.; Yamazaki, N. J.
Chem. Soc., Chem. Commun. 1981, 315.
25. Zhao, J.; Bao, X.; Liu, X.; Wan, B.; Han, X.; Yang,
C.; Hang, J.; Feng, Y.; Jiang, B. Tetrahedron: Asymme-
try 2000, 11, 3351.
Acknowledgements
This work was supported by the National Natural
Sciences Foundation of China.
26. Zhao, J.; Liu, X.; Han, X.; Wan, B.; Bao, X.; Hang, J.;
Jiang, B. Intl. Lab. 2000, 30, 10.
27. Zhao, J.; Han, X.; Liu, X.; Bao, X.; Hang, J.; Jiang, B.
Sci. China Ser. B 2000, 43, 40.
28. Dai, W. M.; Zhu, H. J.; Hao, X. J. Tetrahedron: Asym-
metry 2000, 11, 2315 and references cited therein.
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