4260
C. Neri, J. M. J. Williams / Tetrahedron Letters 43 (2002) 4257–4260
calcd for C17H21NO5: C, 63.93; H, 6.62; N, 4.38. Found:
References
1. Hinterman, T.; Seebach, D. Helv. Chim. Acta 1998, 81,
C, 63.54; H, 6.59; N, 4.22%.
9. (a) Rabillier, C. G.; Ko¨nisberger, K.; Faber, K.; Grien-
gel, H. Tetrahedron 1990, 12, 4231; (b) Wejtje, E.; Adler-
creuz, P. Biotech. Bioeng. 1997, 55, 789; (c) Tawaki, S.;
Klibanov, A. M. J. Am. Chem. Soc. 1992, 114, 1882.
10. For an example, see: Kijima, T.; Moriya, T.; Kondoh, E.;
Izumi, T. Tetrahedron Lett. 2000, 41, 2125.
2093.
2. Haughton, L.; Williams, J. M. J.; Zimmerman, J. A.
Tetrahedron: Asymmetry 2000, 11, 1697.
3. (a) Evans, D. A.; Bartroli, H.; Shih, T. L. J. Am. Chem.
Soc. 1981, 103, 2127; (b) Evans, D. A.; Sjorgren, E. B.
Tetrahedron Lett. 1985, 26, 3788; (c) Evans, D. A.;
Weber, A. E. J. Am. Chem. Soc. 1986, 108, 6757.
4. (a) Wu, Y.; Shen, X. Tetrahedron: Asymmetry 2000, 11,
4353; (b) Gage, J. R.; Evans, D. A. Org. Synth. 1990, 83.
5. Crimmins, M. T.; King, B. W.; Taber, E. A.; Chaudary,
K. J. Org. Chem. 2001, 66, 896.
6. The syn relative configuration for aldol adducts 3 was
established from the observed 1H NMR coupling con-
stants for the vicinal protons at the newly created stereo-
genic centres and by comparison of the specific rotations
of the free hydroxy acids after cleavage of the auxiliary.
(−)-Sparteine was used as a convenient base and did not,
as expected (see Ref. 5), exert any stereocontrol.
7. Enzyme Catalysis in Organic Synthesis; Drauz, K.; Wald-
man, H., Eds.; VCH: Weinheim, 1995; Vol. I, pp. 201–
271.
8. (4S,2%S,3%R)-N-(3-Acetoxy-2-methylbutanoyl)-4-benzyl-2-
oxazolidinone 4: yellow needles; mp 79–80°C; [h]3D0=+77.7
(0.99, CHCl3); 1H NMR (300 MHz, CDCl3): lH=1.22
(d, J=6.9 Hz, 3H), 1.28 (d, J=6.5 Hz, 3H), 2.05 (s, 3H),
2.76 (dd, J=9.7 and 13.3 Hz, 1H), 3.27 (dd, J=3.1 and
13.2 Hz, 1H), 3.95 (dq, J=4.3 and 6.9 Hz, 1H), 4.08–4.28
(m, 2H), 4.56–4.64 (m, 1H), 5.30 (dq, J1=4.3 and 6.4 Hz,
1H), 7.19–7.36 (m, 5H); 13C NMR (75.5 MHz, CDCl3):
lC=8.9, 16.2, 19.3 36.1, 40.5, 54.0, 64.5, 68.4, 125.5,
127.1 (2C), 127.6 (2C), 133.5, 151.7, 168.8, 172.2; IR
11. Spectroscopic data were in agreement with those reported
by Harris, R. C.; Cutter, A. L.; Weissman, K. J.; Hane-
feld, U.; Timoney, M. C.; Staunton, J. J. Chem. Res. (M)
1998, 1228. (2R,3S)-5: [h]3D0=+6.9 (c 1.02, CHCl3);
(2S,3R)-5: [h]3D0=−6.8 (1.02, CHCl3). (R)-1a and (S)-1b
presented the same spectroscopic data and specific rota-
tions of the commercial enantiomers.
12. Smith, G. A.; Gowley, R. E. Org. Synth. 1985, 63, 136.
13. Kimura, K.; Murata, K.; Otsuka, K.; Ishizuka, T.;
Harakate, M.; Kuneida, T. Tetrahedron Lett. 1992, 33,
4461.
14. Commercial product from Aldrich.
15. (4S,2%S,3%R)-N-(3-Acetoxy-2-methylbutanoyl)-4-ethyl-2-
oxazolidinone 7: yellow oil; [h]3D0=−86.6 (c 0.35, CHCl3);
1H NMR (300 MHz, CDCl3): lH 0.92 (t, J=7.5 Hz, 3H),
1.19 (d, J=6.9 Hz, 3H), 1.26 (d, J=6.4 Hz, 3H), 1.72–
1.82 (m, 2H), 2.02 (s, 3H), 3.96 (dq, J=3.4 and 6.9 Hz,
1H), 4.13 (dd, J=1.8 and 8.0 Hz, 1H), 4.35–4.44 (m, 2H),
5.27 (dq, J=3.2 and 6.4 Hz, 1H); 13C NMR (75.5 MHz,
CDCl3) lC=8.2, 11.0, 18.1, 21.1, 25.1, 42.1, 55.6, 66.8,
70.3, 153.8, 170.6, 174.0; IR (neat): wmax 1780, 1735, 1700,
1385, 1370, 1240, 1210 cm−1; MS (70 eV): m/z (%): 258
+
Da (M +1, 55%), 198 (100), 143 (21), 83 (40). Anal.
calcd for C12H19NO5: C, 56.02; H, 7.44; N, 5.44. Found:
C, 55.60; H, 7.47; N, 5.38%.
16. Spectroscopic data were in agreement with those reported
by Iwama, S.; Katsamura, S. Bull. Chem. Soc. Jpn. 1994,
67, 3363; (R)-8: [h]D30=+5.7 (0.30, CHCl3); (S)-8b: [h]D30=
−5.5 (0.30, CHCl3).
(CH2Cl2): wmax 2975, 1780, 1735, 1695, 1450, 1370, 1225,
+
1110 cm−1. MS (70 eV): m/z (%): 319 Da (M , 10%), 259
(57), 244 (46), 178 (30), 83 (95), 43 (100). Acc. mass EI+:
319.1420 Da, calcd for C17H21NO5 319.1417 Da. Anal.