P. Del Buttero et al. / Tetrahedron: Asymmetry 14 (2003) 3949–3953
3953
and filtered over a pad of Celite. The organic layer was
evaporated under reduced pressure and the residue was
crystallised by ethanol giving 4a,b or 9.
Compound (3S,4R)-5b: [h]D=−144.2 (CHCl3, c 0.57)
[from (3S,4R)-4b].
Compounds 10: (0.09 g, 45%); undistillable yellow oil;
IR: (Nujol) 3385, 3315, 1750 (cm−1); 1H NMR l 1.70 (s,
2H), 3.75 (s, 3H), 3.82 (s, 3H), 4.50 (dd, J 4.7, 5.5 Hz,
1H), 4.80 (dd, J 7.6, 5.5 Hz, 1H), 6.26 (dd, J 7.6, 16.1
Hz, 1H), 7.11 (d, J 16.1 Hz, 1H), 6.8–7.5 (m, 8H); MS:
m/z 324 (M+). Anal. calcd for C19H20N2O3 C, 70.35; H,
6.21; N, 8.64. Found: C, 70.40; H, 6.20; N, 8.65.
Compound 4a: (0.16 g, 95%); mp 208°C (from ethanol);
IR: (Nujol) 1800, 1760, 1720 (cm−1); 1H NMR l 3.60 (s,
3H), 3.80 (s, 3H), 5.60 (d, J 5.44 Hz, 1H), 5.80 (d, J
5.44 Hz, 1H), 6.6–7.6 (m, 12H); MS: m/z 428 (M+).
Anal. calcd for C25H20N2O5 C, 70.08; H, 4.71; N, 6.54.
Found: C, 70.10; H, 4.70; N, 6.55.
Compound (3S,4R)-4a: [h]D=−31.0 (CHCl3 c 0.025).
Compound (3S,4R)-10: [h]D=+162 (CHCl3, c 0.2
CHCl3).
Compound 4b: (0.17 g, 97%); mp 198°C (from ethanol);
IR: (Nujol) 1785, 1758, 1727 (cm−1); 1H NMR l 3.80 (s,
3H); 5.70 (d, J 5.5 Hz, 1H); 5.80 (d, J 5.5 Hz, 1H); 6.90
(AB system, 2H); 7.70 (m, 4H); MS: m/z 416 (M+).
Anal. calcd for C24H17N2O4F C, 69.23; H, 4.12; N,
6.73. Found: C, 69.20; H, 4.11; N, 6.70.
Acknowledgements
Thanks are due to MURST and CNR for financial
support.
Compound (3S,4R)-4b: [h]D=−4.8 (CHCl3, c 0.25).
Compounds 9: (0.18 g, 86%); IR: (Nujol) 1785, 1750,
1
1710 (cm−1); H NMR l 3.78 (s, 1H), 3.80 (s, 3H), 5.10
References
(dd, J 5.5, 16.19 Hz, 1H), 5.68 (d, J 5.5 Hz, 1H), 5.68
(dd, J=8.9, 16.2 Hz, 1H); 7.10 (d, J 16.2 Hz, 1H);
6.8–7.7 (m, 12H); MS: m/z 454 (M+). Anal. calcd for
C27H22N2O5 C, 71.35; H, 4.88; N, 6.16. Found: C,
71.33; H, 4.85; N, 6.74. e.e. ]98% by 1H NMR
(Eu(hfc)3. [h]D25=+578.6 (CHCl3, c 0.02 CHCl3)
1. Samarendra, C. I.; Maiti, N.; Micetich, R.; Daneshtalab,
M.; Atchison, K.; Phillips, O. A.; Kunugita, C. J.
Antibiot. 1994, 47, 1030.
2. (a) Chemistry and Biology of i-Lactam Antibiotics Mor-
ris, R. B.; Gorman, M., Eds.; Academic Press: New
York, 1982; (b) Niccolai, D.; Tarsi, L.; Thomas, R. J.
Chem. Commun. 1997, 2333.
3. Sammes, P. G. Chem. Rev. 1976, 76, 113.
4. The Organic Chemistry of i-Lactams; Georg, G. I., Ed.;
VCH Press: New York, 1993.
5. Davies, S. G.; McCarthy, T. D. In Comprehensive
Organometallic Chemistry II; Abel, E. W.; Stone, F. G.;
Wilkinson, G., Eds.; Pergamon Press: Oxford, 1995; Vol.
12.
4.3. Cleavage of the phthalimido group. General
procedure
To a suspension of 4a,b or 9 (0.6 mmol) and hydrazine
dihydrochloride (0.83 g, 2.7 mmol) in dry methanol (8.0
mL), a solution of triethylamine (0.7 mL, 5.4 mmol) in
dry methanol (1.0 mL) was added dropwise. The mix-
ture was heated at 40°C for 4 h and then cooled, added
with water (30 mL) and extracted with ethyl acetate.
The solvent was evaporated and the residue was chro-
6. Sheenan, J. C.; Ryan, J. J. J. Am. Chem. Soc. 1951, 73,
1204.
matographed on
a
silica gel column with
7. (a) Prasad, J. S.; Liebeskind, L. S. Tetrahedron Lett.
1988, 29, 4253; (b) Palomo, C.; Arrieta, A.; Cossio, F. P.;
Aizpurna, J. M.; Mielgo, A.; Aurrekoetxea, N. Tetra-
hedron Lett. 1990, 31, 6429.
8. (a) Osby, J. O.; Martin, M. G.; Ganem, B. Tetrahedron
Lett. 1984, 25, 2093; (b) Kambya, T.; Hashimoto, M.;
Nakaguchi, O.; Oku, T. Tetrahedron 1978, 35, 323.
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10. Hegedus, L. S.; Montgomery, J.; Narukawa, Y.; Snustad,
D. C. J. Am. Chem. Soc. 1991, 113, 5784.
dichloromethane: ethyl acetate 1:1 giving 5a,b or 10.
Compound 5a: (0.12 g, 67%); mp 209°C (from
dichloromethane/ethyl acetate 1:1); IR: (Nujol) 3400,
1
3350, 1740 (cm−1); H NMR l 1.60 (br s, 2H), 3.70 (s,
3H), 3.85 (s, 3H), 4.60 (d, J 5.4 Hz, 1H), 5.50 (d, J=5.4
Hz, 1H), 6.8-7.1 (m, 8H); MS: m/z 298 (M+). Anal.
calcd for C17H18N2O3 C, 68.44; H, 6.08; N, 9.39.
Found: C, 68.34; H, 6.07; N, 9.36.
11. Solladie`-Cavallo, A. In Advances in Metal-Organic
Chemistry; Liebeskind, L. S., Ed.; JAI Press: Greenwich,
1989; Vol. 1, p. 99.
Compound (3S,4R)-5a: [h]D=−80.0 (CHCl3, c 0.10)
[from (3S,4R)-4a].
12. Baldoli, C.; Del Buttero, P.; Licandro, E.; Maiorana, S.;
Papagni, A. Tetrahedron: Asymmetry 1994, 5, 809.
13. Stewart, J. J. P. J. Comput. Chem. 1989, 10, 209 and 221.
14. As implemented in the Hyper Chem Release 6.01 version
for Windows; Hypercube Inc., 2000.
15. Coss´ıo, F. P.; Arrieta, A.; Lecea, B.; Ulgade, J. M. J. Am.
Chem. Soc. 1994, 116, 2085.
Compound 5b: (0.14 g, 81%); mp 120°C (from
dichloromethane/ethyl acetate 1:1); IR: (Nujol) 3390,
1
3310, 1745 (cm−1); H NMR l 1.60 (br s, 2H), 3.80 (s,
3H), 4.70 (d, J 5.4 Hz, 1H), 5.50 (d, J 5.4 Hz, 1H),
6.8–7.3 (m, 8H); MS: m/z 286 (M+). Anal. calcd for
C16H15N2O2F C, 67.12; H, 5.28; N, 9.78. Found: C,
67.20; H, 5.26; N, 9.76.