1658
S. Sengupta et al. / Tetrahedron: Asymmetry 10 (1999) 1653–1659
Hz), 3.71 (ddd, 1H, J=2.6, 4.8, 8 Hz), 4.15 (ddd, 1H, J=8, 8, 8 Hz), 7.19 (m, 5H), 7.69 (m, 2H), 7.79 (m,
2H); found: C, 73.42; H, 5.23; N, 4.70; C18H15NO3 requires: C, 73.72; H, 5.11; N, 4.77%.
3.3.3. (R)-[10(S)-Phthalimidoethyl]oxirane 1c
Mp 95–96°C (pet. ether–EtOAc); [α]D +16.16 (c 1.2); IR (KBr): 1770, 1710 cm−1; 1H NMR: 1.50 (d,
3H, J=7.2 Hz), 2.73 (dd, 1H, J=2.4, 4.8 Hz), 2.9 (dd, 1H, J=4.5, 4.5 Hz), 3.60 (ddd, 1H, J=2.4, 3.8, 7.7
Hz), 4.06 (qnt, 1H, J=7.2 Hz), 7.71 (m, 2H), 7.83 (m, 2H); found: C, 66.00; H, 5.23; N, 6.38; C12H11NO3
requires: C, 66.35; H, 5.06; N, 6.45%.
3.4. (R)-[(20-Benzyloxy-10(S)-phthalimido)ethyl]oxirane 1d
LiAlH(OBu-t)3 (0.12 g, 0.47 mmol) was added to a solution of the bromoketone 4d (0.09 g, 0.22
mmol) in THF (5 ml) at −78°C. After 1 h at this temperature, another portion of LiAlH(OBu-t)3 (0.06 g,
0.24 mmol) was added to the reaction mixture. After stirring for a further 1 h, water was added at −78°C
and the mixture extracted with ether (3×10 ml). The ether layer was dried, concentrated under reduced
pressure and the residue chromatographed on silica gel (20% EtOAc in pet. ether) to give the α-amino
epoxide 1d (0.025 g, 35%).
1
Oil; [α]D −0.5 (c 1.2); IR (CHCl3): 1780, 1710 cm−1; H NMR: 2.74 (m, 1H), 2.90 (m, 1H), 3.62
(m, 1H), 3.88–4.03 (m, 2H), 4.22 (dd, 1H, J=14.5, 7.4 Hz), 4.52 (ABq, 2H, J=12 Hz), 7.25 (m, 5H),
7.71–7.73 (m, 2H), 7.82–7.85 (m, 2H); found: C, 70.61; H, 5.11; N, 4.21; C19H17NO4 requires: C, 70.59;
H, 5.25; N, 4.35%.
Acknowledgements
Financial support from CSIR (01/1371/EMR-II/95) and JU (senior research fellowships to D.S.S. and
D.D.) is gratefully acknowledged.
References
1. (a) Babine, R. E.; Bender, S. L. Chem. Rev. 1997, 97, 1359; (b) March, D. R.; Fairlie D. P. In Designing New Antiviral
Drugs for AIDS: HIV-1 Protease and Its Inhibitors; Wise, R., Ed.; R. G. Landes Publishers: Austin, TX, 1996; p. 1; (c)
Takahashi, K. Aspartic Proteineases: Structure, Function, Biology and Biomedical Implications; Plenum Press: New York,
1995; (d) Dutta, A. S. Small Peptides: Chemistry, Biology and Clinical Studies; Elsevier: Amsterdam, 1993; (e) Ager, D.
J.; Prakash, I.; Schaad, D. R. Chem. Rev. 1996, 96, 835; (f) Blaser, H.-U. ibid. 1993, 93, 763; (g) Soai, K.; Niwa, S. ibid.
1992, 92, 833.
2. (a) Beier, C.; Schaumann, E.; Adiwijaja, G. Synlett 1998, 41; (b) Albeck, A.; Estreicher, G. I. Tetrahedron 1997, 53, 5325
and references cited therein.
3. (a) Concellon, J. M.; Bernad, P. L.; Perez-Andres, J. A. J. Org. Chem 1997, 62, 8902; (b) Albeck, A.; Persky, R.
Tetrahedron 1994, 50, 6333.
4. (a) Romeo, S.; Rich, D. H. Tetrahedron Lett. 1994, 35, 4939; (b) Luly, J. R.; Dellaria, J. F.; Plattner, J. J.; Soderquist, J.
L.; Yi, N. J. Org. Chem. 1987, 52, 1487; (c) Ashton, W. T.; Cantone, C. L.; Meurer, L. C.; Tolman, R. L.; Greenlee, W. J.;
Patchett, A. A.; Lynch, R. J.; Schorn, T. W.; Strouse, J. F.; Siegel, P. K. S. J. Med. Chem. 1992, 35, 2103; (d) Albeck, A.;
Persky, R. J. Org. Chem. 1994, 59, 653; (e) Barluenga, J.; Baragana, B.; Concellon, J. M. J. Org. Chem. 1995, 60, 6696;
(f) for a synthesis of ent-1, see Mulzer, J.; Buttelmann, B.; Munch, W. Liebigs Ann. Chem. 1988, 445.
5. (a) Balenovic, K.; Dvornik, D. J. Chem. Soc. 1954, 2976; (b) Balenovic, K.; Cerar, D.; Fuks, Z. ibid. 1952, 3316; (c)
Sengupta, S.; Das, D. Synth. Commun. 1998, 28, 143.
6. For reviews on enantiopure α-amino diazoketones, see (a) Doyle, M. P.; McKervey, M. A. J. Chem. Soc., Chem. Commun.
1997, 983; (b) Ye, T.; McKervey, M. A. Chem. Rev. 1994, 94, 1091.