5908
F. Yokokawa et al. / Tetrahedron Letters 42 (2001) 5903–5908
spectra of micropeptin T-20. The high resolution FAB
mass spectrum was measured by Dr. Akito Nagatsu
(Nagoya City University), to whom the authors’ would
like to give thanks.
M. M. Synth. Commun. 1993, 23, 349–356; (c) Deng, J.;
Hamada, Y.; Shioiri, T.; Matsunaga, S.; Fusetani, N.
Angew. Chem., Int. Ed. Engl. 1994, 33, 1729–1731; (d)
Deng, J.; Hamada, Y.; Shioiri, T. Synthesis 1998, 627–
638.
10. Bartdi, G.; Basco, M.; Marcantoni, E.; Sambri, L.; Tor-
References
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2. Dolastatin 13 was the first isolated peptide containing
Ahp, see: Pettit, G. R.; Kamano, Y.; Herald, C. L.;
Dufresne, C.; Cerny, R. L.; Herald, D. L.; Schmidt, J.
M.; Kizu, H. J. Am. Chem. Soc. 1989, 111, 5015–5017.
3. For recent examples of the isolation of the Ahp-contain-
ing peptides, see: (a) Okano, T.; Sano, T.; Kaya, K.
Tetrahedron. Lett. 1999, 40, 2379–2382; (b) Itou, Y.;
Ishida, K.; Shin, H. J.; Murakami, M. Tetrahedron 1999,
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4. (a) Yokokawa, F.; Sameshima, H.; Shioiri, T. Synlett
2001, 986–988; (b) For a recent review, see: Shioiri, T.;
Hamada, Y. Synlett 2001, 184–201.
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1982, 30, 3147–3153 and references cited therein.
6. Compound 9 was synthesized from the known acid by
treatment with MeI and KHCO3: Grieco, P. A.; Perez-
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4342–4343.
13. The chemical shift of H-6 (l, 5.16 ppm) and C-6 (l, 75.8
ppm) on the Ahp unit in 22 newly appeared and sug-
gested that the C-6 was substituted with O and N.
14. Synthetic 1; a pale yellow solid: [h]2D3 −24.6 (c 0.15,
CH3OH); 1H NMR (500 MHz, CD3OD): l (ppm) 0.87
(3H, t, J=7.4 Hz, Ile-5-H), 0.91 (3H, d, J=6.7 Hz,
Ile-6-H), 1.07–1.15 (1H, m, Ile-4-H), 1.27 (3H, d, J=6.4
Hz, Thr-4-H), 1.28–1.35 (1H, m, Ile-4-H), 1.60–1.66,
1.68–1.75 (2H, m, Ahp-5-H), 1.77–1.89 (2H, m, Ahp-4-H,
Ile-3-H), 1.98–2.04 (1H, m, Tyr-3-H), 2.56–2.66 (1H, m,
Ahp-4-H), 2.66–2.80 (2H, m, Phe(1)-3-H, Phe(2)-3-H),
2.85 (3H, s, NMe), 2.92–2.98 (1H, m, Tyr-3-H), 3.36–3.45
(2H, m, Phe(1)-3-H, Phe(2)-3-H), 3.83 (1H, ddd, J=6.7,
9.4, 12.2 Hz, Ahp-3-H), 4.00–4.07 (1H, m, Ga-3-H),
4.13-4.18 (2H, m, Ga-2,3-H), 4.53 (1H, br, Thr-2-H),
4.65–4.71 (2H, m, Ile-2-H, Phe(1)-2-H), 4.90–4.96 (1H, m,
Tyr-2-H), 5.03–5.06 (1H, m, Phe(2)-2-H), 5.16 (1H, br,
Ahp-6-H), 5.46–5.52 (1H, m, Thr-3-H), 6.82 (2H, d,
J=8.5 Hz, Tyr-6,8-H), 6.89 (2H, d, J=7.1 Hz, Tyr-5,9-
H), 7.08–7.21 (10H, m, C6H5×2); 13C NMR (500 MHz,
CD3OD): l (ppm) 11.6, 16.7, 18.2, 22.4, 26.2, 30.6, 31.6,
34.3, 36.4, 37.4, 39.1, 50.8, 52.5, 55.8, 56.1, 57.4, 63.2,
68.3, 73.5, 73.7, 75.8, 116.7, 127.5, 127.7, 129.1, 129.4,
129.5, 130.1, 130.7, 131.8, 137.7, 139.0, 157.7, 190.9,
171.2, 171.5, 172.9, 173.3, 174.3, 174.6; HRFABMS (m-
nitrobenzyl alcohol) calcd for C46H57N6Na2O15P [M+H]+:
1011.3492. Found: 1011.3533.
8. Ishizumi, K.; Koga, K.; Yamada, S. Chem. Pharm. Bull.
1968, 16, 492–497.
9. (a) Chen, S.; Xu, J. Tetrahedron Lett. 1991, 32, 6711–
6714; (b) Dudash, Jr., J.; Jiang, J.; Mayer, S. C.; Joullie,
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