The Synthesis of Two Analogues of Eponemycin
FULL PAPER
before being recooled to 0 °C and quenched with brine (30 mL).
The resulting mixture was extracted twice with diethyl ether
(10 mL) and twice with EtOAc (10 mL). The combined organic
layers were then successively washed with 2 % aqueous KHSO4,
ϩ H]ϩ, 411.2 [M ϩ Na]ϩ, 427.2 [M ϩ K]ϩ, 799.4 [2M ϩ Na]ϩ.
HRMS (ES, Na): m/z ϭ 411.18959 [M ϩ Na]ϩ, calcd. for
C21H28N2O5Na: m/z ϭ 411.18959. C21H28N2O5 (338.46): calcd. C
64.93, H 7.27, N 7.21, O 20.59; found C 64.86, H 7.57, N 6.97, O
with saturated aqueous NaHCO3 and with brine, dried with 20.24. Chiral HPLC (3 ϫ 100 mm analytical column, Waters X-
Na2SO4, filtered and concentrated in vacuo. Gradient flash column
chromatography (SiO2, EtOAc/cyclohexane, 2:3, EtOAc/cyclohex-
Terra; mobile phase: 75 % water and 25 % acetonitrile; flow rate ϭ
0.8 mL/min; detection, 270 nm; temperature, room temperature; re-
ane, 1:1) afforded 4 (35 mg, 55 %) as a glassy solid. [α]D20 ϭ ϩ11.3 tention time ϭ 26.61Ϫ30.32 min): de ϭ 48 %.
(c ϭ 1.15, CHCl3). 1H NMR (300 MHz, CDCl3): δ ϭ 7.63 (dd,
3
3J5ЈЈЈ,3ЈЈЈ ϭ 0.6 Hz, J5ЈЈЈ,4ЈЈЈ ϭ 1.7 Hz, 1 H, 5ЈЈЈ-H), 7.33 (dd,
N-[(2E,4E)-6-Methylhepta-2,4-dienoyl][(2S)-seryl]glycine
Methyl
3
3J3ЈЈЈ,5ЈЈЈ ϭ 0.6 Hz, J3ЈЈЈ,4ЈЈЈ ϭ 3.6 Hz, 1 H, 3ЈЈЈ-H), 7.14 (d, 3J ϭ
Ester: PyBOP (347 mg, 0.66 mmol), HOBt (86.1 mg, 0.60 mmol)
and acid 13 (150 mg, 0.66 mmol) were added successively to a sus-
pension of glycine methyl ester hydrochloride (76.1 mg, 0.60 mmol)
in DMF (7 mL). The resulting mixture was cooled to 0 °C and
treated with NEM (77.1 µL, 0.60 mmol). The reaction mixture was
stirred for 1 h at 0 °C and for 2 h at room temperature before being
recooled to 0 °C and quenched with brine (60 mL). The resulting
mixture was extracted twice with diethyl ether (20 mL) and twice
with EtOAc (20 mL). The combined organic layers were then
washed successively with 2 % aqueous KHSO4, saturated aqueous
NaHCO3 and brine, dried with Na2SO4, filtered and concentrated
in vacuo. Flash column chromatography (SiO2, EtOAc/cyclohex-
ane, 7:3) afforded the coupling product (100 mg, 51 %) as a light
3
3
7.5 Hz, 1 H, NH), 6.57 (dd, J4ЈЈЈ,5ЈЈЈ ϭ 1.7 Hz, J4ЈЈЈ,3ЈЈЈ ϭ 3.6 Hz,
3
1 H, 4ЈЈЈ-H), 6.51 (d, J ϭ 7.1 Hz, 1 H, NH), 5.37 (m, 1 H, 1ЈЈ-H),
4.82 (s, 1 H, 4ЈЈ-Ha), 4.74 (s, 1 H, 4ЈЈ-Hb), 4.51 (m, 1 H, 1Ј-H), 4.00
(dd, J2Јa,1Ј ϭ 3.6 Hz, J2Јa,2Јb ϭ 11.4 Hz, 1 H, 2Ј-Ha), 3.57 (dd,
3J2Јb,1Ј ϭ 5.6 Hz, 2J2Јb,2Јa ϭ 11.4 Hz, 1 H, 2Ј-Hb), 3.56 (s, 1 H, OH),
2.59 (dd, 3J2ЈЈa,1ЈЈ ϭ 4.3 Hz, 2J2ЈЈa,2ЈЈb ϭ 14.2 Hz, 1 H, 2ЈЈ-Ha), 2.35
3
2
3
2
(dd, J2ЈЈb,1ЈЈ ϭ 9.57 Hz, J2ЈЈb,2ЈЈa ϭ 14.2 Hz, 1 H, 2ЈЈ-Hb), 2.20 (t,
3J2,3 ϭ 7.7 Hz, 2 H, 2-H), 1.75 (s, 3 H, 5-H), 1.51 (m, 3 H, 3-H
and 6-H), 1.18 (m, 2 H, 4-H), 1.15 (m, 2 H, 5-H), 0.83 (d, 3J ϭ
6.6 Hz, 6 H, CH3CHCH3) ppm. 13C NMR (75 MHz, CDCl3): δ ϭ
187.31 (CϭOC2ЈЈЈ), 174.16 (CϭONH), 171.36 (C-1), 151.30 (C-
2ЈЈЈ), 147.62 (C-5ЈЈЈ), 140.50 (C-3ЈЈ), 119.39 (C-3ЈЈЈ), 115.20 (C-4ЈЈ),
113.14 (C-4ЈЈЈ), 63.35 (C-2Ј), 54.00 (C-1Ј), 53.58 (C-1ЈЈ), 40.69 (C-
2ЈЈ), 38.97 (C-4 or C-5), 36.89 (C-2), 28.18 (C-6), 27.41 (C-4 or C-
5), 26.17 (C-3), 22.96 (CH3CHCH3), 22.33 (C-5ЈЈ) ppm. MS (ES,
Na): m/z ϭ 393.2 [M ϩ H]ϩ, 415.2 [M ϩ Na]ϩ, 431.2 [M ϩ K]ϩ.
HRMS (ES, Na): m/z ϭ 415.22089 [M ϩ Na]ϩ, calcd. for
C21H32N2O5Na: m/z ϭ 415.22089. C21H32N2O5 (392.49): calcd. C
64.26, H 8.22, N 7.14, O 20.38; found C 64.03, H 8.44, N 7.17, O
20.43. Chiral HPLC (3 ϫ 100 mm analytical column, Waters X-
Terra, mobile phase: 72 % water and 28 % acetonitrile; flow rate ϭ
0.8 mL/min; detection wavelength ϭ 280 nm; room temperature;
retention time ϭ 20.73 min): de ϭ 96 %.
1
orange oil. H NMR (300 MHz, CDCl3): δ ϭ 7.39 (s, 1 H, NH),
3
7.20 (m, 1 H, 3ЈЈ-H), 6.74 (d, J ϭ 7.2 Hz, 1 H, NH), 6.12Ϫ6.09
3
(m, 2 H, 4ЈЈ-H and 5ЈЈ-H), 5.87 (d, J2ЈЈ,3ЈЈ ϭ 15.0 Hz, 1 H, 2ЈЈ-H),
3
4.60 (m, 1 H, 2-ЈH), 4.17 (dd, J3Јa,2Ј ϭ 3.1 Hz, 2J3Јa,3Јb ϭ 11.6 Hz,
3
1 H, 3Ј-Ha), 4.04 (d, J ϭ 5.7 Hz, 2 H, 2-H), 3.75 (s, 3 H, CH3O),
3
2
3.70 (dd, J3Јb,2Ј ϭ 4.9 Hz, J3Јb,3Јa ϭ 11.6 Hz, 1 H, 3Ј-Hb), 3.14 (s,
1 H, OH), 2.42 (m, 1 H, 6ЈЈ-H), 1.04 (d, 3J ϭ 6.8 Hz, 6 H,
CH3CHCH3) ppm. 13C NMR (75 MHz, CDCl3): δ ϭ 172.33 (C-
1Ј), 170.77 (C-1ЈЈ), 167.95 (C-1), 151.91 (C-5ЈЈ), 143.97 (C-3ЈЈ),
125.89 (C-4ЈЈ), 121.14 (C-2ЈЈ), 63.42 (C-3Ј), 54.62 (C-2Ј), 53.19
(CH3O), 41.89 (C-2), 32.2 (C-6ЈЈ), 22.49 (CH3CHCH3) ppm. MS
(ES, Na): m/z ϭ 321.3 [M ϩ Na]ϩ, 322.3 [MH ϩ Na]ϩ, 337.3 [M
ϩ K]ϩ. HRMS (ES, Na): m/z ϭ 321.14264 [M ϩ Na]ϩ, calcd. for
(S,S,E)-Compound 5: PyBOP (265.1 mg, 0.51 mmol), HOBt
(42.56 mg, 0.32 mmol) and acid 13 (98.1 mg, 0.41 mmol) were ad- C14H22N2O5Na: m/z ϭ 321.14264. C14H22N2O5 (298.34): calcd. C
ded successively to a suspension of 19 (68 mg, 0.32 mmol) in DMF
56.36, H 7.43, N 9.39, O 26.81; found C 56.25, H 7.42, N 9.69, O
(5 mL). The resulting dark orange mixture was cooled to 0 °C and 26.64. Chiral HPLC (analytical column, Chiralpak AD; mobile
treated with NEM (40.4 µL, 0.32 mmol). The reaction mixture was
phase: 60 % hexane and 40 % 2-propanol; flow rate ϭ 1 mL/min;
stirred at 0 °C for 1 h and at room temperature for 30 min before detection wavelength ϭ 259 nm; room temperature; retention
being recooled to 0 °C, at which point is was quenched with brine
(60 mL). The resulting mixture was extracted twice with diethyl
ether (20 mL) and twice with EtOAc (20 mL). The combined or-
ganic layers were then washed successively with 2 % aqueous
KHSO4, saturated aqueous NaHCO3 and brine, dried with
Na2SO4, filtered and concentrated in vacuo. Gradient flash column
chromatography (SiO2, EtOAc/cyclohexane, 2:3, EtOAc/cyclohex-
ane, 1:1) afforded 5 (66 mg, 54 %) as a glassy solid. 1H NMR
time ϭ 7.69Ϫ14.72 min): de ϭ 58 %.
Acknowledgments
We are grateful to Servier Laboratories, Institut Curie (‘‘Pro-
´
`
´
grammme Incitatif Cooperatif Angiogenese’’) and the Societe de
´
Chimie Therapeutique (scholarship for BB) for generous financial
3
support.
(300 MHz, CDCl3): δ ϭ 7.63 (d, J5ЈЈЈ,4ЈЈЈϭ 1.7 Hz, 1 H, 5ЈЈЈ-H),
3
7.33 (d, J3ЈЈЈ,4ЈЈЈ ϭ 3.6 Hz, 1 H, 3ЈЈЈ-H), 7.24 (m, 1 H, 3-H), 7.13
3
3
(d, J ϭ 7.6 Hz, 1 H, NH), 6.57 (dd, J4ЈЈЈ,5ЈЈЈ ϭ 1.7 Hz, 3J4ЈЈЈ,3ЈЈЈ
ϭ
[1]
K. Sugawara, M. Hatori, Y. Nishiyama, K. Tomita, H. Kamei,
3
3.6 Hz, 1 H, 4ЈЈЈ-H), 6.46 (d, J ϭ 6.4 Hz, 1 H, NH), 6.08 (m, 2
M. Konishi, T. Oki, J. Antibiot. 1990, 43, 1, 8Ϫ18.
T. Oikawa, M. Hasegawa, M. Shimamura, H. Ashino, S. Mur-
3
[2]
H, 4.5-H), 5.79 (d, J2,3 ϭ 14.9 Hz, 1 H, 2-H), 5.37 (m, 1 H, 1ЈЈ-
H), 4.80 (s, 1 H, 4ЈЈHa), 4.71 (s, 1 H, 4ЈЈ-Hb), 4.57 (m, 1 H, 1Ј-H),
4.11 (m, 1 H, 2Ј-Ha), 3.46 (m, 1 H, 2Ј-Hb), 3.38 (sl, 1 H, OH), 2.61
ota, I. Morita, Biochem. Biophys. Res. Commun. 1991, 181,
1070Ϫ1076.
[3]
(dd, J2ЈЈa,1ЈЈ ϭ 4.3 Hz, J2ЈЈa,2ЈЈb ϭ 14.0 Hz, 1 H, 2ЈЈ-Ha), 2.33 (m,
3
2
L. Meng, B. H. B. Kwok, N. Sin, C. M. Crews, Cancer Research
1999, 59, 2798Ϫ2801.
M. Groll, K. B. Kim, N. Kairies, R. Huber, C. M. Crews, J.
2 H, 6-H and 2ЈЈ-Hb), 1.74 (s, 3 H, 5ЈЈ-H), 1.02 (d, J ϭ 6.7 Hz, 6
3
[4]
H, CH3CHCH3) ppm. 13C NMR (75 MHz, CDCl3): δ ϭ 187.60
(CϭOC2ЈЈЈ), 171.61 (C-1), 167.52 (CϭONH), 151.55 (C-5), 151.37
(C-2ЈЈЈ), 147.90 (C-5ЈЈЈ), 143.47 (C-3), 140.71 (C-3ЈЈ), 125.97 (C-4),
121.56 (C-2), 119.71 (C-3ЈЈЈ), 115.52 (C-4ЈЈ), 113.38 (C-4ЈЈЈ), 63.61
(C-2Ј), 54.57 (C-1Ј), 53.85 (C-1ЈЈ), 40.99 (C-2ЈЈ), 32.14 (C-6), 22.63
(C-5ЈЈ), 22.48 (CH3CHCH3) ppm. MS (ES, Na): m/z ϭ 389.2 [M
Am. Chem. Soc. 2000, 122, 1237Ϫ1238.
N. Sin, K. B. Kim, M. Elofsson, L. Meng, H. Auth, B. H. B.
[5]
Kwok, C. M. Crews, Bioorganic & Medicinal Chemistry Letters
1999, 9, 2283Ϫ2288.
P. C. Brooks, A. M. Montgomery, M. Rosenfeld, R. A. Reis-
[6]
feld, T. Hu, G. Klier, D. A. Cherest, Cell 1994, 79, 1157Ϫ1164.
Eur. J. Org. Chem. 2003, 4561Ϫ4568
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4567