K. Sato et al.
Bull. Chem. Soc. Jpn. Vol. 86, No. 1 (2013)
117
Boc-Ala-OSu (172 mg, 0.6 mmol) as described for 9a; yield,
from 9d (355 mg, 0.4 mmol) and HOSu (92 mg, 0.8 mmol) was
treated with TFA to afford 11d (407 mg, 100%, Rf1 0.48, and
Rf2 0.11), which was cyclized in anhydrous pyridine (128 mL)
as described for 12a. After usual work-up including gel
filtration with Sephadex LH-20, 12d was obtained as colorless
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366 mg (90%); mp 120-122 °C; ½¡ꢀD 11.8° (c 0.8, MeOH); Rf1
0.22, Rf2 0.15, Rf3 0.76, and Rf4 0.94. Found: C, 57.40; H, 7.63;
N, 10.25%. Calcd for C39H61N6O10Cl¢0.5H2O: C, 57.24; H,
7.64; N, 10.27%.
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cyclo[-Ala-D-Leu-D-Lys(Cl-Z)-D-Leu-Pro-]2 (12b). Ac-
tive ester 10b (357 mg, 98%, Rf1 0.73, and Rf2 0.23) prepared
from 9b (324 mg, 0.4 mmol) and HOSu (92 mg, 0.8 mmol) was
treated with TFA to afford 11b (395 mg, 100%, Rf1 0.42, and
Rf2 0.08), which was cyclized in anhydrous pyridine (126 mL)
as described for 12a. After usual work-up including gel
filtration with Sephadex LH-20, 12b was obtained as colorless
powder; yield, 175 mg (57%); mp 145-147 °C; ½¡ꢀD 23.6° (c
0.2, MeOH); Rf1 0.82, Rf2 0.33, Rf3 0.98, and Rf4 0.96. Found:
C, 61.41; H, 7.13; N, 10.73%. Calcd for C80H110N12O14Cl2¢
2H2O: C, 61.17; H, 7.32; N, 10.70%.
cyclo[-Phe-D-Leu-D-Lys-D-Leu-Pro-]2¢2HCl (1d¢2HCl).
Compound 12d (77 mg, 0.05 mmol) was hydrogenated as
described for 1a; yield 65 mg (100%); mp 215-220 °C;
24
24
powder; yield, 135 mg (50%); mp 227-228 °C; ½¡ꢀD 65.0° (c
½¡ꢀD 1.9° (c 0.4, MeOH); Rf1 0.00, Rf2 0.00, Rf3 0.74, and
0.4, MeOH); Rf1 0.75, Rf2 0.31, Rf3 0.91, and Rf4 0.90. Found:
C, 59.08; H, 7.49; N, 12.01%. Calcd for C68H102N12O14Cl2: C,
59.08; H, 7.44; N, 12.16%.
Rf4 0.46; MS (FAB), m/z 1196 (C64H112N12O10, M+). Amino
acid ratios in acid hydrolysate: Phe (0.90), Lys (1.00), Leu
(1.91), and Pro (1.00). Found: C, 56.65; H, 8.04; N, 12.04%.
Calcd for C64H112N12O10¢2HCl¢5H2O: C, 56.50; H, 8.30;
N, 12.35%.
cyclo[-Ala-D-Leu-D-Lys-D-Leu-Pro-]2¢2HCl (1b¢2HCl).
Compound 12b (97 mg, 0.07 mmol) was hydrogenated as
24
described for 1a; yield 75 mg (96%); mp 290-293 °C; ½¡ꢀD
cyclo[-Cha-D-Leu-D-Lys-D-Leu-Pro-]2¢2HCl (1e¢2HCl).
Compound 1d¢2HCl (64 mg, 0.05 mmol) dissolved in AcOH
(5 mL) was hydrogenated in the presence of Pt-black (ca 150
mg) for 7 h at room temperature. After filtration of catalyst, the
filtrate was evaporated and the residue was crystallized from
46.2° (c 0.7, MeOH); Rf1 0.00, Rf2 0.00, Rf3 0.57, and Rf4 0.27;
MS (FAB), m/z 1044 (C52H92N12O10, M+). Amino acid ratios
in acid hydrolyzate: Ala (0.96), Lys (1.06), Leu (2.01), and
Pro (1.00). Found: C, 52.59; H, 8.37; N, 13.90%. Calcd for
C52H92N12O10¢2HCl¢4H2O: C, 52.47; H, 8.64; N, 14.12%.
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MeOH-ether; yield 62 mg (97%); mp 220-225 °C; ½¡ꢀD 1.4°
Boc-Leu-D-Leu-D-Lys(Cl-Z)-D-Leu-Pro-OH
(9c).
(c 0.5, MeOH); Rf1 0.00, Rf2 0.00, Rf3 0.75, and Rf4 0.47; MS
(FAB), m/z 1208 (C64H112N12O10, M+). Found: C, 58.56; H,
8.88; N, 12.51%. Calcd for C64H112N12O10¢2HCl¢2H2O: C,
58.30; H, 9.02; N, 12.75%.
Compound 8¢HCl (270 mg, 0.4 mmol) was coupled with
Boc-Leu-OSu (149 mg, 0.48 mmol) as described for 9a; yield,
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249 mg (73%); mp 127-130 °C; ½¡ꢀD 10.4° (c 0.6, MeOH); Rf1
0.35, Rf2 0.22, Rf3 0.81, and Rf4 0.88. Found: C, 58.85; H, 7.95;
N, 9.79%. Calcd for C42H67N6O10Cl: C, 59.24; H, 7.93; N,
9.87%.
Boc-Gly-D-Leu-D-Lys(Cl-Z)-D-Leu-Pro-OH
(9f).
Compound 8¢HCl (270 mg, 0.4 mmol) was coupled with
Boc-Gly-OSu (122 mg, 0.45 mmol) as described for 9a; yield,
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cyclo[-Leu-D-Leu-D-Lys(Cl-Z)-D-Leu-Pro-]2 (12c). Ac-
tive ester 10c (240 mg, 100%, Rf1 0.78, and Rf2 0.29) prepared
from 9c (213 mg, 0.25 mmol) and HOSu (58 mg, 0.5 mmol)
was treated with TFA to afford 11c (252 mg, 100%, Rf1 0.49,
and Rf2 0.14), which was cyclized in anhydrous pyridine (80
mL) as described for 12a. After usual work-up including gel
filtration with Sephadex LH-20, 12c was obtained as colorless
290 mg (91%); mp 115-119 °C; ½¡ꢀD 23.7° (c 0.4, MeOH); Rf1
0.22, Rf2 0.09, Rf3 0.78, and Rf4 0.80. Found: C, 56.78; H, 7.49;
N, 10.40%. Calcd for C38H59N6O10Cl¢0.5H2O: C, 56.74; H,
7.52; N, 10.45%.
cyclo[-Gly-D-Leu-D-Lys(Cl-Z)-D-Leu-Pro-] (12f-mono-
mer).
Active ester 10f (289 mg, 98%, Rf1 0.77, and Rf2
0.23) prepared from 9f (262 mg, 0.33 mmol) and HOSu (76
mg, 0.66 mmol) was treated with TFA to afford 11f (295 mg,
100%, Rf1 0.34, and Rf2 0.02), which was cyclized in anhydrous
pyridine (101 mL) as described for 12a. After usual work-up
including gel filtration with Sephadex LH-20, 12f-monomer
was obtained as colorless powder; yield, 148 mg (68%); mp
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powder; yield, 63 mg (34%); mp 237-241 °C; ½¡ꢀD 36.1° (c
0.2, MeOH); Rf1 0.81, Rf2 0.32, Rf3 0.98, and Rf4 0.98. Found:
C, 59.91; H, 7.81; N, 11.24%. Calcd for C74H114N12O14Cl2¢
H2O: C, 59.86; H, 7.88; N, 11.32%.
cyclo[-Leu-D-Leu-D-Lys-D-Leu-Pro-]2¢2HCl (1c¢2HCl).
Compound 12c (44 mg, 0.03 mmol) was hydrogenated as
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150-151 °C; ½¡ꢀD 76.9° (c 0.6, MeOH); Rf1 0.48, Rf2 0.07, Rf3
24
described for 1a; yield 36 mg (100%); mp 230-233 °C; ½¡ꢀD
0.73, and Rf4 0.66. Found: C, 56.95; H, 7.18; N, 12.05%. Calcd
for C33H49N6O7Cl¢H2O: C, 57.01; H, 7.39; N, 12.09%.
4.7° (c 0.2, MeOH); Rf1 0.00, Rf2 0.00, Rf3 0.75, and Rf4
0.44; MS (FAB), m/z 1129 (C58H104N12O10, M+). Amino acid
ratios in acid hydrolysate: Leu (2.87), Lys (1.01), and Pro
(1.00). Found: C, 54.21; H, 8.82; N, 12.83%. Calcd for
C58H104N12O10¢2HCl¢4.5H2O: C, 54.27; H, 9.03; N, 13.10%.
cyclo[-Gly-D-Leu-D-Lys-D-Leu-Pro-]¢HCl
(1f-mono-
mer¢HCl). Compound 12f-monomer (68 mg, 0.05 mmol)
was hydrogenated as described for 1a; yield 55 mg (100%); mp
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187-192 °C; ½¡ꢀD 104.9° (c 0.6, MeOH); Rf1 0.00, Rf2 0.00,
Boc-Phe-D-Leu-D-Lys(Cl-Z)-D-Leu-Pro-OH
(9d).
Rf3 0.67, and Rf4 0.37; MS (FAB), m/z 508 (C25H44N6O5, M+).
Amino acid ratios in acid hydrolysate: Gly (0.94), Lys (1.00),
Leu (1.90), and Pro (1.00). Found: C, 52.06; H, 8.22; N,
14.38%. Calcd for C25H44N6O5¢HCl¢1.5H2O: C, 52.48; H,
8.46; N, 14.69%.
Compound 8¢HCl (337 mg, 0.5 mmol) was coupled with
Boc-Phe-OSu (218 mg, 0.6 mmol) as described for 9a; yield,
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383 mg (86%); mp 198-200 °C; ½¡ꢀD 22.6° (c 0.4, MeOH); Rf1
0.29, Rf2 0.17, Rf3 0.76, and Rf4 0.85. Found: C, 60.20; H, 7.36;
N, 9.34%. Calcd for C45H65N6O10Cl¢0.5H2O: C, 60.42; H,
7.44; N, 9.40%.
Boc-D-Ala-D-Leu-D-Lys(Cl-Z)-D-Leu-Pro-OH (9g).
Compound 8¢HCl (337 mg, 0.5 mmol) was coupled with
Boc-D-Ala-OSu (172 mg, 0.6 mmol) as described for 9a; yield,
cyclo[-Phe-D-Leu-D-Lys(Cl-Z)-D-Leu-Pro-]2 (12d). Ac-
tive ester 10d (406 mg, 100%, Rf1 0.77, and Rf2 0.37) prepared
24
370 mg (91%); mp 122-124 °C; ½¡ꢀD 34.5° (c 0.5, MeOH); Rf1