(1H, m, Trp α-H), 4.99 (1H, d, J 12.6, Z-HH), 5.02 (1H, d, J 12.1,
Z-HH ), 6.90–6.97 (3H, m, 3 × ar. CH), 6.99–7.05 (3H, m, 3 × ar.
CH), 7.08 (2H, s, 2 × ar. CH), 7.13 (1H, s, ar. CH), 7.27–7.37
(8H, m, 8 × ar. CH), 7.38–7.47 (7H, m, Ala NH and 6 × ar.
CH), 7.51 (1H, d, J 7.6, ar. CH), 7.56 (2H, t, J 7.5, 2 × ar. CH),
7.56–7.60 (1H, m, NH), 7.61–7.67 (5H, m, 4 × ar. CH and THF
NH), 7.71 (1H, d, J 7.3, NH), 7.85 (1H, d, J 6.9, Leu NH), 7.91
(1H, d, J 9.2, NH), 7.98 (1H, d, J 7.3, NH), 8.08 (1H, t, J 5.8,
AE NH), 8.11–8.18 (2H, m, NH), 8.25–8.36 (3H, m, Trp NH),
10.73–10.78 (2H, m, indole NH), 10.82 (1H, s, indole NH);
HPLC: 11.8 min (M4); m/z (ESI): 1933.8 (M ϩ Naϩ.
C105H142N16NaO16Si requires 1934.0).
B: acetonitrile–isopropanol 2 : 1 ϩ 0.1% TFA; 14 ml minϪ1).
Treatment of the collected fractions according to GP 6 gave
36.0 mg (9.1 µmol, 61%) of pure diamide 7 as a colourless solid.
δH(500 MHz; DMSO-d6; Me4Si) 0.40 (6H, d, J 6.6, 2 × Leu
δ-H3), 0.54 (6H, d, J 6.4, 2 × Leu δ-H3), 0.58 (6H, d, J 6.4, 2 × Leu
δ-H3), 0.65 (12H, d, J 6.0, 4 × Leu δ-H3), 0.72 (6H, d, J 6.19, 2 ×
Leu δ-H3), 0.74–0.82 (30H, m, 10 × Val γ-H3), 0.83–0.87 (18H,
m, 6 × Val γ-H3), 0.89 (6H, d, J 6.6, 2 × THF 2Ј-H3), 0.98 (18H,
s, 6 × t-Bu-H3), 0.99–1.05 (2H, m, 2 × Leu γ-H), 1.09–1.38
(26H, m, 4 × Ala β-H3, 4 × Leu β-H2, 2 × THF 4- HH, 2 × THF
3-HH and 2 × Leu γ-H), 1.39–1.59 (8H, m, 2 × Leu β-H2, 2 ×
THF 3-HH and 2 × Val β-H), 1.61–1.68 (2H, m, 2 × Leu γ-H),
1.72–1.80 (2H, m, 2 × THF 4-HH ), 1.90–2.06 (6H, m, 6 × Val
β-H), 2.36–2.47 (4H, m, succ 2-H2 and 3-H2), 2.76–2.84 (2H, m,
2 × Trp β-HH), 2.85–2.95 (4H, m, 4 × Trp β-HH), 3.14–3.31
(6H, m, 6 × Trp β-HH ), 3.52 (2H, s, 2 × Gly α-HH), 3.61–3.68
(6H, m, 2 × AE 2-H2 and 2 × Gly α-HH ), 3.69–3.78 (4H, m, 2 ×
THF 5-H and 2 × Leu α-H), 3.81–3.88 (2H, m, 2 × Leu α-H),
3.89–3.97 (2H, m, 2 × THF 1Ј-H), 4.07–4.13 (2H, m, 2 × Val α-
H), 4.15–4.33 (14H, m, 6 × Val α-H, 2 × THF 2-H, 4 × Ala α-H
and 2 × Leu α-H), 4.39–4.51 (4H, m, 4 × Trp α-H), 4.54–4.61
(2H, m, 2 × Trp α-H), 6.90–6.97 (6H, m, 6 × ar. CH), 6.99–7.06
(6H, m, 6 × ar. CH), 7.08 (4H, s, 4 × ar. CH), 7.13 (2H, s, 2 × ar.
CH), 7.30 (6H, d, J 8.0, 6 × ar. CH), 7.37–7.47 (12H, m, 12 × ar.
CH), 7.51 (2H, d, J 7.8, 2 × ar. CH), 7.56 (4H, t, J 6.5, 4 × ar.
CH), 7.59–7.67 (12H, m, 8 × ar. CH, NH and THF NH), 7.68–
7.73 (2H, m, 2 × NH), 7.82–7.94 (8H, m, 6 × NH and 2 × Leu
NH), 8.00–8.11 (6H, m, 4 × NH and 2 × AE NH), 8.12–8.18
(2H, m, 2 × NH), 8.21–8.39 (8H, m, 6 × Trp NH and 2 × Gly
NH), 10.73–10.79 (4H, m, 4 × indole NH), 10.82 (2H, s, 2 ×
indole NH); HPLC: 18.1 min (M4); m/z (ESI): 1998.0 (M ϩ
2Naϩ. C212H298N36Na2O34Si requires 1997.1).
H-Ala-D-Leu-Ala-D-Val-Val-D-Val-Trp-D-THF-D-Leu-Trp-D-
Leu-Trp-2-(t-butyldiphenylsilyloxy)-ethylamide 33a. 200 mg
(104 µmol) of peptide 33 were N-deprotected according to GP
2A (EtOH, 50 ЊC). After filtration and evaporation FCC (25 g,
CHCl3–MeOH–NH3(conc.) 100 : 10 : 1) gave 125 mg (70.0
µmol, 67%) of amine 33a. Rf = 0.15 (CHCl3–MeOH–HCO2H
100 : 10 : 1). HPLC: 9.9 min (250 × 4 mm Dynamax C8,
60 100% B in 25 min, A: H2O ϩ 0.1% TFA; B:acetonitrile–
isopropanol 2 : 1 ϩ 0.1% TFA; 0.7 ml minϪ1). m/z (ESI): 1799.7
(M ϩ Naϩ. C97H136N16NaO14Si requires 1800.0).
Succ-1-(1Ј-t-butyldiphenylsilyloxy-10,11[D-THF]-gramicidin
A)-4-(Val-Gly-OMe)-diamide 34. 23.5 mg (44.0 µmol) of benzyl
ester 17 were C-deprotected according to GP 2A. The crude
carboxylic acid and 40.0 mg (22.5 µmol) of amine 33a were then
collected and coupled according to GP 4 (1.0 m, 3 h). After
aqueous work-up FCC (4 g, 4% MeOH in CHCl3 6% MeOH
in CHCl3 ϩ 0.6% HCO2H) gave 35.0 mg (16.0 mmol, 73%) of
pure diamide 34 as a colourless solid. Rf = 0.35 (CHCl3–
MeOH–HCO2H 100 : 10 : 1); δH (500 MHz; DMSO-d6; Me4Si)
0.40 (3H, d, J 6.6, Leu δ-H3), 0.55 (3H, d, J 6.4, Leu δ-H3), 0.58
(3H, d, J 6.4, Leu δ-H3), 0.65 (6H, d, J 6.2, 2 × Leu δ-H3), 0.72
(3H, d, J 6.6, Leu δ-H3), 0.74–0.82 (15H, m, 5 × Val γ-H3),
0.83–0.93 (18H, m, 5 × Val γ-H3 and THF 2Ј-H3), 0.98 (9H, s,
3 × t-Bu-H3), 0.99–1.04 (1H, m, Leu γ-H), 1.08–1.34 (13H, m,
2 × Ala β-H3, THF 3-HH and 4-HH, 2 × Leu β-H2 and Leu
γ-H), 1.41–1.60 (4H, m, Leu β-H2, THF 3-HH and Val β-H),
1.61–1.69 (1H, m, Leu γ-H), 1.71–1.81 (1H, m, THF 4-HH),
1.91–2.07 (4H, m, 4 × Val β-H), 2.36–2.47 (4H, m, succ 3-H2
and 4-H2), 2.75–2.83 (1H, m, Trp β-HH), 2.85–2.96 (2H, m, 2 ×
Trp β-HH), 3.13–3.30 (5H, m, 3 × Trp βHH and AE 2-H2), 3.62
(3H, s, OCH3), 3.65 (2H, t, J 6.5, AE 1-H2), 3.67–3.89 (6H, m, 2
× Gly α-H2, THF 5-H and Leu αCH), 3.90–3.96 (1H, m, THF
1Ј-H), 4.06–4.34 (10H, m, 5 × Val α-H, 2 × Leu α-H, 2 × Ala
α-H, and THF 2-H), 4.40–4.50 (2H, m, 2 × Trp α-H), 4.54–4.61
(1H, m, Trp α-H), 6.90–6.97 (3H, m, 3 × ar. CH), 6.99–7.05
(3H, m, 3 × ar. CH), 7.08 (2H, s, 2 × ar. CH), 7.13 (1H, d, J 1.4,
ar. CH), 7.28–7.32 (3H, m, 3 × ar. CH), 7.38–7.47 (6H, m,
6 × ar. CH), 7.51 (1H, d, J 7.6, ar. CH), 7.56 (2H, t, J 7.1, ar.
CH), 7.59–7.64 (5H, m, 4 × CH and NH), 7.65 (1H, d, J 8.5,
THF NH), 7.71 (1H, d, J 6.7, NH), 7.83–7.93 (4H, m, Leu NH
and 3 × NH), 7.96 (1H, d, J 8.9, NH), 8.05–8.11 (2H, m, 2 ×
NH), 8.12–8.17 (1H, m, NH), 8.20–8.37 (4H, m, 4 × NH), 8.39
(1H, t, J 5.84, Gly NH), 10.75 (1H, s, indole NH), 10.77 (1H, s,
indole NH), 10.82 (1H, s, indole NH). HPLC: 9.8 min (M4); m/z
(ESI): 2226.4 (M ϩ Naϩ. C116H166N20NaO21Si requires 2226.2).
Succ-1-(10,11[D-THF-]-gA-TBDPS)-4-(gA-TBDPS) 8. 70.0 mg
(29.6 µmol) of methyl ester 35 were C-deprotected according to
GP 1. The crude carboxylic acid and 40.0 mg (22.5 µmol)
of amine 33a were collected and coupled according to GP 5
(1.0 m, 12 h). After aqueous work-up 81.0 mg of crude
diamide 8 were obtained and purified by preparative HPLC
(250 mm Rainin C 4, 80 90% B in 10 min, then 90 100% B
in 15 min. A: H2O ϩ 0.1% TFA; B: acetonitrile–isopropanol
2 : 1 ϩ 0.1% TFA; 14 ml minϪ1). Treatment of the collected
fractions according to GP 6 gave 43.0 mg (10.5 µmol, 46%) of
pure diamide 8 as a colourless solid. δH (500 MHz; DMSO-d6;
Me4Si) 0.40 (3H, d, J 6.4, Leu δ-H3), 0.49 (6H, d, J 6.4, 2 × Leu
δ-H3), 0.51–0.62 (15H, m, 5 × Leu δ-H3), 0.61–0.68 (9H, m, 3 ×
Leu δ-H3), 0.72 (3H, d, J 6.2, Leu d-H3), 0.74–0.91 (54H, m, 2 ×
Leu δ-H3 and 16 × Val γ-H3), 0.92–0.95 (3H, m, THF 2Ј-H3),
0.97 (9H, s, 3 × t-Bu-H3), 0.98 (9H, s, 3 × t-Bu H3), 1.09–1.32
(26H, m, 4 × Ala β-H3, 5 × Leu β-H2 and 4 × Leu γ-H), 1.42–
1.59 (8H, m, 2 × Leu β-H2, 2 × Val β-H, THF 4-HH and THF
3-HH), 1.61–1.67 (1H, m, Leu γ-H), 1.74–1.82 (1H, m, Leu
γ-H), 1.90–2.05 (7H, m, 6 × Val β-H and Leu γ-H), 2.19 (1H, t,
J 7.3, THF 3-HH), 2.25–2.32 (1H, m, THF 4-HH ), 2.36–2.47
(4H, m, succ 2-H2 and 3-H2) 2.74–2.95 (6H, m, 3 × Trp β-H2),
3.06–3.29 (8H, m, 3 × Trp β-H2 and AE 2-HH), 3.35–3.43 (2H,
m, AE 2-HH ), 3.46–3.50 (2H, m, Trp β-H2), 3.58–3.68 (6H, m,
2 × C-2 H2 and Gly α-H2), 3.69–3.75 (2H, m, 2 × Leu α-H),
3.82–3.88 (1H, m, Leu α-H), 3.90–3.95 (2H, m, THF 1Ј-H and
Leu α-H), 4.05–4.16 (5H, m, 2 × Val α-H, Gly α-H2 and Leu
α-H), 4.17–4.34 (13H, m, 4 × Ala α-H, Leu α-H, THF 5-H and
2-H and 6 × Val α-H), 4.41–4.61 (7H, m, 7 × Trp α-H), 6.88–
6.97 (6H, m, 6 × ar. CH), 6.99–7.05 (6H, m, 6 × ar. CH), 7.08
(6H, s, 6 × ar. CH), 7.13 (1H, s, ar. CH), 7.25–7.32 (7H, m, 7 ×
ar. CH), 7.36–7.47 (12H, 12 × ar. CH), 7.49–7.58 (7H, m, 7 × ar.
CH), 7.59–7.63 (12H, m, 10 × ar. CH and 2 × NH), 7.64–7.67
(1H, m, THF NH), 7.68–7.82 (3H, m, NH), 7.85 (1H, d, J 5.7,
Leu NH), 7.87–7.96 (7H, m, 7 × NH), 7.98 (1H, d, J 5.7, Leu
NH), 8.01–8.18 (8H, m, 7 × NH and Trp NH), 8.21–8.31 (6H,
m, Gly NH and 5 × Trp NH), 8.33 (1H, d, J 6.4, Trp NH), 10.71
Succ-(10,11[D-THF]-gA-TBDPS)2 7. 39.0 mg (17.7 µmol) of
methyl ester 34 were C-deprotected according to GP 1 (Rf =
0.20 in CHCl3–MeOH–HCO2H 100 : 10 : 1; HPLC: 9.8 min,
250 × 4 mm Jupiter C 5, 70 100% B in 25 min, A: H2O ϩ 0.1%
TFA; B: acetonitrile–isopropanol 2 : 1 ϩ 0.1% TFA; 0.7 ml
minϪ1). The crude carboxylic acid and 40.0 mg (22.5 µmol) of
amine 33a were collected and coupled according to GP 5 (1.0
m, 12 h). After aqueous work-up 64.0 mg of crude diamide 7
were isolated and purified directly by preparative HPLC (250
mm Rainin C 4, 60 100% B in 25 min, A: H2O ϩ 0.1% TFA;
O r g . B i o m o l . C h e m . , 2 0 0 3 , 1, 2 9 8 3 – 2 9 9 7
2996