6018
A. S. Kende et al. / Tetrahedron Letters 42 (2001) 6015–6018
(ABX, JAB=13.5 Hz, JAX=8.7 Hz, JBX=5.2 Hz, 2H),
7.16–7.33 (m, 5H) ppm; 13C NMR (CD3OD, 100 MHz):
l 26.3 (t), 27.4 (q), 28.5 (t), 28.8 (t), 31.8 (t), 41.1 (t), 44.7
(d), 50.8 (t), 52.0 (d), 78.3 (s), 125.7 (d), 127.8 (d), 129.0
(d), 138.7 (s), 156.6 (s), 178.1 (s) ppm. HRMS (M+H)
calcd: 391.2345; found: 391.2364.
3.29 (t, J=6.7 Hz, 2H), 3.60 (m, 1H), 5.71 (br, 1H),
7.18–7.36 (m, 5H) ppm; 13C NMR (CDCl3, 100 MHz): l
26.1 (t), 26.3 (t), 28.4 (t), 29.1 (t), 40.7 (d), 43.5 (t), 51.5
(t), 54.6 (d), 127.0 (d), 128.9 (d), 129.1 (d), 136.6 (s), 173.9
(s) ppm. Anal. calcd for C15H20N4O: C, 66.15; H, 7.40;
N, 20.57. Found: C, 66.00; H, 7.54; N, 20.42%. Com-
pound 8b (more polar): a colorless oil, [h]D=+86.7 (c=
17. Golding, B. T.; Mitchinson, A.; Clegg, W.; Elsegood, M.
R. J.; Griffin, R. J. J. Chem. Soc., Perkin Trans. 1 1999,
349.
1
0.81, CHCl3); H NMR (CDCl3, 400 MHz): l 1.50–1.75
18. Compound 11a: [h]D=−5.6 (c=0.45, MeOH), mp 75–
77°C, 1H NMR (CD3OD, 400 MHz): l 1.38 (s, 9H),
1.43–1.72 (m, 8H), 2.38 (m, 1H), 2.71 (d, J=7.0 Hz, 2H),
3.24 (t, J=6.3 Hz, 2H), 3.75 (m, 1H), 7.16–7.28 (m, 5H)
ppm; 13C NMR (CD3OD, 100 MHz): l 27.3 (q), 28.4 (t),
29.1 (t), 31.9 (t), 40.6 (t), 41.4 (t), 44.5 (d), 51.6 (d), 78.3
(s), 125.7 (d), 127.8 (d), 129.0 (d), 138.7 (s), 156.7 (s),
159.5 (s), 178.3 (s) ppm. HRMS (M+Na): calcd 474.2329;
found: 474.2341. Compound 11b: [h]D=−1.3 (c=0.38,
(m, 5H), 1.82–1.88 (m, 3H), 2.31 (m, 1H), 2.68, 2.84
(ABX, JAB=13.4 Hz, JAX=8.4 Hz, JBX=5.7 Hz, 2H),
3.32 (m, 2H), 3.62 (m, 1H), 5.86 (br, 1H), 7.17–7.35 (m,
5H) ppm; 13C NMR (CDCl3, 100 MHz): l 23.7 (t), 25.3
(t), 26.8 (t), 29.1 (t), 40.0 (d), 43.1 (t), 51.4 (t), 53.8 (d),
126.9 (d), 128.8 (d), 129.2 (d), 136.9 (s), 174.5 (s) ppm.
Anal. calcd for C15H20N4O: C, 66.15; H, 7.40; N, 20.57.
Found: C, 66.05; H, 7.61; N, 20.19%.
16. Compound 10a: a colorless oil, [h]D=−3.4 (c=1.73,
CHCl3); 1H NMR (CD3OD, 400 MHz): l 1.38 (s, 9H),
1.48–1.69 (m, 8H), 2.37 (m, 1H), 2.71 (d, J=7.0 Hz, 2H),
3.29 (t, J=6.2 Hz, 2H), 3.74 (m, 1H), 7.16–7.33 (m, 5H)
ppm; 13C NMR (CD3OD, 100 MHz): l 26.4 (t), 27.3 (q),
28.4 (t), 29.2 (t), 31.8 (t), 41.4 (t), 44.4 (d), 50.8 (t), 51.5
(d), 78.3 (s), 125.7 (d), 127.8 (d), 129.0 (d), 138.7 (s),
156.7 (s), 178.1 (s) ppm. HRMS (M+H): calcd 391.2345;
found: 391.2354. Compound 10b: a colorless oil, [h]D=
1
MeOH), mp 80–82°C, H NMR (CD3OD, 400 MHz): l
1.38 (s, 9H), 1.54–1.61 (m, 8H), 2.33 (m, 1H), 2.72 (d,
J=7.6 Hz, 2H), 3.23 (t, J=6.4 Hz, 2H), 3.68 (m, 1H),
7.16–7.28 (m, 5H) ppm; 13C NMR (CD3OD, 100 MHz):
l 27.4 (q), 28.6 (t), 28.7 (t), 31.9 (t), 40.6 (t), 41.1 (t), 44.8
(d), 52.0 (d), 78.3 (s), 125.7 (d), 127.8 (d), 129.0 (d), 138.7
(s), 156.7 (s), 159.5 (s), 178.3 (s) ppm. HRMS (M+Na):
calcd 474.2329; found: 474.2338.
1
19. For an alternative strategy toward a Phe-Arg hydroxy-
ethylene isostere, see: Brewer, M.; Rich, D. H. Org. Lett.
2001, 3, 945.
−0.5 (c=1.48, CHCl3), H NMR (CD3OD, 400 MHz): l
1.39 (s, 9H), 1.51–1.63 (m, 8H), 2.30 (m, 1H), 2.72 (d,
J=7.0 Hz, 2H), 3.28 (t, J=6.1 Hz, 2H), 3.69 (m, 1H),
.