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4.67 (d, H C(a)); 5.03 (d, NH); 7.07 (d, H C(6)); 7.36 (m, H C(5'), H C(4)); 7.48 (m, H C(6'), H C(7));
7.51 (d, H C(7')); 8.09 (d, H C(2')); 8.49 (m, H C(4')); 8.63 (d, H N(1')). 13C-NMR: 28.53 (Me3C); 38.62
(C(b)); 52.50 (MeO); 54.98 (C(a)); 80.82 (Me3); 105.75 (C(3')); 110.10 (C(7)); 111.79 (C(6')); 119.96 (C(7'));
121.82 (C(4')); 122.23 (C(5')); 123.82 (C(4)); 125.26 (C(6)); 125.33 (C(7'a)); 127.64 (C(2')); 132.33 (C(3'a));
136.51 (C(5)); 143.21 (C(3a)); 149.41 (C(7a)); 151.83 (C(2)); 162.03 (HNCOO); 172.53 (C(a)COO). Anal.
calc. for (C24H25N3O5): C 66.19, N 9.65, H 5.79; found: C 66.14, N 9.58, H 5.73. 1H,13C-HSQC: 8 cross-peaks
within 7 ± 9 ppm (arom. H) and 100 ± 160 ppm (arom. C). FAB-MS: 436 ([M 1] ).
e) Data of 3-[4-Bromo-2-(1H-indol-3-yl)benzoxazol-5-yl]-N-[(tert-butoxy)carbonyl]-l-alanine Methyl
Ester (5): White solid. M.p. 203 ± 2048. [a]2D0 2.35 (c 0.01m, MeOH). FT-IR: 3416.0s, 3340.3s, 1732.7s,
1687.4s, 1630.1m, 1603.6m, 1578.8s, 1522.1m, 1057.0m. 1H-NMR: 1.44 (s,tBu); 3.23 (m, CH2(b)); 3.77 (s, MeO);
4.65 (d, H C(a)); 5.06 (d, NH); 7.22 (d, H C(6)); 7.37 (m, H C(6'), H C(5')); 7.43 (d, H C(7)); 7.49
(m, H C(7')); 8.14 (d, H C(2')); 8.48 (m, H C(4')); 8.71 (d, H N(1')). 13C-NMR: 28.53 (Me3C); 38.26
(C(b)); 52.65 (MeO); 54.86 (C(a)); 80.43 (Me3C); 101.99 (C(3')); 105.07 (C(4)); 111.86 (C(7')); 118.95 (C(7));
121.78 (C(4')); 122.45 (C(6')); 123.97 (C(5')); 125.17 (C(7'a)); 128.20 (C(2')); 128.29 (C(6)); 134.01 (C(3'a));
1
136.45 (C(5)); 143.64 (C(3a)); 147.55 (C(7a)); 155.43 (C(2)); 161.84 (HNCOO); 172.25 (C(a)COO). H,13C-
HSQC: 7 cross-peaks within 7 ± 9 ppm (arom. H) and 100 ± 160 ppm (arom. C). 1H,1H TOCSY: 3 spin systems,
i.e. H C(4')/H C(5')/H C(6')/H C(7') (indole moiety) H N(1')/H C(2') (indole moiety), and H C(6)/
H
C(7) (benzoxazole moiety). FAB-MS: 514 and 516 ([M 1] ).
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