2204
J. NOWICKA-SCHEIBE
þ
=
(Ar), 176.83 (C O); GC-MS (EI, 70 eV): m=z ¼ 307 (37, M ), 281 (1), 262 (9), 236
(3), 218 (2), 194 (16), 169 (13), 143 (38), 109 (100), 91 (35), 67 (28), 50 (26), 41
(33). Found: C, 62.60; H, 5.41; Cl, 11.06, N, 4,12. C16H18ClNO3 requires C,
62.44; H, 5.89; Cl, 11.52; N, 4.55%.
Compound 4e, (1RS,3SR)-3-(6-chloro-5-nitro-benzooxazol-2-yl)-1,2,
2-trimethyl-cyclopentanecarboxylic acid. Yellow solid, mp 216–218 ꢂC from
n-hexane–ethyl acetate. IR (KBr pellet): n ¼ 3420 (br), 2972 (vbr), 1690 (vs), 1608
(w), 1554 (vs), 1536 (vs), 1448 (vs), 1408 (w), 1344 (m), 1260 (m), 1146 (m), 1118
1
(m), 1004 (m), 960 (m), 882 (m), 836 (m) cmꢀ1; H NMR (400.1 MHz, DMSO-d6)
d ¼ 0.66 (3 H, s, 1-CH3), 1.28 (3 H, s, 2-CH3), 1.29 (3 H, s, 2-CH3), 1.56 (1 H, ddd,
J ¼ 13.6, 9.6, 3.9 Hz, CHH-5), 2.07–2.20 (1 H, m, CHH-4), 2.33–2.46 (1 H, m,
CHH-4), 2.58 (1 H, ddd, J ¼ 13.6, 12.1, 7.1 Hz, CHH-5), 3.62 (1 H, t, J ¼ 9.5 Hz,
CH-3), 8.21 (1 H, s, Ar), 8.64 (1 H, s, Ar), 12.34 (1 H, v br s, COOH); 13C NMR
(100.6 MHz, DMSO-d6): d ¼ 21.05 (1-CH3), 21.78, 22.44 (2 ꢁ 2-CH3), 23.34 (CH2-
4), 32.26 (CH2-5), 47.51 (C-2, CH-3), 55.64 (C-1), 109.13, 121.24, 121.68, 144.36,
ꢀ
=
144.56, 148.23, 173.35 (Ar), 176.71 (C O); ESI-MS m=z ¼ 353 [M-H] . Found: C,
54.76; H, 4.30; Cl, 9.89; N, 7.26%. C16H17ClN2O5 requires C, 54.48; H, 4.86; Cl,
10.05; N, 7.94%.
Compound 4f, (1RS,3SR)-1,2,2-trimethyl-3-naphtho[2,3-d]oxazol-2-yl-
cyclopentanecarboxylic acid. Yellow solid, mp 223–225 ꢂC from n-hexane–ethyl
acetate. IR (KBr pellet): n ¼ 3412 (vbr), 3040 (w), 2976 (vbr), 1692 (vs), 1650 (w),
1626 (m), 1568 (s), 1506 (m) 1444 (m), 1406 (s), 1310 (m), 1288 (s), 1248 (s), 1178
1
(m), 1118 (m), 956 (m), 868 (s), 742 (s) cmꢀ1; H NMR (400.1 MHz, DMSO-d6)
d ¼ 0.70 (3 H, s, 1-CH3), 1.26 (3 H, s, 2-CH3), 1.30 (3 H, s, 2-CH3), 1.58 (1 H, ddd,
J ¼ 13.2, 9.6, 3.8 Hz, CHH-5), 2.14 (1 H, dtd, J ¼ 13.4, 9.5, 6.9 Hz, CHH-4),
2.43–2.54 (1 H, m, CHH-4), 2.61 (1 H, ddd, J ¼ 13.2, 12.1, 6.8 Hz, CHH-5), 3.59
(1 H, t, J ¼ 9.4 Hz, CH-3), 7.48–7.56 (2 H, m, Ar), 8.02-8.10 (2 H, m, Ar), 8.18
(1 H, s, Ar), 8.26 (1 H, s, Ar), 12.30 (1 H, v br s, COOH); 13C NMR (100.6 MHz,
DMSO-d6) d ¼ 21.14 (1-CH3), 21.80, 22.61 (2 ꢁ 2-CH3), 23.31 (CH2-4), 32.32
(CH2-5), 47.21 (C-2), 47.49 (CH-3), 55.62 (C-1), 106.32, 116.61, 124.79, 125.51,
=
128.00, 128.42, 130.93, 131.07, 140.85, 149.29, 170.22 (Ar), 176.84 (C O); GC-MS
(EI, 70 eV): m=z ¼ 323 (0), 295 (M-CO), 262 (28), 244 (23), 204 (17), 183 (14), 159
(7), 141 (5), 115 (17), 88 (4), 67 (3), 43 (17);
Found: C, 74.61; H, 6.40; N, 4.02%. C20H21NO3 requires C, 74.28; H, 6.55; N,
4.33%.
Compound 4g, (1RS,3SR)-(1,2,2-trimethyl-3-(5-phenyl-benzooxazol-
2-yl)-cyclopentanecarboxylic acid. White solid, mp 217–219 ꢂC from n-hexane:
ethyl acetate. IR (KBr pellet): n ¼ 3444 (br), 2968 (vbr), 2336 (w), 1720 (vs), 1560
(s), 1470 (s). 1422 (m), 1380 (m), 1262 (m), 1210 (m), 1156 (m), 1112 (m), 956 (m),
820 (m), 760 (s), 696 (s) cmꢀ1
;
1H NMR (400.1 MHz, CDCl3: DMSO-d6 ¼ 3:1)
(¼0.78 (3 H, s, 1-CH3), 1.34 (3 H, s, 2-CH3), 1.36 (3 H, s, 2-CH3), 1.63 (1 H, ddd,
J ¼ 13.2, 9.5, 3.5 Hz, CHH-5), 2.08–2.21 (1 H, m, CHH-4), 2.47–2.63 (1 H, m,
CHH-4), 2.71 (1 H,td, J ¼ 13.2, 6.6 Hz, CHH-5), 3.48 (1 H, t, J ¼ 9.5 Hz, CH-3),
7.31–7.38 (1 H, m, C6H5), 7.45 (2 H, t, J ¼ 7.6 Hz, C6H5), 7.54 (1 H, dt, J ¼ca. 8.4,
1.7 Hz, C6H3), 7.57–7.63 (3 H, m, C6H3, C6H5), 7.85 (1 H, br s, C6H3); 13C NMR