G. Cabarrocas et al. / Tetrahedron: Asymmetry 11 (2000) 2483±2493
2491
arom.), 5.99 (s, 2H, OCH2O), 5.57 (s, br., 1H, NH), 5.10±4.90 (m, 1H, CH), 4.12 (dd, J=11.2 Hz,
J0=4.4 Hz, 1H, CH2O), 3.96 (dd, J=11.2 Hz, J0=4.2 Hz, 1H, CH2O), 2.50±1.90 (s, br., 1H, OH),
1.51 (s, 9H, C(CH3)3). 13C NMR (CDCl3), ꢂ =156.0 (s, CN), 151.8 (s, NCO), 147.8, 147.7,
143.8, 139.7 (4s, C arom.), 128.9, 127.6, 125.1 (3d, CH arom.), 123.9 (s, C arom.), 122.8, 109.1,
108.4, 106.3 (4d, CH arom.), 101.3 (t, OCH2O), 79.8 (s, C(CH3)3), 65.9 (t, CH2O), 50.7 (d, CH),
28.4 (q, C(CH3)3). MS (FAB+) m/e: 424 ([M+1]+, 71), 423 (M+, 10), 369 (52), 336 (26), 307 (100),
292 (69). Anal. calcd for C23H25N3O5 (423.46): C, 62.24%; H, 5.95%; N, 9.92. Found: C,
62.02%; H, 6.22%; N, 10.06%.
3.11. (2R)-2-[(1,1-Dimethylethoxy)carbonylamino]-2-[1-phenyl-5-(2-thienyl)-1H-3-pyrazolyl]-
ethan-1-ol 7d
According to the general procedure described in Section 3.7, reaction of 5d (286 mg, 0.67
20
mmol) aorded 215 mg (83%) of pure 7d as a yellowish oil. ꢀ ^46.9 (c 0.55, MeOH). IR (®lm,
D
ꢁ): 3500 br., 3423 m, 3103 w, 3071 w, 2972 m, 2926 m, 2871 m, 2857 m, 1706 s, 1597 m, 1501 s,
1455 m, 1369 m, 1323 w, 1275 m, 1249 m, 1166 s, 1055 m, 1024 m, 964 w, 929 m, 851 m, 794 w,
0
1
766 m, 697 m. H NMR (CDCl3), ꢂ=7.45±7.35 (m 5H, CH arom.), 7.32 (dd, J=5.2 Hz, J =1.2
Hz, 1H, CH arom.), 6.97 (dd, J=5.2 Hz, J0=3.6 Hz, 1H, CH arom.), 6.85 (dd, J=3.6 Hz, J0=1.2
Hz, 1H, CH arom.), 6.58 (s, 1H, CH arom.), 5.55 (s, br., 1H, NH), 5.10-4.90 (m, 1H, CH), 4.12
(dd, J=11.2 Hz, J0=4.2 Hz, 1H, CH2O), 2.40±1.80 (s, br., 1H, OH), 1.51 (s, 9H, C(CH3)3). 13C
NMR (CDCl3), ꢂ=156.0 (s, CN), 151.8 (s, NCO), 139.5, 137.9, 130.9 (3s, C arom.), 129.0,
128.4, 127.4, 127.3, 126.7, 126.1, 106.5 (7d, CH arom.), 79.8 (s, C(CH3)3), 65.8 (t, CH2O), 50.7 (d,
CH), 28.3 (q, C(CH3)3). MS (FAB+) m/e: 387 ([M+2]+, 25), 386 ([M+1]+, 97), 385 (M+, 4), 354
(22), 330 (69), 298 (25), 269 (100), 254 (59). Anal. calcd for C20H23N3O3S (385.48): C, 62.32%; H,
6.01%; N, 10.90; S, 8.32%. Found: C, 62.54%; H, 6.18%; N, 11.07%; S, 8.08%.
3.12. Synthesis of the Mosher's ester derivative 8
To a solution of the amino alcohol derivative 7c (25 mg, 0.058 mmol) in anhydrous CCl4 (0.29
mL), dry pyridine (0.17 mL) was added. After stirring for 5 min until homogenisation, (R)-(^)-
MPTA±Cl (15.2 mL, 0.082 mmol) was added. The reaction mixture was stirred at rt under N2 for
1 h. The mixture was diluted with CH2Cl2, and washed successively with sat. NaHCO3 and brine.
The organic layer dried over MgSO4, and ®ltered and the solvent eliminated under reduced
pressure to aord quantitatively 8 which was dried under H.V. and analysed without further
puri®cation. IR (KBr, ꢁ): 3362 br., 3064 w, 2956 m, 2923 m, 2853 m, 1751 s, 1712 s, 1599 m, 1500
s, 1487 s, 1454 m, 1371 m, 1333 w, 1238 s, 1167 s, 1123 m, 1078 w, 1035 w, 935 w, 864 w, 806 m,
1
765 m, 721 m, 697 m. H NMR (CDCl3), ꢂ=8.65 (s, br., 1H, NHCO), 7.60±7.25 (m, 10H, CH
arom.), 6.80±6.60 (m, 3H, CH arom.), 6.29 (s, 1H, CH arom.), 6.0 (s, 2H, OCH2O), 5.25 (s, br.,
1H, CH), 4.80±4.65 (m, 2H, CH2O), 3.52 (s, 3H, OCH3), 1.49 (s, 9H, C(CH3)3). 13C NMR
(CDCl3), ꢂ =166.3 (s, CO), 155.1 (s, CN), 149.9 (s, NCO), 149.7 (s, C arom.), 147.8, 147.6,
143.8, 139.8, 132.1 (1s, C arom.+CF3), 129.5, 128.9, 128.3, 127.6, 127.4, 125.1 (6s, CH arom.),
123.9 (s, C arom.), 122.8, 109.0, 108.4, 105.9 (4d, CH arom.), 101.3 (t, OCH2O), 79.9 (s,
C(CH3)3), 67.4 (t, CH2O), 55.4 (q, OCH3), 48.3 (d, CH), 28.32 (q, C(CH3)3). Anal. calcd for
C33H32F3N3O7 (639.62): C, 61.97%; H, 5.04%; N, 6.57. Found: C, 62.26%; H, 5.28.18%; N,
6.29%.