A. Kamal et al. / Tetrahedron: Asymmetry 14 (2003) 3861–3866
3865
54.00; H, 5.36; Cl, 14.49. Found: C, 53.96; H, 5.29; Cl,
14.39%.
8.17, 3.71), 7.2–7.4 (4H, m); EIMS (m/z): 172 (M+), 141
(M+−31). Anal. calcd for C8H9ClO2: C, 55.67; H, 5.26;
Cl, 20.54. Found: C, 55.48; H, 5.13; Cl, 20.14%.
4.4.12. (S)-2-Methylcarbonyloxy-2-(3-chloro-4-methoxy-
phenyl)ethyl acetate 5f. Yield: 40%; [h]2D5 +47.8 (c 4.30,
CHCl3); IR (neat): 1730 cm−1; 1H NMR (300 MHz,
CDCl3): l 2.1 (3H, s), 2.2 (3H, s), 3.9 (3H, s), 4.2 (1H,
dd, J=7.93, 11.70), 4.3 (1H, dd, J=4.15, 11.70), 5.9
(1H, dd, J=4.15, 7.93), 6.8 (1H, d, J=8.68), 7.2 (1H,
dd, J=8.68, 2.26), 7.4 (1H, d, J=2.26); EIMS (m/z):
226 (M+−60). Anal. calcd for C13H15ClO5: C, 54.46; H,
5.27; Cl, 12.37. Found: C, 54.39; H, 5.16; Cl, 12.26%.
4.5.4. (R)-1-(4-Bromophenyl)-1,2-ethanediol5b 6d. Yield:
92%; mp 103–104°C; 98% e.e.;13 tR(R) 23.32 min and
tR(S) 24.70 min; IR (neat): 3330 cm−1 (broad); 1H
NMR (200 MHz, CDCl3): l 2.0 (1H, broad s), 2.6 (1H,
broad s), 3.5 (1H, dd, J=8.30, 11.33), 3.7 (1H, dd,
J=11.33, 3.39), 4.8 (1H, dd, J=8.30, 3.39), 7.2 (2H, d,
J=7.93), 7.5 (2H, d, J=7.93); EIMS (m/z): 218 (M++
1), 216 (M+−1). Anal. calcd for C8H9BrO2: C, 44.27; H,
4.18; Br, 36.81. Found: C, 44.11; H, 4.04; Br, 36.63%.
4.4.13. (R)-2-(2,4-Dihlorophenyl)-2-hydroxyethyl acetate
4g. Yield: 45%; [h]2D5 −21.4 (c 1.40, CHCl3); IR (neat):
4.5.5. (R)-1-(4-Iodophenyl)-1,2-ethanediol5a 6e. Yield:
96%; mp 118–120°C; 97% e.e.;15 tR(R) 21.19 min and
tR(S) 22.80 min; IR (neat): 3350 cm−1 (broad); 1H
NMR (200 MHz, CDCl3): l 3.4 (2H, m), 4.4 (1H, t,
J=5.94), 4.6 (1H, m), 5.0 (1H, d, J=3.71), 7.2 (2H, d,
J=8.17), 7.6 (2H, d, J=8.17); EIMS (m/z): 264 (M+),
233 (M+−31). Anal. calcd for C8H9IO2: C, 36.39; H,
3.44; I, 48.06. Found: C, 36.26; H, 3.23; I, 47.96%.
1
3440, 1735 cm−1; H NMR (200 MHz, CDCl3): l 2.0
(3H, s), 3.9 (3H, s), 4.1 (1H, dd, J=8.30, 11.70), 4.2
(1H, dd, J=3.39, 11.70), 4.8 (1H, dd, J=3.39, 8.30),
6.8 (1H, d, J=8.68), 7.2 (1H, dd, J=8.68, 2.26), 7.4
(1H, d, J=2.26). Anal. calcd for C10H10Cl2O3: C, 48.22;
H, 4.05; Cl, 28.47. Found: C, 48.14; H, 3.97; Cl,
28.39%.
4.4.14. (S)-2-Methylcarbonyloxy-1-(2,4-dichlorophenyl)-
ethyl acetate 5g. Yield: 36%; [h]2D5 +22.7 (c 1.59,
CHCl3); IR (neat): 1730 cm−1; 1H NMR (200 MHz,
CDCl3): l 2.0 (3H, s), 2.1 (3H, s), 4.2–4.4 (2H, m), 6.3
(1H, dd, J=4.46, 6.69), 7.2 (1H, dd, J=8.91, 1.49), 7.3
(1H, d, J=8.91), 7.5 (1H, d, J=1.49). Anal. calcd for
C12H12Cl2O4: C, 49.51; H, 4.15; Cl, 24.36. Found: C,
49.38; H, 4.05; Cl, 24.16%.
4.5.6. (R)-1-(3-Chloro-4-methoxyphenyl)-1,2-ethanediol
6f. Yield: 96%; mp 94–95°C; 69% e.e.;13 tR(R) 34.23
min and tR(S) 38.40 min; IR (neat): 3340 cm−1 (broad);
1H NMR (200 MHz, CDCl3): l 2.0 (1H, broad s), 2.5
(1H, broad s), 3.6 (2H, m), 3.9 (3H, s), 4.7 (1H, dd,
J=3.71, 8.17), 6.8 (1H, d, J=8.91), 7.2 (1H, dd, J=
8.91, 2.23), 7.4 (1H, d, J=2.23); EIMS (m/z): 202 (M+),
171 (M+−31), 173 (M+−29). Anal. calcd for C9H11ClO3:
C, 53.35; H, 5.47; Cl, 17.50. Found: C, 53.27; H, 5.39;
Cl, 17.42%.
4.5. General procedure for ester hydrolysis reaction
To the solution of ester 4 and 5 (1 mmol) in 10 mL
methanol was added K2CO3 (1.5 mmol) and (2.5
mmol), respectively. The mixture was stirred for 4 h,
acidified with 1N HCl and extracted with ether, after
evaporation of the methanol.
4.5.7. (R)-1-(2,4-Dihloroyphenyl)-1,2-ethanediol 6g.
Yield: 90%; 40% e.e.;14 tR(R) 10.55 min and tR(S) 11.42
min; IR (neat): 3330 cm−1 (broad); 1H NMR (200 MHz,
CDCl3): l 3.4 (1H, dd, J=11.15, 8.17), 3.8 (1H, d,
J=11.15), 5.1 (1H, d, J=6.69), 7.2 (1H, dd, J=8.91,
1.49), 7.3 (1H, d, J=1.49), 7.5 (1H, d, J=8.17); EIMS
(m/z): 202 (M+), 171 (M+−31), 173 (M+−29). Anal.
calcd for C8H8Cl2O2: C, 46.41; H, 3.89; Cl, 34.24.
Found: C, 46.37; H, 3.82; Cl, 34.19%.
4.5.1. (R)-1-Phenyl-1,2-ethanediol5a 6a. Yield: 95%; mp
62–63°C; 70% e.e.;14 tR(R) 14.74 min and tR(S) 18.83
min; IR (neat): 3330 cm−1 (broad); 1H NMR (300 MHz,
CDCl3): l 2.8 (1H, broad s), 3.2 (1H, broad s), 3.6 (1H,
dd, J=11.33, 8.30), 3.7 (1H, dd, J=11.33, 3.39), 4.8
(1H, dd, J=3.39, 8.30), 7.3 (5H, m); EIMS (m/z): 138
(M+), 121 (M+−17), 107 (M+−31). Anal. calcd for
C8H10O2: C, 69.55; H, 7.29. Found: C, 69.35; H, 7.12%.
Acknowledgements
We are thankful to the Department of Science and
Technology, New Delhi for the financial support for
Grants-in-Aid project under SERC (No. SP/S1/G-47/
99). M.S. and A.A.S. are thankful to CSIR, New Delhi
for the award of research fellowship.
4.5.2. (R)-1-(4-Methylphenyl)-1,2-ethanediol5a 6b. Yield:
92%; mp 71–72°C [lit.12 76–76.5°C]; >99% e.e.;13 tR(R)
18.86 min and tR(S) 19.50 min; IR (neat): 3330 cm−1
(broad); 1H NMR (200 MHz, CDCl3): l 2.3 (3H, s), 3.6
(2H, m), 4.8 (1H, m), 7.0–7.4 (4H, m); EIMS (m/z): 152
(M+), 121 (M+−31). Anal. calcd for C9H12O2: C, 71.03;
H, 7.95. Found: C, 70.95; H, 7.86%.
References
4.5.3. (R)-1-(4-Chlorophenyl)-1,2-ethanediol5a 6c. Yield:
94%; mp 81–82°C [lit.12 76.5–78°C]; >99% e.e.;13 tR(R)
20.41 min and tR(S) 21.25 min; IR (neat): 3340 cm−1
(broad); 1H NMR (200 MHz, CDCl3): l 2.2 (1H, broad
s), 2.4–2.6 (1H, broad s), 3.5–3.6 (1H, dd, J=8.17,
11.15), 3.7 (1H, dd, J=3.71, 11.15), 4.8 (1H, dd, J=
1. (a) Rao, A. V. R.; Bose, D. S.; Gurjar, M. K.; Ravin-
dranathan, T. Tetrahedron 1989, 45, 7031; (b) Seyden-
Penn, J. Chiral Auxiliaries and Ligands in Asymmetric
Synthesis; John Wiley: New York, 1995; (c) Wright, A.
E.; Scha¨fer, M.; Midland, S.; Munnecke, D. E.; Sims, J.
J. Tetrahedron Lett. 1989, 30, 5699.