8740
K. Sarma et al. / Tetrahedron 63 (2007) 8735–8741
showed it to be 80% ee [hexane/2-propanol 9:1; flow rate
0.8 cm3 minꢁ1]; nmax (neat/cmꢁ1) 3054, 2992, 2920, 1602,
1496, 1478, 1417, 1381, 1199, 1090, 1015, 987, 879, 831,
769; dH (300 MHz, CDCl3) 2.68–2.69 (1H, dd, J 2.6 and
5.4, HCOCHH), 3.08 (1H, dd, J 4.0 and 5.4, HCOCHH),
3.77 (1H, dd, J 2.6 and 4.0, PhCHOCH2), 7.13–7.26 (4H,
m, 4ꢂCH, arom.); dC (300 MHz, CDCl3) 51.2 (CH2), 51.8
(CH), 126.7, 126.6, 133.9 and 136.1 (6ꢂC–Ph). MS m/z
(rel intensity %): 156, 154 (M+1, 2, 8), 155, 153 (M+, 3,
7), 138 (3), 125 (40), 119 (39), 91 (29), 89 (100), 63 (34),
50 (17).
4.4.11. (R)-(D)-a-Methylstyrene oxide (11).27,31 Yield
55%, oil. (Found: C, 80.59; H, 7.45. C9H10O requires: C,
80.60; H, 7.46%.) Rf (40% CH2Cl2/hexane) 0.51; [a]D25
+6.1 (c 2.85, CHCl3) {lit.27 [a]D25 ꢁ7.8 (c 3.84, CHCl3),
99% ee, S}. The enantiomeric excess was determined with
a Hewlett–Packard 5890 gas chromatograph equipped with
an FID detector, using a Chiraldex G-TA capillary column
and showed it to be 78% ee; nmax (neat/cmꢁ1) 1496, 1476,
1452, 1390; dH (300 MHz, CDCl3) 1.62 (3H, s, CH3), 2.65
(1H, d, J 5.5, OCHH), 2.84 (1H, d, J 5.5, OCHH), 7.21–
7.40 (5H, m, 5ꢂCH, arom.); dC (300 MHz, CDCl3) 21.5
(CH3), 56.6 (CH2), 56.8 (PhCO), 125.2, 127.4, 128.2 and
141.1 (6ꢂC–Ph).
4.4.12. (R)-(L)-4-Methylstyrene oxide (12).27,30 Yield
60%, oil. (Found: C, 80.59; H, 7.45. C9H10O requires: C,
80.60; H, 7.46%.) Rf (40% CH2Cl2/hexane) 0.45; [a]D25
ꢁ13.63 (c 1.77, CHCl3) {lit.27 [a]D25 +19.5 (c 1.97,
CHCl3), 99% ee, S}. The enantiomeric excess was deter-
mined with a Hewlett–Packard 5890 gas chromatograph
equipped with an FID detector, using a CP-cyclodextrin-b-
2,3,6-M-19 capillary column and showed it to be 70% ee;
nmax (neat/cmꢁ1) 1495, 1475, 1450, 1395; dH (300 MHz,
CDCl3) 2.45 (3H, s), 2.91 (1H, dd, J 2.4 and 5.5, HCOCHH),
3.24 (1H, dd, J 4.2 and 5.5, HCOCHH), 3.84 (1H, dd, J 2.4
and 4.2, PhCHOCH2), 7.31–7.40 (4H, m, 4ꢂCH, arom.); dC
(300 MHz, CDCl3) 20.7 (CH3), 50.9 (CH2), 52.2 (CH),
125.4, 128.9, 134.4 and 137.8 (6ꢂC–Ph).
4.4.8. (R)-(D)-(2-Bromophenyl)-oxirane (8).25 Yield 69%,
oil. (Found: C, 54.05; H, 3.16. C8H7OBr requires: C, 54.05;
H, 3.15%.) Rf (30% EtOAc/hexane) 0.54; [a]1D8 +51.52 (c
1.10, CHCl3), 75% ee {lit.25 [a]D18 +68.7 (c 1.12, CHCl3),
R}. The enantiomeric excess was measured by capillary
GC analysis using Chiraldex. G-PN column (Astec); nmax
(neat/cmꢁ1) 3055, 2991, 2916, 1569, 1472, 1440, 1381,
1248, 1045, 1026, 879, 753; dH (300 MHz, CD3COCD3)
2.65 (1H, dd, J 2.6 and 5.9, HCOCHH), 3.17 (1H, dd,
J 4.1 and 5.9, HCOCHH), 4.13 (1H, dd, J 2.6 and
4.1, PhCHOCH2), 7.08–7.38 (3H, m, 3ꢂCH, arom.), 7.54
(1H, dd, J 1.1 and 8.0, 1ꢂCH, arom.); dC (300 MHz,
CDCl3) 50.5 (CH2), 51.7 (CH), 123.5, 127.6, 128.6, 129.4,
132.8, 136.8 (6ꢂC–Ph); MS m/z (rel intensity %): 200,
198 (M+, 17, 18), 199, 197 (M+ꢁ1, 16, 15), 185 (1), 171
(9), 169 (10), 141 (1), 120 (7), 119 (84), 91 (63), 90 (41),
89 (100).
Acknowledgements
4.4.9. (R)-(D)-(3-Bromophenyl)-oxirane (9).25 Yield 63%,
oil. (Found: C, 54.04; H, 3.13. C8H7OBr requires: C, 54.05;
H, 3.15%.) Rf (30% EtOAc/hexane) 0.51; [a]2D7 +8.45 (c
1.10, CHCl3), 73% ee {lit.25 [a]D27 +4.0 (c 1.12, CHCl3),
35% ee, R}. The enantiomeric excess was determined by
HPLC analysis using a Chiralpak AS column (eluent at
V¼0.8 mL minꢁ1; hexane/2-propanol 9:1). nmax (neat/
cmꢁ1) 3057, 2992, 1600, 1571, 1478, 1431, 1385, 1369,
1201, 1070, 997, 877, 786, 691; dH (300 MHz, CDCl3)
2.77 (1H, dd, J 2.5 and 5.4, HCOCHH), 3.15 (1H, dd, J
4.1 and 5.4, HCOCHH), 3.81 (1H, dd, J 2.5 and 4.1,
PhCHOCH2), 7.10–7.50 (4H, m, 4ꢂCH, arom.); dC
(300 MHz, CDCl3) 51.0 (CH2), 52.2 (CH), 122.5, 127.6,
130.0, 131.0, 131.7, 136.7 (6ꢂC–Ph); MS m/z (rel intensity
%): 200, 198 (M+, 23, 23), 199, 197 (M+ꢁ1, 32, 32), 69 (27),
141 (16), 119 (67), 91 (60), 89 (100).
We gratefully acknowledge the DST, New Delhi for the re-
search grant and Dr. P. G. Rao, Director, Regional Research
Laboratory, Jorhat, for providing the facility to carry out the
work.
References and notes
1. Smith, G. J. Synthesis 1984, 8, 629.
2. Besse, P.; Veschambre, H. Tetrahedron 1994, 50, 8885.
3. Xia, Q.-H.; Ge, H.-Q.; Ye, C.-P.; Liu, Z.-M.; Su, K.-X. Chem.
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5. Fringuelli, G.; Pizzo, S. Synth. Commun. 1989, 19, 1939.
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4.4.10. (R)-(L)-(4-Bromophenyl)-oxirane (10).30 Yield
71%, oil. (Found: C, 54.05; H, 3.14. C8H7OBr requires: C,
54.05; H, 3.15%.) Rf (30% EtOAc/hexane) 0.49; [a]D23
ꢁ10.9 (c 1.2, CHCl3) {lit.30 [a]D20 +13.6 (c 1.46, CHCl3),
98% ee, S}. The enantiomeric excess was determined by
HPLC analysis using a Chiralcel OJ column and showed it
to be 78% ee (eluent at V¼0.8 mLminꢁ1; hexane/2-propanol
100:1); nmax (neat/cmꢁ1) 3051, 2991, 2919, 1595, 1490,
1415, 1378, 1101, 1073, 1011, 987, 878, 828; dH
(300 MHz, CDCl3) 2.73 (1H, dd, J 2.7 and 5.4, HCOCHH),
3.13 (1H, dd, J 3.6 and 5.4, HCOCHH), 3.81 (1H, dd, J 2.7
and 3.6, PhCHOCH2), 7.05–7.18 (2H, m, 2ꢂCH, arom.),
7.40–7.48 (2H, m, 2ꢂCH, arom.); dC (300 MHz, CDCl3)
50.6 (CH2), 52.0 (CH), 121.1, 128.6, 131.6, 135.8 (6ꢂC–
Ph); MS: m/z (rel intensity %): 200, 198 (M+, 4), 199, 197
(Mꢁ1, 3), 169 (14), 119 (41), 89 (100), 63 (36).
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