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O. K. Choi, B. T. Cho / Tetrahedron: Asymmetry 12 (2001) 903–907
THF. To this was added slowly a THF solution of 9 (2
mL, 2 mmol) over a period of 1 h at 25°C using a
syringe pump. After the addition, the reaction mixture
was stirred for 10 min, quenched cautiously with
methanol (0.5 mL), and stirred for an additional 30
min. The solvent was evaporated under reduced pres-
sure to give the crude products 10 and 11 in quantita-
tive yield. These were further purified by flash column
chromatography on silica gel (230–400 mesh) using
hexane/ethyl acetate (1/2) as the eluent to give insepar-
able mixture of 10 and 11; 99% yield; Rf 0.47; mp
128.03, 128.72, 129.86, 134.27, 138.30, 141.50, 144.91;
13: 1H NMR (400 MHz, CDCl3): l 0.01 (s, 6H), 0.75 (s,
9H), 2.33 (s, 3H), 2.79 (dd, 1H, dd, 1H, J=7.10 and
12.15 Hz), 3.15 (dd, 1H, J=7.26 and 16.10 Hz), 4.75
(dt, 1H, J=5.63 and 7.10 Hz), 5.10 (d, 1H, J=5.59
Hz), 7.02 (m, 1H), 7.09–7.25 (m, 5H), 7.72 (d, 2H,
J=9.33 Hz); 13C NMR (125 MHz, CDCl3): l −4.61,
−4.54, −2.95, 17.94, 18.32, 21.63, 25.65, 25.69, 35.69,
75.19, 79.40, 124.03, 124.80, 127.27, 127.87, 128.63,
129.74, 133.63, 137.23, 140.88, 144.60; comparison of
1
integration of each chemical shift of H NMR spectra
1
68–71°C; IR (KBr, cm−1): 3503, 1364, 1188, 926; H
at C-(1) and C-(2) in 12 and 13 showed the formation
of 12 and 13 in a ratio of 59:41; HRMS calcd for
(C22H30O4SSi+H)+: 419.1707; found: 419.1712.
NMR (400 MHz, CDCl3): l 2.39 (br s, 1H), 2.46 (s,
3H), 3.02 (m, 1H), 3.21 (m, 1H), 4.86 (dt, 0.4H, J=5.51
and 7.72 Hz), 5.11 (m, 1.2H), 5.36 (t, 0.4H, J=4.89
Hz), 7.15 (m, 1H), 7.26–7.28 (m, 2H), 7.36–7.41 (m,
3H), 7.84 (d, 2H, J=8.29 Hz); 13C NMR (100 MHz): l
22.33, 36.32, 36.60, 75.59, 80.14, 83.18, 89.39, 125.07,
125.27, 125.70, 128.32, 128.48, 128.65, 128.81, 129.68,
129.94, 130.69, 134.09, 137.63, 138.92, 140.66, 141.32,
145.89. Anal. calcd for C16H16O4S: C, 63.14; H, 5.30; S,
10.54. Found: C, 62.79; H, 5.65; S, 10.45%.
4.6. Preparation of (1S,2R)-indene oxide 1 and
(1S,2R)-10
To a solution of the mixture of 12 and 13 (1.674 g, 4
mmol) in THF (3 mL) was added TBAF (1 M in THF,
4.8 mL, 4.8 mmol) and the mixture was stirred at room
temperature for 1 h. THF was evaporated in vacuo.
Flash column chromatography of the crude products
obtained after column chromatography purification
over silica gel (Merck 60, 230–400 mesh) using hexane/
ethyl acetate (2/1) as the eluent give (1S,2R)-1 in 37%
yield and (1S,2R)-10 in 57% yield. (1S,2R)-1:4 Rf 0.70;
oil; IR (neat, cm−1) 3039, 2914, 1474, 1418, 1371, 1230,
982; 1H NMR (400 MHz, CDCl3): l 2.96 (dd, 1H,
J=2.94 and 18.01 Hz), 3.20 (d, 1H, J=17.89 Hz), 4.12
(t, 1H, J=2.94 Hz), 4.25 (m, 1H), 7.16–7.27 (m, 3H),
7.49 (d, 1H, J=7.34 Hz); 13C NMR (125 MHz,
CDCl3): l 34.57, 57.63, 59.07, 125.13, 126.03, 126.18,
128.50, 140.82, 143.50; [h]2D0 +55.3 (c 1.0, CHCl3) [lit.4
−55.0 (CHCl3), >98% ee for (1R,2S)-1]; an HPLC
analysis using a Chiralcel OB chiral column (Daicel)
showed it to have 99.2% e.e. [eluent: hexane/EtOAc=
99.5/0.5; flow rate: 1.0 mL/min; tR (1S,2R) 25.38 min
and tR (1R,2S) 36.25 min]; (1S,2R)-10: Rf 0.47; mp
Reduction of 3 using the same method as described
above provided cis-2-bromo-2-indanol 8 in 99% yield;
Rf 0.27 (hexane/EtOAc=4/1); mp 112–113°C (lit.5b
107–109°C); IR (KBr, cm−1): 3336, 1474, 1422, 1301,
1
1273, 1112; H NMR (400 MHz, CDCl3): l 2.45 (d,
1H, J=5.98 Hz), 3.41 (m, 2H), 4.92 (m, 1H), 4.98 (m,
1H), 7.25–7.32 (m, 3H), 7.45 (m, 1H); 40.19, 60.76,
76.26, 124.60, 124.98, 127.49, 128.74, 139.18, 141.65.
13C NMR (125 MHz, CDCl3): l 40.19, 60.76, 76.26,
124.60. 124.98, 127.49, 128.74, 139.18, 141.65. An
HPLC analysis using a Chiralcel OB chiral column
(Daicel) showed it to be 2% e.e. [eluent: hexane/
EtOAc=99/1; flow rate: 1.0 mL/min; tR (1S,2R) 23.71
1
min and tR (1R,2S) 30.44 min]. H NMR spectra of 8
obtained were in agreement with reported data.5b
1
4.5. Preparation of cis- and trans-2-p-toluenesulfonyl-
oxy-1-(tert-butyldimethylsilyl-oxy)indanes 12 and 13
70–71°C; IR (KBr, cm−1): 3503, 1364, 1188, 926; H
NMR (400 MHz, CDCl3): l 2.40 (br s, 1H), 2.46 (s,
3H), 3.05 (dd, 1H, J=5.45 and 16.49 Hz), 3.18 (dd, 1H,
J=3.95 and 16.49 Hz), 5.12 (m, 2H), 7.19 (m, 1H),
7.26–7.28 (m, 2H), 7.36–7.41 (m, 3H), 7.84 (d, 2H,
J=8.29 Hz); 13C NMR (100 MHz): l 22.10, 36.37,
75.33, 125.28, 125.42, 128.04, 128.36, 129.65, 130.40,
133.83, 141.04, 145.59; [h]2D0 −17.7 (c 1.0, CHCl3); it was
shown to have 87% e.e. by HPLC analysis of (1S,2S)-2
obtained from conversion of (1S,2R)-10 using a Chiral-
cel OB chiral column (Daicel).
To a cooled solution of the mixture of 10 and 11 (1.522
g, 5 mmol) and imidazole (0.681 g, 10 mmol) dissolved
in DMF (20 mL) was added TBS-Cl (1.13 g, 7.5 mmol)
dropwise over 10 min in an ice bath. After the reaction
mixture was stirred for 3 h at room temperature, water
(20 mL) was added and the mixture was stirred.
Product was extracted with dichloromethane. Organic
phase was dried over anhydrous MgSO4, filtered and
evaporated in vacuo. An inseparable mixture of 12 and
13 was obtained in 99% yield by flash column chro-
matography of crude products on silica gel (Merck 60,
230–400 mesh) using hexane/ethyl acetate (2/1) as the
eluent; 99% yield; Rf 0.65; oil; IR (neat, cm−1): 2933,
4.7. Preparation of (1S,2S)-2-bromo-1-indanol 2
A suspension of (1S,2R)-10 (0.307 g, 1.0 mmol) and
tetra-n-butylammonium bromide (0.387 g, 1.2 mmol) in
iso-propyl ether (5 mL) was heated to reflux under
nitrogen for 4 h. The reaction mixture was cooled to
room temperature and water (8 mL) was added and the
mixture stirred. The organic layer was separated and
then the aqueous layer was extracted with ether. Then
the combined organic layer was dried over anhydrous
MgSO4, filtered and concentrated. The crude (1S,2S)-2
obtained was further purified by flash column chro-
1
1599, 1471, 1369, 1255, 1182, 1092; 12: H NMR (400
MHz, CDCl3): l 0.01 (s, 6H), 0.76 (s, 9H), 2.31 (s, 3H),
2.83 (dd, 1H, dd, 1H, J=5.90 and 15.70 Hz), 3.03 (dd,
1H, J=5.44 and 15.88 Hz), 4.86 (q, 1H, J=5.44 Hz),
4.95 (d, 1H, J=4.75 Hz), 7.02 (m, 1H), 7.07–7.20 (m,
5H), 7.68 (d, 2H, J=8.28 Hz); 13C NMR (125 MHz,
CDCl3): l −4.77, −4.54, −3.58, 17.97, 18.32, 21.63,
25.67, 25.79, 35.69, 75.19, 81.70, 124.48, 124.98, 127.47,