3950
C. E. Costa et al. / Tetrahedron: Asymmetry 15 (2004) 3945–3954
chromatography eluting with hexane–ethyl acetate
(85:15).
4.2.2.2. (RS)-1-(Phenylseleno)-2-octanol, (RS)-1c.
Oil; yield: 0.473g (83%); CAS NR: 52954-45-7; NMR
1H (500MHz): 0.87 (t, 3H, J = 7.1Hz), 1.25–1.31 (m,
8H), 1.51–1.54 (m, 2H), 2.14 (br s, 1 H), 2.87 (dd, 1H,
J = 8.6, 12.7Hz), 3.14 (dd, 1H, J = 3.5, 12.7Hz), 3.63–
3.68 (m, 1H), 7.24–7.27 (m, 3H), 7.51–7.54 (m, 2H);
NMR 13C (125MHz): d 14.0, 22.5, 29.23, 31.7, 36.6,
37.2, 69.8, 127.2, 129.2, 133.0; NMR 77Se (95MHz): d
237.0; IR 691, 736, 1024, 1070, 1478, 1578, 1712, 1799,
1873, 1946, 2855, 2928, 3056, 3070, 3399cmÀ1; MS m/z
(rel int): 286 (68), 172 (96), 158 (71), 129 (23), 91 (78),
77 (70), 69 (96), 55 (100), 51 (48), 45 (42); Anal. Calcd
for C14H22OSe: C, 58.94; H, 7.77. Found: C, 59.31; H,
7.97.
4.2.1.1. (RS)-1-(Phenylseleno)-2-propanol, (RS)-1a.
Oil; yield: 1.913g (89%); CAS NR: 25570-56-3; 1H
NMR (300MHz): d 1.27 (d, 3H, J = 6.2Hz), 2.46 (br
s, 1H), 2.88 (dd, 1H, J = 8.3, 12.7Hz), 3.10 (dd, 1H,
J = 3.9, 12.7Hz), 3.84–3.88 (m, 1H), 7.23–7.28 (m,
3H), 7.50–7.56 (m, 2H); 13C NMR (75MHz): d 22.4,
38.5 (J113CÀ77Se = 64Hz), 66.1, 127.3, 129.3, 129.2,
133.1; NMR 77Se (95MHz):
d 240.8; IR 3390,
3070, 3056, 3016, 2971, 2927, 1578, 1478, 1371, 736,
691cmÀ1; MS m/z (rel int): 216 (60), 215 (4), 172 (47),
158 (57), 157 (50), 91 (100), 77 (72), 78 (89), 59 (68),
51 (63), 45 (53); Anal. Calcd for C9H12OSe: C, 50.24;
H, 5.62. Found: C, 49.86; H, 5.63.
4.2.2.3. (RS)-1-(Phenylseleno)-3-methyl-2-butanol,
(RS)-1d. Oil; yield: 0.379g (78%); CAS NR: 68395-
1
4.2.1.2. (RS)-1-Phenyl-2-(phenylseleno)-ethanol, (RS)-
1e. Oil; yield: 1.800g (65%); CAS NR: 51558-95-3;
98-2; NMR H (500MHz): d 0.89–0.93 (m, 6H), 1.74–
1.80 (m, 1H), 2.89 (dd, 1H, J = 9.5, 12.7Hz), 3.17 (dd,
1H, J = 3.0, 12.7Hz), 3.40–3.44 (m, 1H), 7.23–7.28 (m,
3H), 7.50–7.54 (m, 2H); NMR 13C (125MHz): d 17.7,
18.7, 33.3, 34.9, 74.5, 127.2, 129.2, 129.3, 133.0; NMR
77Se (95MHz): d 240.8; IR 691, 737, 1472, 1578, 1801,
1874, 2874, 2960, 3429; MS m/z (rel int): 244 (57), 183
(4), 172 (71), 157 (72), 91 (74), 77 (76), 69 (100), 51
(60), 45 (44); Anal. Calcd for C11H16OSe: C, 54.32; H,
6.63. Found: C, 54.75; H, 7.05.
1
NMR H (300MHz): d 2.83 (d, 1H, J = 2.8Hz), 3.13
(dd, 1H, J = 9.3, 12.8Hz), 3.29 (dd, 1H J = 3.8,
12.8Hz), 4.73 (dd, 1H, J = 3.8, 9.3Hz), 7.24–7.33 (m,
8H), 7.52–7.55 (m, 2H); NMR 13C (75MHz): d 38.5,
72.3, 125.8, 127.4, 127.9, 128.5, 129.3, 133.1, 133.2,
142.5; NMR 77Se (95MHz): d 251.9; IR 693, 736,
1085, 1437, 1453, 1477, 1578, 2880, 2932, 2983,
3000, 3029, 3058, 3907cmÀ1; MS m/z (rel int): 278
(25), 277 (3), 172 (100), 157 (18), 121 (4), 107 (60),
91 (54), 79 (83), 77 (83); 51 (43), 43 (29); Anal. Calcd
for C14H14OSe: C, 60.66; H, 5.09. Found: C, 60.51; H,
5.34.
4.2.2.4.
(RS)-1-Hexyl-1-(phenylseleno)-2-propanol,
(RS)-1h. Diastereoisomeric mixture; oil; yield: 0514g
(86%); NMR 1H (300MHz): d 0.85–0.93 (m, 6H),
1.18–1.76 (m, 26H), 2.08 (br s, 1H), 2.12 (br s, 1H),
2.97–3.03 (m, 1H), 3.25–3.76 (m, 1H), 3.65–3.76 (m,
1H), 3.80–3.88 (m, 1H), 7.20–7.30 (m, 6H), 7.56–7.60
(m, 4H); NMR 13C (75MHz): d 14.0, 19.8, 20.5, 22.6,
28.1, 28.4, 29.0, 29.1, 31.1, 31.6, 31.7, 31.9, 57.8, 58.0,
68.9, 69.3, 127.5, 127.6, 129.0, 129.1, 129.6, 134.4,
134.9; MS m/z (rel int): 300 (30), 255 (6), 172 (5), 158
(59), 157 (24), 91 (16), 78 (49), 77 (40), 69 (100), 55
(96), 51 (20), 45 (63); Anal. Calcd for C15H24OSe: C,
60.19; H, 8.08. Found: C, 60.34; H, 8.37.
4.2.2. General procedure for the preparation of the
racemic substrates (RS)-1b–d, (RS)-1h and i. In a two
necked flask, under nitrogen, the appropriate seleno-
acetal (2mmol)2,17 was dissolved in dry THF (8mL).
n-Butyl lithium (2mmol in hexane) was added slowly
at À78ꢂC and the reaction mixture was stirred for
30min. To the solution was added the corresponding
aldehyde (propynaldehyde, isobutyraldehyde, heptalde-
hyde, acetaldehyde—2mmol) and the mixture was stir-
red for 20min at À78ꢂC and then for 1h at room
temperature. After this period, NH4Cl solution was
added and the reaction mixture was extracted with ethyl
acetate. The organic phase was washed with brine, dried
with MgSO4 and evaporated. The residue was purified
by silica gel column chromatography eluting with hex-
ane–ethyl acetate (85:15).
4.2.2.5. (RS)-1-Phenyl-1-(phenylseleno)-2-propanol,
(RS)-1i. Diastereoisomeric mixture; oil; yield: 0.512g
1
(88%); CAS NR: 623575-61-1; NMR H (200MHz): d
1.15 (d, 3H, J = 5.7Hz), d 1.24 (d, 3H, J = 5.7Hz),
1.95 (br s, 2H), 4.07–4.26 (m, 4H), 7.02–7.37 (m, 20H);
NMR 13C (75MHz): d 20.5, 20.6, 57.3, 60.1, 69.2,
69.6, 127.1, 127.4, 128.3, 128.4, 128.9, 129.0, 135.1,
135.5; MS m/z (rel int): 292 (11), 247 (4), 158 (30), 157
(15), 135 (86), 117 (51), 91 (62), 78 (32), 77 (39), 57
(73), 51 (25), 43 (100).
4.2.2.1. (RS)-1-(Phenyseleno)-2-pentanol, (RS)-1b.
1
Oil; yield: 0.350g (72%); NMR H (300MHz): d 0.89
(t, 3H, J = 7.20Hz), 1.33–1.37 (m, 1H), 1.44–1.54 (m,
3H), 2.18 (br s, 1H), 2.88 (dd, 1H, J = 8.61, 12.73Hz),
3.14 (dd, 1H, J = 3.51, 12.73Hz), 3.66–3.71 (m, 1H),
7.24–7.27 (m, 3H), 7.52–7.53 (m, 2H); NMR 13C
(75MHz): d 14.2, 19.2, 37.5 (J113CÀ77Se = 64Hz), 39.0,
69.91, 127.5, 129.4, 129.7, 133.3; NMR 77Se (95MHz):
d 234.2; IR 691, 737, 1436, 1459, 1474, 1578, 2870,
2928, 2958, 3063, 3401cmÀ1; MS m/z (rel int): 244
(60), 243 (4), 172 (100), 158 (63), 157 (61), 91 (86), 78
(81), 77 (74), 69 (44), 55 (85), 51 (51), 45 (90), 41 (89);
Anal. Calcd for C11H16OSe: C, 54.32; H, 6.63. Found:
C, 54.08; H, 6.85.
4.2.3. General procedure for the preparation of the
racemic substrate (RS)-1f. To a suspension of ele-
mental selenium (5mmol) in dry THF (25mL) under
nitrogen and with magnetic stirring was added n-
butyllithium (in hexane—5mmol). A yellow solution
was formed. To this solution was added styrene oxide
(5mmol). The mixture was then heated at reflux for
24h. After this period, the mixture was cooled to room
temperature, treated with NH4Cl solution and extracted
with ethyl acetate. The organic phase was washed with