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H. Takamura et al. / Tetrahedron 65 (2009) 7449–7456
with saturated aqueous NH4Cl. The mixture was diluted with Et2O.
The organic layer was washed with water and brine, and then dried
over Na2SO4. Concentration and column chromatography (hexane/
Et2O, 0.87 mL, 0.870 mmol) at 0 ꢁC. After the mixture was stirred at
0 ꢁC for 20 min, the reaction was quenched with MeOH. The mix-
ture was filtered through a Celite pad and washed with Et2O. The
organic layer was washed with water and brine, and then dried
over Na2SO4. Concentration and short column chromatography
(hexane/EtOAc¼20:1) gave the corresponding alcohol (249 mg) as
a diastereomixture, which was used in the next reaction without
further purification.
EtOAc¼100:1) gave the corresponding silyl ether (264 mg, 95%).
28
Colorless oil; Rf¼0.80 (hexane/EtOAc¼10:1); [
a
]
D
ꢀ4.4 (c 3.00,
CHCl3); IR (neat) 2930, 1641 cmꢀ1
;
1H NMR (400 MHz, CDCl3)
d
7.68–7.63 (m, 4H), 7.42–7.30 (m, 6H), 5.76–5.65 (m, 1H), 5.19 (d,
J¼9.0 Hz, 1H), 4.94 (d, J¼14.9 Hz, 1H), 4.94 (d, J¼11.7 Hz, 1H), 4.41–
4.35 (m, 1H), 3.86–3.79 (m, 1H), 3.62–3.55 (m, 2H), 2.32–2.19 (m,
2H), 2.06–1.93 (m, 2H), 1.59 (ddd, J¼13.9, 7.3, 3.2 Hz, 1H), 1.41–1.33
(m, 1H), 1.14 (s, 3H), 1.04 (s, 9H), 0.88 (s, 9H), 0.86 (s, 9H), 0.04 (s,
3H), 0.03 (s, 3H), 0.01 (s, 3H), 0.01 (s, 3H); 13C NMR (100 MHz,
To a solution of the alcohol (249 mg) obtained above in CH2Cl2
(6.0 mL) were added pyridine (0.94 mL, 11.6 mmol) and Dess–
Martin periodinane (1.20 g, 2.90 mmol) at room temperature.
After being stirred at room temperature for 3 h, the mixture was
filtered through a silica gel pad and washed with Et2O. Concen-
tration and column chromatography (hexane/EtOAc¼40:1) gave
CDCl3)
d 135.9, 135.8, 134.6, 134.4, 134.4, 132.7, 130.7, 129.4, 129.2,
127.4, 127.2, 116.7, 70.1, 67.8, 59.7, 48.5, 43.1, 39.2, 27.1, 26.0, 19.4,
18.3, 18.1, 17.0, ꢀ4.2, ꢀ4.7, ꢀ5.2, ꢀ5.2; HRMS (ESI) calcd for
C39H66O3Si3Na (MþNa)þ 689.4218, found: 689.4274.
ketone 15 (192 mg, 77% in two steps). Colorless oil; Rf¼0.62
25
(hexane/EtOAc¼4:1); [
a
]
ꢀ1.7 (c 3.28, CHCl3); IR (neat) 2954,
D
To a solution of the silyl ether (145 mg, 0.214 mmol) obtained
above in CH2Cl2 (1.4 mL) and MeOH (0.8 mL) was added CSA
1690, 1618 cmꢀ1; 1H NMR (400 MHz, CDCl3)
d 6.06 (br s, 1H), 5.77
(ddt, J¼17.2, 10.2, 6.9 Hz, 1H), 5.15–5.07 (m, 2H), 4.05–3.99 (m,
1H), 3.64 (t, J¼6.4 Hz, 2H), 3.14 (dt, J¼6.8, 1.2 Hz, 2H), 2.25 (d,
J¼6.4 Hz, 2H), 2.12 (d, J¼1.2 Hz, 3H), 1.63–1.58 (m, 2H), 0.86 (s,
9H), 0.84 (s, 9H), 0.02 (s, 3H), 0.01 (s, 3H), 0.01 (s, 3H), ꢀ0.01 (s,
(10.0 mg, 42.9 m
mol) at 0 ꢁC. After the mixture was stirred at 0 ꢁC for
10 min, the reaction was quenched with Et3N. Concentration and
column chromatography (hexane/EtOAc¼50:1, 10:1) gave alcohol
12 (42.8 mg, 36%, 82% based on recovered starting material) and silyl
3H); 13C NMR (100 MHz, CDCl3)
d 197.8, 156.4, 131.2, 124.9, 118.3,
ether (80.9 mg, 56% recovery). For alcohol 12: colorless oil; Rf¼0.22
67.7, 59.4, 49.5, 49.2, 40.4, 25.9, 25.9, 20.0, 18.3, 18.1, ꢀ4.5, ꢀ4.5,
ꢀ5.3; HRMS (ESI) calcd for C23H46O3Si2Na (MþNa)þ 449.2883,
found: 449.2933.
26
(hexane/EtOAc¼10:1); [
a
]
ꢀ3.7 (c 1.15, CHCl3); IR (neat) 3445,
D
3072, 2930, 1640 cmꢀ1 1H NMR (400 MHz, CDCl3)
; d 7.67–7.62 (m,
4H), 7.41–7.30 (m, 6H), 5.73–5.62 (m,1H), 5.17 (dd, J¼8.8,1.2 Hz,1H),
4.93 (d, J¼11.2 Hz, 1H), 4.93 (d, J¼16.1 Hz, 1H), 4.40–4.35 (m, 1H),
3.91–3.85 (m,1H), 3.74 (br s,1H), 3.61 (br s,1H), 2.39 (br s,1H), 2.32–
2.18 (m, 2H), 2.05 (d, J¼7.1 Hz, 2H), 1.67–1.59 (m, 1H), 1.45–1.37 (m,
1H), 1.11 (d, J¼1.2 Hz, 3H), 1.02 (s, 9H), 0.87 (s, 9H), 0.06 (s, 3H), 0.06
4.12. Homoallylic alcohol 16
To a solution of ketone 15 (43.7 mg, 0.102 mmol) and (S)-2-
methyl-CBS-oxazaborolidine (56.8 mg, 0.205 mmol) in toluene
(s, 3H); 13C NMR (100 MHz, CDCl3)
d
135.8, 135.8,134.5, 134.4, 134.3,
(1.0 mL) was added BH3$SMe2 (20
m
L, 0.205 mmol) at ꢀ78 ꢁC. After
132.0,131.1,129.4,129.3,127.4,127.2,116.8, 70.8, 69.9, 60.3, 47.3, 43.1,
36.7, 27.0, 25.9, 19.4, 18.0, 17.0, ꢀ4.3, ꢀ4.8; HRMS (ESI) calcd for
C33H52O3Si2Na (MþNa)þ 575.3353, found: 575.3356.
the mixture was stirred at ꢀ30 ꢁC for 18 h, the reaction was
quenched with MeOH. The mixture was filtered through a silica gel
pad and washed with Et2O. Concentration and column chroma-
tography (hexane/EtOAc¼30:1, 10:1) gave allylic alcohol 16
26
4.10. Diol 14
(35.0 mg, 80%). Colorless oil; Rf¼0.45 (hexane/EtOAc¼4:1); [
a]
D
þ19.5 (c 1.46, CHCl3); IR (neat) 3366, 2929, 1641 cmꢀ1
;
1H NMR
To a mixture of alcohol 12 (12.2 mg, 22.1
phenyl selenocyanate (10.0 mg, 44.2 mol) in THF (0.5 mL) were
added pyridine (18 L, 0.221 mmol) and tributylphosphine (11 L,
44.2 mol). The mixture was stirred at room temperature for
30 min. To the resulting mixture was added 30% H2O2 (50 L) at
mmol) and o-nitro-
(400 MHz, CDCl3)
d
5.85–5.75 (m, 1H), 5.21 (d, J¼8.6 Hz, 1H), 5.14–
m
5.08 (m, 2H), 4.41–4.36 (m, 1H), 3.99–3.93 (m, 1H), 3.64 (t, J¼6.5 Hz,
2H), 2.26 (t, J¼6.7 Hz, 2H), 2.20 (dd, J¼13.4, 5.6 Hz, 1H), 2.12 (dd,
J¼13.4, 6.8 Hz, 1H), 1.69 (s, 3H), 1.65–1.50 (m, 2H), 0.87 (s, 9H), 0.86
(s, 9H), 0.04 (s, 3H), 0.03 (s, 3H), 0.02 (s, 6H); 13C NMR (100 MHz,
m
m
m
m
room temperature. The stirring was continued at room tempera-
ture for 1 h. The mixture was diluted with Et2O. The organic layer
was washed with water, saturated aqueous Na2SO3, and brine, and
then dried over Na2SO4. Concentration and short column chroma-
tography (hexane/EtOAc¼100:1) gave alkene 13 (11.8 mg), which
was used in the next reaction without further purification.
CDCl3) d 136.0, 134.4, 129.7, 117.9, 67.8, 67.6, 59.8, 47.9, 42.1, 39.9,
26.0, 26.0, 18.3, 18.1, 17.4, ꢀ4.3, ꢀ4.5, ꢀ5.2, ꢀ5.2; HRMS (ESI) calcd
for C23H48O3Si2Na (MþNa)þ 451.3040, found: 451.3057.
4.13. Silyl ether 17
To a solution of alkene 13 (11.8 mg) obtained above inTHF (0.5 mL)
wasaddedTBAF(1.0 MsolutioninTHF, 0.44 mL,0.440 mmol), andthe
mixturewasstirredat40 ꢁCfor19 h. Themixturewasfilteredthrough
a silica gel pad and washed with EtOAc. Concentration and column
To a solution of alcohol 16 (35.0 mg, 81.6
(1.0 mL) were added imidazole (13.9 mg, 0.204 mmol) and TBDPSCl
(43 L, 0.164 mmol) at room temperature. After the mixture was
stirred at room temperature for 2 h, the reaction was quenched
with saturated aqueous NH4Cl. The mixture was diluted with Et2O.
The organic layer was washed with water and brine, and then dried
over Na2SO4. Concentration and column chromatography (hexane/
mmol) in CH2Cl2
m
chromatography (hexane/EtOAc¼3:1) gave diol 14 (2.6 mg, 65% in
24
two steps). Colorless oil; Rf¼0.18 (hexane/EtOAc¼1:1); [
a
]
ꢀ19.8 (c
D
0.22, CHCl3); IR (neat) 3366, 2929, 1641 cmꢀ1
;
1H NMR (400 MHz,
CD3OD)
d
5.84 (ddd, J¼16.6,10.5, 6.1 Hz,1H), 5.82–5.74 (m,1H), 5.23–
EtOAc¼100:1) gave silyl ether 17 (53.1 mg, 98%). Colorless oil;
24
5.18 (m, 1H), 5.21 (dt, J¼17.1, 1.7 Hz, 1H), 5.09–4.99 (m, 3H), 4.36 (dt,
J¼8.8, 6.6 Hz, 1H), 4.20 (dt, J¼7.6, 6.4 Hz, 1H), 2.33–2.15 (m, 4H), 1.71
Rf¼0.80 (hexane/EtOAc¼10:1); [
a]
þ25.4 (c 0.63, CHCl3); IR (neat)
D
2929 cmꢀ1 1H NMR (400 MHz, CDCl3)
; d 7.67–7.62 (m, 4H), 7.39–
(d, J¼1.2 Hz, 3H); 13C NMR (100 MHz, CD3OD)
d
142.1, 135.8, 135.4,
7.32 (m, 6H), 5.76–5.66 (m, 1H), 5.21 (d, J¼8.6 Hz, 1H), 4.93 (d,
J¼11.9 Hz, 1H), 4.92 (d, J¼15.1 Hz, 1H), 4.37 (dt, J¼8.8, 6.1 Hz, 1H),
3.89–3.83 (m, 1H), 3.62–3.58 (m, 2H), 2.29–2.16 (m, 2H), 2.09 (dd,
J¼13.5, 4.8 Hz, 1H), 1.94 (dd, J¼13.5, 7.7 Hz, 1H), 1.59–1.51 (m, 1H),
1.45–1.37 (m, 1H), 1.17 (s, 3H), 1.02 (s, 9H), 0.88 (s, 9H), 0.85 (s, 9H),
131.6, 117.2, 114.5, 71.9, 68.8, 43.2, 17.0; HRMS (ESI) calcd for
C11H18O2Na (MþNa)þ 205.1204, found: 205.1228.
4.11. Ketone 15
0.06 (s, 6H), 0.02 (s, 6H); 13C NMR (100 MHz, CDCl3)
d 135.9, 135.8,
To a solution of aldehyde 10 (224 mg, 0.580 mmol) in THF
(6.0 mL) was added allylmagnesium bromide (1.0 M solution in
134.8, 134.5, 134.4, 132.6, 130.5, 129.4, 129.2, 127.3, 127.2, 116.2, 70.1,
67.7, 59.8, 47.8, 43.1, 39.5, 27.1, 26.0, 26.0, 19.4, 18.3, 18.1, 17.0, 1.1,