3760 J . Org. Chem., Vol. 62, No. 11, 1997
Notes
to yield 680 mg (79%) of alcohol 5f: Rf ) 0.47 (20% EtOAc/
hexanes); IR (neat) 3380, 3076, 1630, 1032, 991 cm-1; 1H NMR
(200 MHz, CDCl3) δ 5.90-5.68 (1 H, m), 4.91-4.74 (2 H, m),
1.94-1.42 (12 H, m), 0.61-0.50 (2 H, m), -0.04 (6 H, s); 13C
NMR (75 MHz, CDCl3) δ 135.0, 112.8, 83.3, 39.2, 35.1, 24.0, 23.0,
8.9, -4.0; CIMS m/z (relative intensity) 195 (37, M+ - OH), 171
(11, M+ - allyl), 169 (18), 153 (14), 101 (16), 99 (21), 75 (100).
(4 × 30 mL). The combined organic extracts were washed with
brine (50 mL), dried (Na2SO4), and concentrated. The crude
residue was purified by silica gel chromatography (10% EtOAc/
hexanes) to yield 957 mg (69%) of alcohol 13: Rf ) 0.47 (20%
EtOAc/hexanes); 1H NMR (200 MHz, CDCl3) δ 5.92-5.67 (2 H,
m), 5.09-4.75 (4 H, m), 3.66-3.55 (1 H, m), 2.21-2.07 (2 H, m),
1.58-1.24 (9 H, m), 0.59-0.40 (2 H, m), -0.05 (6 H, s); 13C NMR
(90 MHz, CDCl3) δ 138.6, 134.7, 114.6, 112.8, 71.1, 41.4, 36.5,
30.0, 23.2, 21.3, 14.9, -3.5; CIMS m/z (relative intensity) 209
(M+ - OH), 185 (41), 169 (94), 167 (100), 141 (76), 129 (40), 127
(38), 101 (20), 75 (96).
P r epar ation of 1-[2′-(Allyldim eth ylsilyl)eth yl]cycloh exan -
1-ol (5g). The general procedure was followed using cyclohex-
anone (237 mg, 2.41 mmol), 9 mL of THF, and 9 mL of Grignard
reagent 4 (∼0.53 M, 4.8 mmol). The crude product was purified
by silica gel chromatography (10% EtOAc/hexanes) to yield 385
mg (71%) of alcohol 5g: Rf ) 0.51 (20% EtOAc/hexanes); IR (film)
P r ep a r a tion of 1-(Allyld im eth ylsilyl)h exa n -4-ol (12).
The general procedure for epoxide opening was followed using
CuI (188 mg, 0.99 mmol), 15 mL of Grignard reagent 4 (∼0.60
M, 9.0 mmol), 1,2-epoxybutane (10, 419 mg, 5.8 mmol), and 45
mL of THF. The crude residue was purified by silica gel
chromatography (10% EtOAc/hexanes) to yield 815 mg (70%) of
alcohol 12: Rf ) 0.42 (20% EtOAc/hexanes); IR (film) 2932, 1629,
3459, 3078, 2908, 1629, 1448, 1260, 1036, 993 cm-1 1H NMR
;
(200 MHz, CDCl3) δ 5.88-5.67 (1 H, m), 4.92-4.78 (2 H, m),
1.61-1.19 (14 H, m), 0.59-0.40 (2 H, m), -0.04 (6 H, s); 13C
NMR (75 MHz, CDCl3) δ 134.8, 113.2, 72.1, 37.3, 27.9, 25.8, 23.7,
21.1, 6.0, -4.9. CIMS m/z (relative intensity) 209 (40, M+
OH), 183 (38), 167 (38), 141 (13), 101 (42), 75 (100).
-
1
1458, 1250, 929 cm-1; H NMR (200 MHz, CDCl3) δ 5.87-5.65
(1 H, m), 4.90-4.78 (2 H, m), 3.58-3.46 (1 H, m), 1.54-1.24 (8
H, m), 0.91 (3 H, t, J ) 7.4 Hz), 0.57-0.43 (2 H, m), -0.05 (6 H,
s). 13C NMR (75 MHz, CDCl3) δ 134.8, 112.6, 73.0, 40.9, 30.2,
23.2, 21.3, 19.9, 9.9, -3.6; CIMS m/z (relative intensity) 183 (12,
M+ - OH), 157 (18), 143 (82), 101 (38), 84 (100).
P r ep a r a tion of 1-(Allyld im eth ylsilyl)-3-p r op ylh exa n -3-
ol (5h ). The general procedure was followed using 4-heptanone
(343 mg, 3.00 mmol), 16 mL of THF, and 12 mL of Grignard
reagent 4 (∼0.50 M, 6.0 mmol). The crude product was purified
by silica gel chromatography (10% EtOAc/hexanes) to yield 586
mg (81%) of compound 5h : Rf ) 0.52 (20% EtOAc/hexanes); IR
Gen er a l P r oced u r e for Con ver sion of Allylsila n es to
Alcoh ols via F lu or osila n es. P r ep a r a tion of 1-P h en yl-1,3-
p r op a n ed iol (7a ). The benzyl alcohol 5a (210 mg, 0.90 mmol)
was dissolved in CHCl3 (12 mL) and added to a 50 mL Teflon
Erlenmeyer flask under argon. The solution was stirred for 15
min, KHF2 (150 mg, 1.92 mmol) and TFA (0.3 mL, 3.89 mmol)
were added, and the reaction mixture was stirred at rt for 18 h.
The reaction mixture was transferred to a glass round-bottomed
flask and concentrated by rotary evaporation to yield the crude
fluorosilane. THF (7 mL), methanol (7 mL), and NaHCO3 (350
mg, 4.17 mmol) were added, and stirring was resumed. After
15 min, H2O2 (1.5 mL, 16.3 mmol) was added dropwise, a
condenser was fitted onto the flask, and the mixture was warmed
at a gentle reflux for 18 h. The mixture was cooled to rt and
concentrated to one-quarter volume by rotary evaporation.
EtOAc (25 mL) and Na2SO4 were added, and the mixture was
allowed to stand at rt for 30 min. The mixture was filtered
through Celite and concentrated by rotary evaporation. The
crude residue was purified by silica gel chromatography (50%
EtOAc/hexanes) to yield 108 mg (78%) of known7 1-phenyl-1,3-
propanediol (7a ): 1H NMR (200 MHz, CDCl3) δ 7.36 (5 H, s),
4.81 (1 H, m), 3.41 (2 H, bs), 2.41-2.07 (5 H, m).
P r ep a r a tion of 1-Cycloh exyl-1,3-p r op a n ed iol (7b). The
general procedure was followed using 1-(allyldimethylsilyl)-3-
cyclohexylpropan-3-ol (5b, 140 mg, 0.58 mmol), KHF2 (105 mg,
1.34 mmol), TFA (0.35 mL, 4.54 mmol), and CHCl3 (10 mL). The
crude fluorosilane (∼110 mg) was oxidized using THF (5 mL),
methanol (5 mL), NaHCO3 (210 mg, 2.50 mmol), and H2O2 (1.2
mL, 11.7 mmol). The crude residue was purified by silica gel
chromatography (50% EtOAc/hexanes) to yield 60 mg (65%) of
known8 compound 7b: 1H NMR (200 MHz, CDCl3) δ 3.92-3.80
(2 H, m), 3.63 (1 H, q, J ) 9 Hz), 2.80 (2 H, bs), 1.88-1.61 (7 H,
m), 1.39-0.94 (6 H, m).
P r ep a r a tion of 1,3-Hexa n ed iol (7c). The general proce-
dure was followed using 1-(allyldimethylsilyl)hexan-3-ol (5c, 230
mg, 1.15 mmol), KHF2 (190 mg, 2.43 mmol), TFA (0.5 mL, 6.49
mmol), and CHCl3 (10 mL). The crude fluorosilane (∼200 mg)
was oxidized using THF (6 mL), methanol (6 mL), NaHCO3 (490
mg, 5.83 mmol), and H2O2 (2.4 mL, 22.9 mmol). The crude
residue was purified by silica gel chromatography (50% EtOAc/
hexanes) to yield 107 mg (79%) of known9 compound 7c: 1H
NMR (200 MHz, CDCl3) δ 3.81 (3 H, m), 2.15 (2 H, bs), 1.74-
1.58 (2 H, m), 1.49-1.14 (4 H, m), 0.90 (3 H, t, J ) 8 Hz).
P r ep a r a tion of 4-Meth yl-1,3-p en ta n ed iol (7d ). The gen-
eral procedure was followed using 1-(allyldimethylsilyl)-4-me-
thylpentan-3-ol (5d , 266 mg, 1.33 mmol), KHF2 (215 mg, 2.75
mmol), TFA (0.45 mL, 5.84 mmol), and CHCl3 (15 mL). The
crude fluorosilane (∼230 mg) was oxidized using THF (9 mL),
methanol (9 mL), NaHCO3 (490 mg, 5.83 mmol), and 30% H2O2
(2.6 mL, 25.4 mmol). The crude product was purified by silica
gel chromatography (50% EtOAc/hexanes) to yield 98 mg (66%)
of known10 compound 7d : 1H NMR (200 MHz, CDCl3) δ 3.82 (2
H, t, J ) 6.0 Hz), 3.60 (1 H, q, J ) 5.6 Hz), 3.24 (2 H, br s),
1.69-1.56 (3 H, m), 0.87 (6 H, dd, J ) 5.8, 2.4 Hz).
(neat) 3412, 2957, 1631, 1456, 1249, 1158, 974 cm-1 1H NMR
;
(200 MHz, CDCl3) δ 5.89-5.65 (1 H, m), 4.90-4.76 (2 H, m),
1.52 (2 H, t, J ) 8.4 Hz), 1.41-1.16 (10 H, m), 1.07 (1 H, bs),
0.88 (6 H, t, J ) 6.8 Hz), 0.52-0.34 (2 H, m), -0.05 (6 H, s); 13
C
NMR (75 MHz, CDCl3) δ 134.8, 113.1, 74.9, 41.0, 32.8, 21.2, 16.7,
14.7, 7.8, -3.9; CIMS m/z (relative intensity) 225 (14, M+ - OH),
201 (8, M+ - allyl), 199 (48), 157 (22), 127 (6), 115 (52), 101
(30), 75 (90), 73 (100).
P r epar ation of 3-[2′-(Allyldim eth ylsilyl)eth yl]cycloh exan -
1-on e (8). A 250 mL flask was charged with CuBr‚Me2S (498
mg, 2.42 mmol), flame dried under vacuum, and returned to an
argon atmosphere. THF (45 mL) was added, stirring was
started, and the mixture was cooled to -78 °C. Grignard reagent
4 (18 mL, ∼0.54 M, 9.7 mmol) was added dropwise, resulting in
a cloudy, dark green solution. After the mixture was stirred
for 1 h, HMPA (1.7 mL, 9.7 mmol) was added, followed by the
dropwise addition of a solution of 2-cyclohexen-1-one (467 mg,
4.85 mmol) and freshly distilled chlorotrimethylsilane (1.11 g,
10.2 mmol) in THF (7 mL). The mixture was stirred at -78 °C
for 3 h, warmed to -50 °C, and stirred for an additional 3 h.
Water (30 mL) was added, and the mixture was stirred at rt
open to the atmosphere for 1 h. NH4OH (10%) in saturated
NH4Cl solution (100 mL) was added, and the mixture was stirred
for 1 h, resulting in a royal blue solution. The layers were
separated, and the aqueous phase was extracted with ether (4
× 30 mL). The combined organic extracts were washed with
water (4 × 25 mL), dried (Na2SO4), and concentrated. The crude
residue was purified by silica gel chromatography (10% EtOAc/
hexanes) to yield 832 mg (76%) of the cyclohexanone 8: Rf )
0.49 (20% EtOAc/hexanes); IR (film) 3059, 1696, 1629, 1035, 914
1
cm-1; H NMR (200 MHz, CDCl3) δ 5.90-5.63 (1 H, m), 4.92-
4.74 (2 H, m), 2.47-2.19 (2 H, m), 2.11-1.82 (3 H, m), 1.71-
1.40 (5 H, m), 1.36-1.15 (3 H, m), 0.56-0.38 (2 H, m), -0.09 (6
H, s); 13C NMR (75 MHz, CDCl3) δ 211.8, 134.3, 113.1, 47.6, 41.8,
41.2, 31.6, 30.1, 25.0, 20.9, 11.4, 9.3, -2.0; CIMS m/z (relative
intensity) 209 (36, M+ - Me), 183 (100, M+ - allyl), 169 (15),
155 (18), 109 (38), 75 (34), 73 (12).
Gen er a l P r oced u r e for Cu I-Ca ta lyzed Op en in g of a n
Ep oxid e w ith Gr ign a r d Rea gen t 4. P r ep a r a tion of 1-(Al-
lyld im eth ylsilyl)-7-octen -4-ol (13). A 250 mL flask was
charged with CuI (184 mg, 0.97 mmol), flame-dried under
vacuum, and returned to an argon atmosphere. THF (40 mL)
was added, stirring was started, and the mixture was cooled to
-78 °C. Grignard reagent 4 (17 mL, ∼0.54 M, 9.2 mmol) was
added dropwise, resulting in a cloudy gray solution. After the
mixture was stirred for 1 h, a solution of 1,2-epoxy-5-hexene (11,
601 mg, 6.1 mmol) in THF (7 mL) was added dropwise. The
mixture was stirred at -78 °C for 3 h and then warmed to -30
°C and stirred for an additional 3 h, resulting in a dark green
solution. NH4OH (10%) in saturated NH4Cl solution (100 mL)
was added, and the mixture was stirred at rt for 1 h. The layers
were separated, and the aqueous layer was extracted with ether