Neopentyl-Type Halogenated Cyclopentanoids
J . Org. Chem., Vol. 61, No. 4, 1996 1351
5.76-5.96 (1H, m), 7.30-7.75 (10H, m); 13C NMR (75 MHz,
CDCl3) δ 1.5, 2.2, 19.4, 27.0, 31.5, 32.0, 66.9, 114.2, 118.1,
bu ta n ol (19). To a stirred suspension of cerium chloride (6.63
g, 26.9 mmol) in THF (80 mL) was added a solution of
isopropenylmagnesium bromide [prepared from magnesium
(1.44 g, 19.1 mmol) and 2-bromopropene (2.39 mL, 26.9 mmol)]
in THF (40 mL) at -78 °C. After stirring had been continued
for 1 h, a solution of cyclobutanone 14 (3.01 g, 7.90 mmol) in
Et2O (20 mL) was added dropwise to this reaction mixture at
the same temperature, and the temperature was then raised
to rt in 3 h. The reaction mixture was treated with saturated
aqueous NH4Cl and extracted with Et2O. The combined
extracts were washed with saturated aqueous NaCl. The
residue upon workup was chromatographed on silica gel with
hexane-AcOEt (97:3 v/v) as eluant to give isopropenylcyclobu-
126.8, 127.6, 129.5, 134.0, 135.7, 139.2; MS m/ z 319 (M+
-
57); HRMS calcd for C21H23OSi 319.1518 (M+ - 57). found
319.1501.
2-Cyclop r op ylid en e-5-h exen ol (13). To a stirred solution
of silyl ether 12 (4.29 g, 11.4 mmol) in THF (10 mL) was added
1 M solution of nBu4NF in THF (20.0 mL, 20.0 mmol) at rt,
and stirring was continued for 3.5 h at the same temperature.
The reaction mixture was diluted with water and extracted
with CH2Cl2. The combined extracts were washed with
saturated aqueous NaCl. The residue upon workup was
chromatographed on silica gel with hexane-AcOEt (95:5 v/v)
as eluant to give alcohol 13 (1.57 g 100%) as a colorless oil:
IR (neat) 3320, 1635 cm-1; 1H NMR (300 MHz, CDCl3) δ 1.01-
1.19 (4H, m), 1.55 (1H, t, J ) 6.0 Hz), 2.24-2.41 (4H, m), 4.24
(2H, d, J ) 6.0 Hz), 4.95 (1H, dd, J ) 1.5 and 9.9 Hz), 5.03
(1H, dd, J ) 1.5 and 17.3 Hz), 5.76-5.94 (1H, m); 13C NMR
(75 MHz, CDCl3) δ 1.3, 1.4, 31.8, 32.0, 65.8, 114.5, 117.8, 127.3,
138.7; MS m/ z 137 (M+ - 1); HRMS calcd for C9H13O 137.0966
(M+ - 1), found 137.0962.
tanol 19 (2.35 g, 71%) as a colorless oil: IR (neat) 3450 cm-1
;
1H NMR (300 MHz, CDCl3) δ 1.04 (9H, s), 1.21-1.93 (10H,
m), 1.77 (3H, s), 2.10-2.24 (1H, m), 2.33-2.47 (1H, m), 3.66
(2H, t, J ) 6.2 Hz), 4.79 and 4.90 (each 1H, each br s), 7.30-
7.71 (10H, m); 13C NMR (125 MHz, CDCl3) δ 18.2, 19.3, 21.5,
23.4, 27.0, 29.3, 31.6, 32.8, 42.8, 63.9, 79.7, 109.2, 127.8, 129.5,
134.2, 135.7, 149.4; MS m/ z 365 (M+ - 57); HRMS calcd for
C23H29O2Si 365.1937 (M+ - 57), found 365.1935.
(1R,2S)-2-Hep tyl-1-isop r op en ylcyclobta n ol (20): yield
Gen er a l P r oced u r e for th e P r ep a r a tion of Cyclobu -
ta n on e Der iva tives. P r ep a r a tion of 2-[4-(ter t-Bu tyl-
d ip h en ylsiloxy)bu tyl]cyclobu ta n on e (14). To a stirred
solution of cyclopropylidene 9 (4.3 g, 11.8 mmol) in CH2Cl2 (40
mL) was added m-CPBA (3.31 g, of 80% active, 15.3 mmol) at
0 °C, and stirring was continued for 17 h at rt. The reaction
mixture was diluted with CH2Cl2 and washed with 10% NaOH
and saturated aqueous NaCl. The residue upon workup was
chromatographed on silica gel with hexane-AcOEt (99:1 v/v)
as eluant to give cyclobutanone 14 (3.01 g, 67%) as a colorless
79%; colorless oil; IR (neat) 3480 cm-1 1H NMR (300 MHz,
;
CDCl3) δ 0.88 (3H, t, J ) 5.9 Hz), 1.13-1.94 (16H, m), 1.78
(3H, s), 2.11-2.26 (1H, m), 2.35-2.48 (1H, m), 4.80 and 4.92
(each 1H, each br s); 13C NMR (75 MHz, CDCl3) δ 14.0, 17.9,
21.3, 22.6, 27.1, 29.3, 29.4, 29.8, 31.4, 32.0, 42.8, 79.4, 108.8,
149.4; MS m/ z 210 (M+); HRMS calcd for C14H26O 210.1984
(M+), found 210.1955.
(1R,2R)-1-Isop r op en yl-2-p h en ylcyclobu ta n ol (21): yield
63%; colorless oil; IR (neat) 3450 cm-1 1H NMR (300 MHz,
;
1
oil: IR (neat) 1770 cm-1; H NMR (300 MHz, CDCl3) δ 1.05
CDCl3) δ 1.46 (1H, s), 1.82 (3H, s), 1.87-2.03 (1H, m), 2.04-
2.18 (1H, m), 2.21-2.59 (2H, m), 3.80 (1H, t, J ) 8.4 Hz), 4.86
and 5.03 (each 1H, each br s), 7.17-7.38 (5H, m); 13C NMR
(75 MHz, CDCl3) δ 18.5, 20.7, 31.1, 47.3, 80.8, 109.9, 126.7,
(9H, s), 1.32-1.79 (7H, m), 2.05-2.23 (1H, m), 2.81-3.09 (2H,
m), 3.16-3.32 (1H, m), 3.65 (2H, t, J ) 5.9 Hz), 7.33-7.73
(10H, m); MS m/ z 323 (M+ - 57). Anal. Calcd for C24H32O2-
Si: C, 75.74; H, 8.47. Found: C, 75.48; H, 8.47.
128.4, 138.7, 148.9; MS m/ z 188 (M+); HRMS calcd for C13H16
O
188.1201, found 188.1224.
[(1S,2S) a n d (1R,2S)]-2-(3-Bu t en yl)-2-[(ter t-b u t yld i-
2-Hep tylcyclobu ta n on e (15): yield 34%; colorless oil; IR
(neat) 1780 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.88 (3H, t, J
) 7.3 Hz), 1.12-1.82 (13H, m), 2.08-2.29 (1H, m), 2.80-3.11
(2H, m), 3.19-3.35 (1H, m); MS m/ z 168 (M+); HRMS calcd
for C11H20O 168.1514 (M+), found 168.1541.
2-P h en ylcyclobu ta n on e (16): yield 35%; colorless oil; IR
(neat) 1785 cm-1; 1H NMR (300 MHz, CDCl3) δ 2.16-2.34 (1H,
m), 2.45-2.63 (1H, m), 2.74-3.11 (1H, m), 3.13-3.33 (1H, m),
4.47-4.60 (1H, m), 7.19-7.44 (5H, m); 13C NMR (75 MHz,
CDCl3) δ 17.7, 44.9, 64.6, 127.0, 128.6, 136.5, 207.7; MS m/ z
146 (M+); HRMS calcd for C10H10O 146.0732 (M+), found
146.0713.
m eth ylsiloxy)m eth yl]-1-isopr open ylcyclobu tan ol (22 an d
23). 22: yield 76%; colorless oil; IR (neat) 3440, 1630 cm-1
;
1H NMR (500 MHz, CDCl3) δ -0.01 (3H, s), 0.00 (3H, s), 0.85
(9H, s), 1.25-1.33 (1H, m), 1.56 (1H, s), 1.65-1.84 (4H, m),
1.77 (3H, s), 1.86-1.96 (1H, m), 1.97-2.06 (1H, m), 2.32-2.45
(1H, m), 3.36 and 3.52 (each 1H, each d, J ) 10.4 Hz), 4.84
and 4.87 (each 1H, each d, J ) 1.2 Hz), 4.91 (1H, dd, J ) 1.2
and 9.8 Hz), 5.00 (1H, dd, J ) 1.2 and 17.1 Hz), 5.77-5.91
(1H, m); 13C NMR (125 MHz, CDCl3) δ -5.8, -5.7, 18.3, 19.8,
23.1, 25.9, 28.5, 28.9, 29.4, 50.8, 64.6, 81.7, 111.0, 114.0, 139.6,
147.3; MS m/ z 253 (M+ - 57); HRMS calcd for C14H25O2Si
253.1624 (M+ - 57), found 253.1630.
2-(3-Bu ten yl)-2-(h yd r oxym eth yl)cyclobu ta n on e (17):
1
yield 53%; colorless oil; IR (neat) 3430, 1765, 1635 cm-1; H
1
NMR (300 MHz, CDCl3) δ 1.58-2.30 (7H, m), 2.92-3.04 (2H,
m), 3.65 and 3.79 (each 1H, each dd, J ) 5.1 and 10.8 Hz),
4.97 (1H, dd, J ) 1.5 and 8.8 Hz), 5.04 (1H, dd, J ) 1.5 and
16.9 Hz), 5.71-5.93 (1H, m); 13C NMR (75 MHz, CDCl3) δ 18.9,
28.4, 30.5, 43.3, 64.0, 69.9, 114.9, 137.8, 215.7; MS m/ z 154
(M+); HRMS calcd for C9H14O2 154.0994, found 154.1012.
2-(3-Bu ten yl)-2-[(ter t-bu tyld im eth ylsiloxy)m eth yl]cy-
clobu ta n on e (18). To a stirred solution of alcohol 17 (1.7 g,
11.1 mmol), imidazole (1.28 g, 18.9 mmol), and a catalytic
amount of DMAP in DMF (12 mL) was added TBSCl (2.5 g,
16.6 mmol) at 0 °C, and stirring was continued for 1.5 h at rt.
The reaction mixture was diluted with Et2O and washed with
10% HCl and saturated aqueous NaHCO3 and NaCl. The
residue upon workup was chromatographed on silica gel with
hexane-AcOEt (98:2 v/v) as eluant to give silyl ether 18 (2.78
g, 94%) as a colorless oil: IR (neat) 1770, 1635 cm-1; 1H NMR
(300 MHz, CDCl3) δ 0.03 (3H, s), 0.05 (3H, s), 0.88 (9H, s),
1.45-2.27 (6H, m), 2.77-2.98 (2H, m), 3.52 and 3.75 (each 1H,
each d, J ) 9.5 Hz), 4.96 (1H, dd, J ) 1.5 and 10.3 Hz), 5.02
(1H, dd, J ) 1.5 and 17.2 Hz), 5.68-5.88 (1H, m); 13C NMR
(75 MHz, CDCl3) δ -5.5, 18.3, 19.3, 25.9, 28.8, 30.9, 43.9, 65.0,
70.1, 114.9, 138.1, 214.8; MS m/ z 268 (M+). Anal. Calcd for
C15H28O2Si: C, 67.11; H, 10.51. Found: C, 66.88; H, 10.57.
Gen er a l P r oced u r e for th e P r ep a r a tion of Isop r op en -
ylcyclobu ta n ol Der iva tives. P r ep a r a tion of (1R,2S)-2-
[4-(ter t-Bu tyld ip h en ylsiloxy)bu tyl]-1-isop r op en ylcyclo-
23: yield 19%; colorless oil; IR (neat) 3460, 1630 cm-1; H
NMR (500 MHz, CDCl3) δ 0.09 (3H, s), 0.10 (3H, s), 0.91 (9H,
s), 1.34-1.46 (2H, m), 1.50-1.57 (1H, m), 1.57-1.67 (1H, m),
1.76 (3H, s), 1.78-1.90 (2H, m), 1.92-2.02 (1H, m), 2.35-2.44
(1H, m), 3.68 and 3.93 (each 1H, each d, J ) 10.4 Hz), 4.07
(1H, s), 4.85-5.01 (4H, m), 5.69-5.80 (1H, m); 13C NMR (125
MHz, CDCl3) δ -5.6, -5.5, 18.1, 19.9, 21.2, 25.8, 28.4, 30.0,
31.2, 50.5, 65.5, 82.0, 111.3, 114.2, 139.1, 146.9; MS m/ z 253
(M+ - 57). Anal. Calcd for C18H34O2Si: C, 69.62; H, 11.04.
Found: C, 69.79; H, 11.02.
(1R ,2S )-2-(4-H yd r oxyb u t yl)-1-isop r op e n ylcyclob u -
ta n ol (24). By following the same procedure described for 13,
24 was prepared: yield 95%; colorless needles; mp 52-53 °C
(from hexane-Et2O); IR (CHCl3) 3450, 1640 cm-1 1H NMR
;
(500 MHz, CDCl3) δ 1.18-1.35 (2H, m), 1.36-1.47 (1H, m),
1.48-1.58 (3H, m), 1.58-1.63 (2H, m), 1.73 (3H, s), 1.74-1.89
(2H, m), 1.95-2.07 (2H, m), 2.07-2.20 (1H, m), 2.34-2.44 (1H,
m), 3.51-3.67 (2H, m), 4.75 and 4.88 (each 1H, each d, each J
) 1.2 Hz); 13C NMR (125 MHz, CDCl3) δ 18.2, 21.4, 23.3, 29.3,
31.6, 32.8, 42.6, 62.6, 79.7, 109.2, 149.4; MS m/ z 184 (M+);
HRMS calcd for C11H20O2 184.1463 (M+), found 184.1466.
(1R,2S)-1-Isop r op en yl-2-[(E)-5-(m et h oxyca r b on yl)-4-
p en ten yl]cyclobu ta n ol (25). To a stirred solution of DMSO
(1.11 mL, 15.7 mmol) in CH2Cl2 (10 mL) was added (COCl)2
(1.14 mL, 13.1 mmol), and then the solution of alcohol 24 (480
mg, 2.61 mmol) in CH2Cl2 (5 mL) at -78 °C. After stirring