Notes
J ournal of Natural Products, 1999, Vol. 62, No. 4 627
were run on a Bruker AMX-400 MHz or a Gemini-300 MHz
instrument with TMS as internal standard and CDCl3 as
solvent. Optical rotation values were measured on a Perkin-
Elmer 241 polarimeter at 25 °C. EIMS spectra were obtained
on a Varian MAT-711 or HP-5989A spectrometer. HREIMS
were recorded on a Finnigan MAT spectrometer. Column
chromatography was performed on silica gel, 200-300 mesh,
from Qing Dao, China.
(2S,3S,4Z)-1-p-Meth oxyben zyloxy-2,3-isop r op ylid en e-
d ioxyd od eca -4-en e (6). Dimethyl sulfoxide (4.70 mL, 65.88
mmol), dissolved in CH2Cl2 (10 mL), was added to a solution
of oxalyl chloride (2.90 mL, 32.94 mmol) in CH2Cl2 (50 mL) at
-78 °C. After 15 min, a solution of 5 (6.20 g, 21.96 mmol) in
CH2Cl2 (10 mL) was added and the mixture stirred for 30 min.
Triethylamine (15 mL, 110 mmol) in CH2Cl2 (10 mL) was
added, and the resulting mixture was stirred for another 10
min and then allowed to warm to room temperature. The
resulting mixture was poured into H2O and extracted with
CH2Cl2. The extract was washed with 1% HCl, H2O, and
saturated NaCl, dried (MgSO4), and concentrated to give the
corresponding aldehyde, which was directly used for the next
reaction.
To a solution of octyltriphenylphosphonium bromide (12.00
g, 26.35 mmol) in THF (150 mL) was added potassium tert-
butoxide (26 mL, 1 M in THF, 26 mmol) at room temperature.
After being stirred for 1 h, the mixture was cooled to -78 °C.
To this mixture was added a solution of the above aldehyde
in THF (20 mL), and the whole mixture was stirred for another
2 h. Stirring was continued overnight at room temperature.
The mixture was quenched with saturated aqueous NH4Cl and
extracted with ether. The extract was washed with saturated
NaCl, dried (MgSO4), and concentrated. Column chromatog-
raphy of the residue (petroleum ether/ethyl acetate, 20:1) gave
the desired Z-isomer 6 (5.14 g, 64.6% from 5) as a colorless
1H NMR (CDCl3, 300 MHz) δ 5.72 (dt, 1H, J ) 10.8, 7.6 Hz,
H-5), 5.37 (dd, 1H, J ) 10.8, 9.1 Hz, H-4), 4.69 (m, 1H, H-3),
3.88 (X of ABX, 1H, H-2), 3.61 (AB of ABX, 2H, J AB ) 4.3 Hz,
J AX ) J BX ) 11.9 Hz, H-1), 2.12 (m, 2H, H-6), 1.45 and 1.46 (s,
2 × 3H, C(CH3)2), 1.36 (m, 2H, H-7), 1.28 (m, 8H, H-8 f H-11),
0.87 (t, 3H, J ) 6.7 Hz, H-12); EIMS m/z 274 [M+], 259, 239,
196, 181, 97, 85(100); anal. C 65.52%, H 9.93%, calcd for
C15H27ClO2, C 65.55%, H 9.90%.
(3S,4Z)-Dod ec-4-en -1-yn -3-ol (9). n-Butyllithium (22 mL,
2.15 M in hexane, 46.92 mmol) was added to a solution of
diisopropylamine (6.60 mL, 46.92 mmol) in THF (80 mL) at 0
°C. After being stirred for 30 min, the mixture was cooled to
-78 °C. To this mixture was added a solution of 8 (2.15 g,
7.82 mmol) in THF (20 mL). Stirring was continued for 4 h,
and the reaction was then warmed to room temperature and
stirred overnight. The mixture was quenched with saturated
aqueous NH4Cl and extracted with ether. The extract was
washed with saturated NaCl, dried (MgSO4), and concentrated.
Column chromatography of the residue (petroleum ether/ethyl
acetate, 20:1) gave 9 as a colorless oil (820 mg), and 200 mg of
8 was recovered (64.1%): [R]D ) 122.9° (c 1.0, CHCl3); IR (film)
ν
max 3311, 2960, 2930, 2860, 2117, 1660, 1466, 1018, 654 cm-1
;
1H NMR (CDCl3 300 MHz) δ 5.56 (m, 2H, H-4, H-5), 5.13 (dd,
1H, J ) 2.2 Hz, 7.3 Hz, H-3), 2.49 (d, 1H, J ) 2.2 Hz, H-1),
2.11 (m, 2H, H-6), 1.36 (m, 2H, H-7), 1.27 (m, 8H, H-8 f H-11),
0.86 (t, 3H, 6.7 Hz, H-12); EIMS m/z 179 [M+ - 1], 162, 151,
137, 109, 95, 81 (100), 68, 55; HREIMS m/z 179.1448 (calcd
for C12H19O, 179.1437).
(3S,4Z)-1-Br om od od ec-4-en -1-yn -3-ol (2). N-Bromosuc-
cinimide (760 mg, 4.24 mmol) and AgNO3 (100 mg, 0.57 mmol)
were added to a solution of 9 (510 mg, 2.83 mmol) in acetone
(20 mL) at room temperature. After being stirred for 3 h, the
mixture was poured into saturated aqueous Na2SO3 and
extracted with ether. The extract was washed with saturated
NaCl, dried (MgSO4), and concentrated. Column chromatog-
raphy of the residue (petroleum ether/ethyl acetate, 50:1) gave
2 (580 mg, 79.1%) as a colorless oil: [R]D ) 77.4° (c 0.90,
CHCl3); IR (film) νmax 3427, 2960, 2930, 2860, 2187, 1726, 1645,
oil: [R] ) -8.7° (c 1.05, CHCl3); IR (film) νmax 3320, 2990,
D
2960, 2930, 2860, 1710, 1612, 1460, 1350, 1514, 1250, 1063,
1
822 m-1; H NMR (CDCl3, 400 MHz) δ 7.23 (d, 2H, J ) 8.5
Hz, Ph), 6.85 (d, 2H, J ) 8.5 Hz, Ph), 5.63 (dt, 1H, J ) 10.8,
7.6 Hz, H-5), 5.35 (dd, 1H, J ) 10.8, 9.1 Hz, H-4), 4.59 (m, 1H,
H-3), 4.51 (s, 2H, PhCH2O), 3.82 (m, 1H, H-2), 3.79 (s, 3H,
CH3O), 3.51 (m, 2H, H-1), 2.03 (m, 2H, H-6), 1.41 (s, 2 × 3H,
C(CH3)2), 1.30 (m, 2H, H-7), 1.22 (m, 8H, H-8 f H-11), 0.87
(t, 3H, J ) 6.7 Hz, H-12); EIMS m/z 376 [M+], 361, 318, 272,
210, 121 (100), 97, 77, 59; anal. C 73.09%, H 9.65%, calcd for
1626, 1466, 1248, 980, 740, 660 cm-1 1H NMR (CDCl3, 300
;
MHz) δ 5.54 (m, 2H, H-4, H-5), 5.15 (d, 1H, J ) 7.3 Hz, H-3),
2.10 (m, 2H, H-6), 1.36 (m, 2H, H-7), 1.27 (m, 8H, H-8 f H-11),
0.89 (t, 3H, J ) 6.7 Hz, H-12); EIMS m/z 257/259 [M+ - 1],
242, 161 (100), 146, 133, 109, 95, 81, 67, 55; HREIMS m/z
257.0545 (calcd for C12H18BrO, 257.0542).
(3R,8S)-3-(ter t-Bu tyld ip h en ylsilyoxy)fa lca r in d iol (10).
To a solution of CuCl (4 mg, 0.038 mmol), NH2OH‚HCl (16
mg, 0.225 mmol), 65% EtNH2 (0.8 mL) in MeOH (1 mL) at 0
°C were added successively 3 (240 mg, 0.75 mmol) and 2 (176
mg, 0.68 mmol) in MeOH (1 mL). After being stirred for 30
min, the mixture was treated with H2O and extracted with
ether. The extract was washed with saturated NaCl, dried
(MgSO4), and concentrated. Column chromatography of the
residue (petroleum ether/ethyl acetate, 20:1) gave 10 (218 mg,
64.3%) as a slightly yellow oil: [R]D ) 108.8° (c 1.0, CHCl3);
IR (film) νmax 3311, 2960, 2930, 2860, 2150, 1970, 1860, 1464,
1427, 1112, 821, 702 cm-1; 1H NMR (CDCl3, 300 MHz) δ 7.69
(m, 4H, SiPh), 7.39 (m, 6H, SiPh), 5.83 (ddd, 1H, J ) 17.0,
10.1, 5.4 Hz, H-2), 5.56 (m, 2H, H-9, H-10), 5.27 (dt, 1H, J )
17.0, 1.3 Hz, H-1a), 5.18 (d, J ) 8.1 Hz, H-8), 5.12 (dt, 1H, J
) 10.1, 1.3 Hz, H-1b), 4.83 (br d, J ) 5.4 Hz, H-3), 2.10 (m,
2H, H-11), 1.38 (m, 2H, H-12), 1.30 (m, 8H, H-13 f H-16),
1.10 (s, 9H, SiC(CH3)3), 0.89 (t, 3H, J ) 6.7 Hz, H-17); EIMS
m/z 441 [M+ - C(CH3)], 384, 286, 231 (100), 199, 83, 55, 43;
HREIMS m/z 498.2926 (calcd for C33H42SiO2, 498.2956).
F a lca r in d iol (1). TBAF (0.6 mL, 1 M in THF, 0.60 mmol)
was added to a solution of 10 (60 mg, 0.12 mmol) in THF (5
mL) at 0 °C. After being stirred for 3 h, the mixture was
treated with saturated aqueous NH4Cl and extracted with
ethyl acetate. The extract was washed with saturated NaCl,
dried (MgSO4), and concentrated. Column chromatography of
the residue (petroleum ether/ethyl acetate, 5:1) gave 1 (26 mg,
83.9%) as a slightly yellow oil: [R]D ) 211.7° (c 0.65, CHCl3)
[lit.14 [R]D ) 219.4° (c 4.6, CHCl3)]; IR (film) νmax 3338, 2960,
2930, 2860, 2231, 2150, 1709, 1464, 1263, 1119, 1018, 933
C
23H36O4, C 73.37%, H 9.64%.
(2S,3S,4Z)-2,3-Isopr opyliden edioxydodeca-4-en -1-ol (7).
To a stirred solution of 6 (1.90 g, 5.24 mmol) in CH2Cl2 (25
mL) and H2O (1.25 mL, 1/20 of CH2Cl2) was added DDQ (1.78
g, 7.86 mmol). After the solution was stirred for 2 h, saturated
aqueous NaHCO3 was added, and the mixture was extracted
with CH2Cl2. The extract was washed with saturated aqueous
NaHCO3 and NaCl, dried (MgSO4), and concentrated. Column
chromatography of the residue (petroleum ether/ethyl acetate,
50:1 f 20:1) gave 7 (1.09 g, 81.3%) as a colorless oil: [R]D
)
-8.6° (c 0.95, CHCl3); IR (film) νmax 3450, 2990, 2930, 2860,
1650, 1512, 1379, 1236, 1057, 856 cm-1; 1H NMR (CDCl3, 300
MHz) δ 5.69 (dt, 1H, J ) 10.8, 7.6 Hz, H-5), 5.37 (dd, 1H, J )
10.8, 9.1 Hz, H-4), 4.69 (m, 1H, H-3), 3.71 (X of ABX, 1H, H-2),
3.54 and 3.81 (AB of ABX, 2H, J AB ) 3.3 Hz, J AX ) J BX ) 12.0
Hz, H-1), 2.10 (m, 2H, H-6), 1.42 (s, 2 × 3H, C(CH3)2), 1,34
(m, 2H, H-7), 1.26 (m, 8H, H-8 f H-11), 0.88 (t, 3H, J ) 6.7
Hz, H-12); EIMS m/z 256 [M+], 241, 196, 181, 155, 124 (100),
109, 97, 81, 59, 55; anal. C 70.53%, H 11.05%, calcd for
C
15H28O3, C 70.27%, H 11.01%.
(2R,3S,4Z)-1-Ch lor o-2,3-isop r op ylid en ed ioxyd od eca -4-
en e (8). To a solution of 7 (2.31 g, 9.01 mmol) in CCl4 (40 mL)
was added triphenylphosphine (4.73 g, 18.02 mmol) and the
mixture refluxed for 12 h. The reaction mixture was cooled to
room temperature, poured into petroleum ether (200 mL), and
left at 0 °C overnight. The mixture was filtered and concen-
trated, and column chromatography of the residue (petroleum
ether/ethyl acetate 100:1) gave 8 (2.25 g, 91.1%) as a colorless
oil: [R]D ) -9.6° (c 1.15, CHCl3); IR (film) νmax 2990, 2960,
2930, 2860, 1760, 1680, 1458, 1373, 1223, 1061, 899, 748 cm-1
;
cm-1; H NMR (CDCl3, 300 MHz) δ 5.93 (ddd, 1H, J ) 17.0,
1