× 50 mL), and removal of the solvent followed by flash column
chromatography on silica gel with hexane/EtOAc (7:1) gave 5
(1.351 g, 74%) as a solid: mp 113-114 °C; H NMR (300 MHz,
18.1, 16.7; IR (neat) 3447, 2957, 1632, 1589, 1549, 1510, 1418,
1341, 1235, 1144, 1090 cm-1; EIMS m/z (%) 648 (M+, 2), 414
(23), 370 (16), 369 (20), 355 (11), 285 (13), 271 (10), 247 (32),
231 (55), 219 (12), 183 (55), 129 (13), 115 (100), 91 (10); HRMS
m/z (M+) calcd for C38H52O7Si 648.3482, found 648.3486.
Mallotophilippen C (1). To a solution of 9 (0.405 g, 0.62 mmol)
in ethanol (10 mL) was added HCl (5 drops) and the reaction
mixture was stirred at room temperature for 1 h. The reaction
mixture was diluted with saturated NaHCO3 solution (30 mL) and
extracted with EtOAc (3 × 30 mL). Removal of solvent and
purification by column chromatography on silica gel with hexane/
EtOAc (10:1) gave 1 (0.191 g, 65%) as an oil: 1H NMR (300 MHz,
CDCl3) δ 14.6, (1H, s), 8.00 (1H, d, J ) 15.6 Hz), 7.73 (1H, d, J
) 15.6 Hz), 7.48 (2H, d, J ) 8.6 Hz), 6.85 (2H, d, J ) 8.6 Hz),
6.57 (1H, d, J ) 9.9 Hz), 6.41 (1H, s), 5.61 (1H, s), 5.45 (1H, d,
J ) 9.9 Hz), 5.28 (1H, t, J ) 7.0 Hz), 5.03 (1H, t, J ) 6.8 Hz),
3.41 (2H, d, J ) 7.1 Hz), 2.17-2.09 (4H, m), 1.80 (3H, s), 1.67
(3H, s), 1.58 (3H, s), 1.51 (6H, s); 13C NMR (75 MHz, CDCl3) δ
193.0, 163.8, 157.7, 157.5, 154.7, 142.1, 140.3, 132.4, 130.2, 128.6,
125.5, 124.8, 123.5, 121.8, 116.8, 116.2, 106.2, 105.5, 102.4, 77.8,
39.8, 28.0, 26.3, 25.7, 21.7, 17.6, 16.1; IR (neat) 3450, 2975, 1605,
1537, 1452, 1350, 1263, 1166 cm-1; EIMS m/z (%) 474 (M+, 91),
460 (22), 459 (69), 405 (20), 391 (14), 389 (15), 352 (26), 351
(96), 339 (18), 335 (18), 323 (12), 286 (10), 285 (52), 269 (16),
243 (12), 232 (14), 232 (82), 230 (14), 229 (12), 216 (14), 215
(100), 189 (15), 183 (18), 149 (14), 147 (16), 135 (11), 115 (35),
69 (29); HRMS m/z (M+) calcd for C30H34O5 474.2406, found
474.2405.
1
CDCl3) δ 11.67 (1H, s), 9.70 (1H, s), 5.94 (1H, s), 5.20 (1H, t, J
) 7.0 Hz), 5.02 (1H, t, J ) 6.8 Hz), 3.27 (2H, d, J ) 7.0 Hz), 2.61
(3H, s), 2.20-1.84 (4H, m), 1.75 (3H, s), 1.62 (3H, s), 1.54 (3H,
s); 13C NMR (75 MHz, CDCl3) δ 203.7, 161.3, 140.1, 132.2, 123.5,
121.4, 105.4, 105.2, 95.3, 39.7, 32.8, 26.2, 25.7, 21.5, 17.7, 16.2;
IR (KBr) 3407, 2920, 1628, 1597, 1559, 1453, 1402, 1372, 1289
cm-1; EIMS m/z (%) 304 (M+, 38), 289 (3), 261 (9), 235 (25),
219 (22), 181 (100); HRMS m/z (M+) calcd for C18H24O4 304.1675,
found 304.1677.
Compound 6. To a solution of 5 (0.850 g, 2.79 mmol) and
3-methyl-2-butenal (0.469 g, 5.58 mmol) in CH2Cl2 (20 mL) was
added ethylenediamine diacetate (0.101 g, 0.58 mmol). The reaction
mixture was stirred at room temperature for 5 h. Evaporation of
solvent and purification by column chromatography on silica gel
with hexane/EtOAc (20:1) gave 6 (0.683 g, 66%) as a solid: mp
63-65 °C; 1H NMR (300 MHz, CDCl3) δ 14.1 (1H, s), 6.52 (1H,
d, J ) 9.9 Hz), 6.38 (1H, s), 5.40 (1H, d, J ) 9.9 Hz), 5.24 (1H,
t, J ) 7.0 Hz), 5.01 (1H, t, J ) 6.8 Hz), 3.37 (2H, d, J ) 7.0 Hz),
2.68 (3H, s), 2.15 (3H, s), 2.21-2.02 (4H, m), 1.79 (3H, s), 1.64
(3H, s), 1.58 (3H, s), 1.46 (6H, s); 13C NMR (75 MHz, CDCl3) δ
203.4, 162.9, 157.6, 155.3, 140.3, 132.3, 124.8, 123.5, 121.7, 116.6,
105.7, 105.2, 102.0, 77.7, 39.7, 33.2, 30.9, 27.9, 26.1, 25.7, 21.5,
17.7, 16.1; IR (KBr) 3297, 2971, 2924, 1645, 1607, 1564, 1466,
1427, 1381, 1317, 1256, 1200, 1175, 1132, 1094 cm-1; EIMS m/z
(%) 370 (M+, 58), 356 (13), 355 (52), 301 (35), 285 (24), 247
(42), 246 (15), 232 (15), 231 (100), 219 (10), 213 (16), 115 (14);
HRMS m/z (M+) calcd for C23H30O4 370.2144, found 370.2145.
Compound 7. Methoxymethyl chloride (0.121 g, 1.50 mmol)
was added to a solution of 6 (0.505 g, 1.36 mmol) and diisopro-
pylethylamine (0.879 g, 6.80 mmol) in dry CH2Cl2 (10 mL). The
reaction mixture was stirred at room temperature for 10 h and then
water (20 mL) was added. The reaction mixture was extracted with
CH2Cl2 (3 × 30 mL).The combined organic extracts were washed
with saturated NH4Cl solution (20 mL) and evaporated in vacuo.
Flash chromatography on silica gel with hexane/EtOAc (20:1)
Compound 10. A mixture of 4 (2.018 g, 12.0 mmol), prenyl
bromide (1.788 g, 12.0 mmol), and DBU (1.827 g, 12.0 mmol) in
dry THF (50 mL) was stirred at room temperature for 12 h. Addition
of 2 N HCl solution (50 mL), extraction with EtOAc (3 × 50 mL),
washing with brine (50 mL), and removal of the solvent followed
by flash column chromatography on silica gel with hexane/EtOAc
(5:1) gave 10 (1.134 g, 40%) as a solid: mp 166-167 °C; 1H NMR
(300 MHz, CDCl3) δ 5.82 (1H, s), 5.22 (1H, t, J ) 7.0 Hz), 3.33
(2H, d, J ) 7.1 Hz), 2.64 (3H, s), 1.80 (3H, s), 1.75 (3H, s); 13C
NMR (75 MHz, CDCl3) δ 203. 6, 163.5, 162.1, 160.5, 132.4, 122.9,
106.5, 104.9, 94.7, 32.8, 25.9, 21.4, 17.9; IR (KBr) 3418, 1634,
1402, 1370, 1285, 1235, 1150, 1073 cm-1; EIMS m/z (%) 236 (M+,
60), 221 (29), 193 (29), 181 (100), 165 (40), 153 (17), 69 (24);
HRMS m/z (M+) calcd for C13H16O4 236.1049, found 236.1050.
Compounds 11 and 12. To a solution of 10 (0.795 g, 3.36 mmol)
and citral (1.023 g, 6.72 mmol) in CH2Cl2 (20 mL) was added
ethylenediamine diacetate (0.121 g, 0.67 mmol). The reaction
mixture was stirred at room temperature for 8 h. Evaporation of
solvent and purification by column chromatography on silica gel
with hexane/EtOAc (20:1) gave 11 (0.971 g, 78%) and 12 (0.212
1
afforded 7 (0.530 g, 94%) as an oil: H NMR (300 MHz, CDCl3)
δ 13.72 (1H, s), 6.48 (1H, d, J ) 9.9 Hz), 5.44 (1H, d, J ) 9.9
Hz), 5.18 (1H, t, J ) 7.0 Hz), 5.02 (1H, t, J ) 6.8 Hz), 4.96 (2H,
s), 3.51 (3H, s), 3.27 (2H, d, J ) 6.2 Hz), 2.65 (3H, s), 2.01-1.95
(4H, m), 1.73 (3H, s), 1.69 (3H, s), 1.53 (3H, s), 1.45 (6H, s); 13
C
NMR (75 MHz, CDCl3) δ 204.6, 163.8, 158.5, 155.2, 135.6, 131.7,
126.2, 124.8, 123.1, 118.3, 115.5, 108.8, 107.1, 100.5, 58.3, 40.1,
34.0, 28.1, 27.0, 26.1, 22.9, 18.1, 16.6; IR (neat) 2930, 1616, 1424,
1364, 1287, 1161, 1134, 1049 cm-1; EIMS m/z (%) 414 (M+, 66),
399 (22), 370 (17), 369 (58), 367 (11), 313 (10), 291 (17), 285
(25), 271 (26), 259 (12), 247 (54), 246 (15), 245 (12), 232 (15),
231 (100), 217 (14), 213 (13), 69 (14); HRMS m/z (M+) calcd for
C25H34O5 414.2406, found 414.2408.
1
g, 17%). 11: H NMR (300 MHz, CDCl3) δ 14.1 (1H, s), 6.56
(1H, d, J ) 9.9 Hz), 6.30 (1H, s), 5.37 (1H, d, J ) 9.9 Hz), 5.24
(1H, t, J ) 7.1 Hz), 5.07 (1H, t. J ) 7.1 Hz), 3.36 (2H, d, J ) 7.2
Hz), 2.64 (3H, s), 2.17-2.03 (2H, m), 1.85-1.80 (2H, m), 1.81
(3H, s), 1.76 (3H, s), 1.64 (3H, s), 1.55 (3H, s), 1.41 (3H, s); 13C
NMR (75 MHz, CDCl3) δ 203.3, 162.9, 157.4, 155.5, 136.5, 132.1,
123.7, 123.4, 121.7, 117.0, 80.5, 41.5, 33.3, 26.5, 25.9, 25.6, 23.1,
21.5, 17.9, 17.6; IR (neat) 3349, 2930, 1615, 1429, 1372, 1294
cm-1; EIMS m/z (%) 370 (M+, 34), 355 (13), 315 (12), 303 (29),
288 (20), 287 (100), 285 (10), 247 (11), 235 (12), 232 (11), 231
(68), 219 (14), 213 (10); HRMS m/z (M+) calcd for C23H30O4
370.2144, found 370.2146. 12: 1H NMR (300 MHz, CDCl3) δ 13.55
(1H, s), 6.66 (1H, d, J ) 9.9 Hz), 5.39 (1H, d, J ) 9.9 Hz), 5.17
(1H, t, J ) 7.1 Hz), 5.06 (1H, t. J ) 7.1 Hz), 3.31 (2H, d, J ) 7.2
Hz), 2.63 (3H, s), 2.10-2.0 (2H, m), 1.82 (3H, s), 1.81-1.70 (2H,
m), 1.75 (3H, s), 1.63 (3H, s), 1.55 (3H, s), 1.36 (3H, s); 13C NMR
(75 MHz, CDCl3) δ 203.5, 159.3, 158.5, 157.4, 135.8, 131.8, 124.2,
123.8, 122.9, 121.5, 116.6, 105.0, 102.1, 80.3, 41.5, 33.0, 26.8,
25.8, 25.6, 22.6, 21.2, 17.8, 17.6; IR (neat) 2974, 1615, 1429, 1370,
1294 cm-1; EIMS m/z (%) 370 (M+, 45), 369 (10), 355 (22), 331
(10), 318 (21), 315 (21), 304 (13), 303 (62), 301 (13), 289 (10),
Compound 9. To a solution of 7 (0.450 g, 1.09 mmol) in ethanol
(10 mL) was added KOH (0.306 g, 5.45 mmol) and aldehyde 8
(0.331 g, 1.31 mmol). The reaction mixture was stirred at room
temperature for 48 h. Evaporation of ethanol, addition of 2 N HCl
(30 mL), extraction with EtOAc (3 × 50 mL), washing with brine
(30 mL), and removal of the solvent followed by flash column
chromatography on silica gel with hexane/EtOAc (20:1) gave 9
1
(0.538 g, 76%) as an oil: H NMR (300 MHz, CDCl3) δ 13.96
(1H, s), 7.97 (1H, d, J ) 15.6 Hz), 7.76 (1H, d, J ) 15.6 Hz), 7.53
(2H, d, J ) 8.8 Hz), 7.06 (2H, d, J ) 8.8 Hz), 6.52 (1H, d, J ) 9.9
Hz), 5.50 (1H, d, J ) 9.9 Hz), 5.49 (2H, s), 5.25 (2H, s), 5.20 (1H,
t, J ) 7.0 Hz), 5.04 (1H, t, J ) 6.8 Hz), 3.74 (2H, dd, J ) 8.4, 8.3
Hz), 3.57 (3H, s), 3.31 (2H, d, J ) 6.3 Hz), 2.06-1.97 (4H, m),
1.75 (3H, s), 1.62 (3H, s), 1.55 (3H, s) 1.52 (6H, s), 0.94 (2H, dd,
J ) 8.4, 8.3 Hz), -0.03 (9H, s); 13C NMR (75 MHz, CDCl3) δ
194.0, 164.0, 159.4, 158.4, 154.6, 142.8, 135.5, 132.2, 131.6, 130.3,
129.6, 126.0, 124.8, 123.3, 118.5, 117.0, 116.7, 115.8, 109.3, 107.4,
100.6, 94.6, 94.5, 78.0, 58.3, 56.7, 56.6, 40.1, 28.2, 27.1, 26.1, 23.1,
J. Org. Chem. Vol. 73, No. 11, 2008 4315