Isopropyl 1,2,3,4,4a,9,10,10a-octahydro-6-methoxy-1,1,4a-
trimethylphenanthrene-9-carboxylate 6c and 7c
6.71 (1H, dd, J 2.7, 8.6), 3.87 (1H, br d, J 7.3), 3.78 (3H, s), 2.22
(2H, br d, J 13.8), 2.05–1.89 (1H, m), 1.77–1.22 (6H, m), 1.17
(3H, s), 0.95 (3H, s), 0.91 (3H, s); δC 181.5, 158.6, 151.8, 131.2,
122.7, 110.9, 110.4, 55.2, 46.6, 44.1, 41.1, 38.4, 38.1, 33.2, 30.0,
24.8, 22.4, 21.6, 19.3.
Isopropyl 2-(4-methoxyphenyl)-5,9-dimethyldeca-4,8-dienoate
4c (244 mg, 0.71 mmol) as a solution in nitromethane (2 ml) was
added to a nitromethane (10 ml) solution of BF3ؒOEt2 (0.37 ml,
2.98 mmol) at ambient temperature and the solution was stirred
for 4 h at ambient temperature. The reaction was stopped by
addition of saturated aq. NaHCO3 and the mixture was
extracted with EtOAc. The solution was washed with brine,
dried over MgSO4, and evaporated. The residue was chromato-
graphed on a silica gel column with EtOAc–hexane (1:10) to
give a mixture (10:1) of phenanthrenes 6c and 7c (159 mg,
65.2%) as a liquid (Found: Mϩ, 344.2365. C22H32O3 requires M,
344.2351); m/z 344 (Mϩ, 22%), 257 (100), 201 (14), 187 (12), 173
(23), 161 (11), 129 (15); λmax(EtOH)/nm 202 (ε/dm3 molϪ1 cmϪ1
4.8 × 103), 277 (3.3 × 102); νmax(film)/cmϪ1 2937, 1734, 1608,
1577, 1504, 1468, 1373, 1294, 1257, 1174, 1105, 1074, 1043, 864,
848, 808; δH 7.09 (1H, d, J 8.6), 6.82 (1H, d, J 2.1), 6.69 (1H, dd,
J 2.6, 8.4), 5.01 (1H, septet, J 6.3), 3.79 (1H, d, J 7.3), 3.77 (3H,
s), 2.25–1.27 (9H, m), 1.24 (6H, m), 1.18 (3H, s), 0.97 (3H, s),
0.92 (3H, s); δC 174.6, 158.4, 151.8, 130.9, 123.7, 110.8, 110.2,
67.9, 55.2, 46.3, 44.3, 41.5, 38.5, 38.1, 33.3, 33.1, 24.8, 22.6,
22.0, 21.9, 21.6, 19.4.
1,2,3,4,4a,10a-Hexahydro-6-methoxy-1,1,4a-trimethyl-
phenanthrene 9
Lead() acetate (643 mg, 1.45 mmol) and copper() acetate
(116 mg, 0.57 mmol) were added to a solution of 1,2,3,4,4a,
9,10,10a-octahydro-6-methoxy-1,1,4a-trimethylphenanthrene-
9-carboxylic acid 8 (175 mg, 0.58 mmol) in pyridine (10 ml) and
the mixture was heated at 150 ЊC for 6 h under Ar. The mixture
was extracted with EtOAc and water, and the organic layer was
washed with brine, dried over MgSO4, and evaporated. The
residue was chromatographed on a silica gel with EtOAc–
hexane (1:10) to give an oily liquid, 1,2,3,4,4a,10a-hexahydro-6-
methoxy-1,1,4a-trimethylphenanthrene 9 (61 mg, 42%) (Found:
Mϩ, 256.1823, C18H24O requires M, 256.1827); m/z 256 (Mϩ,
73%), 255 (38), 185 (40), 174 (41), 149 (77), 137 (100), 121 (54),
95 (66); λmax(EtOH)/nm 210 (ε/dm3 molϪ1 cmϪ1 8.5 × 103), 272
(5.6 × 103); νmax(film)/cmϪ1 2931, 1736, 1604, 1568, 1485, 1395,
1306, 1279, 1246, 1213, 1174, 1076, 1037, 820; δH 6.98 (1H, d,
J 8.4), 6.75 (1H, d, J 2.5), 6.65 (1H, dd, J 2.5, 8.4), 6.49 (1H, dd,
J 3.1, 9.5), 5.88 (1H, dd, J 2.6, 9.5), 3.79 (3H, s), 2.1 (2H, m),
1.81–1.17 (5H, m), 1.04 (3H, s), 1.03 (3H, s), 0.97 (3H, s); δC
159.1, 150.1, 127.7, 127.3, 126.9, 126.2, 109.6, 108.9, 55.3, 50.9,
41.1, 38.2, 36.0, 33.0, 32.7, 22.7, 20.3, 19.1.
Methyl ester pair 6b, 7b and menthyl ester 6d were syn-
thesized by similar procedures to that described above.
Methyl 1,2,3,4,4a,9,10,10a-octahydro-6-methoxy-1,1,4a-tri-
methylphenanthrene-9-carboxylate 6b and 7b (mixture). A liquid
(Found: Mϩ, 316.2021. C20H28O3 requires M, 316.2038); m/z
316 (Mϩ, 44%), 273 (23), 257 (59), 192 (44), 180 (100), 179
(100), 151 (100), 135 (63), 121 (57), 69 (53); λmax(EtOH)/nm 227
(ε/dm3 molϪ1 cmϪ1 2.0 × 103), 275 (1.3 × 103), 282 (1.2 × 103);
νmax(film)/cmϪ1 2948, 1737, 1610, 1573, 1255, 1160, 1039, 848;
δH 7.11 (1H, d, J 8.3), 6.83 (1H, d, J 2.4), 6.69 (1H, dd, J 2.4, 8.4),
3.85 (1H, d, J 7.3), 3.77 (3H, s), 3.68 (3H, s), 2.19 (2H, m), 1.90
(1H, m), 1.8–1.2 (6H, m), 1.17 (3H, s), 0.95 (3H, s), 0.91 (3H, s);
δC 175.3, 158.4, 151.6, 130.8, 123.2, 110.7, 110.2, 54.8, 51.8,
46.4, 44.0, 41.3, 38.4, 38.0, 33.1, 32.8, 24.7, 22.5, 21.5, 19.2.
1,2,3,4,4a,9,10,10a-Octahydro-6-methoxy-1,1,4a-trimethyl-
phenanthrene 10
A mixture of 1,2,3,4,4a,10a-hexahydro-6-methoxy-1,1,4a-tri-
methylphenanthrene 9 (5.0 mg, 0.02 mmol) and 5% Pd/C (1 mg)
in EtOAc (3 ml) was stirred under H2 at ambient temperature for
16 h. The mixture was filtered and the filtrate was evaporated.
The residue was chromatographed on a silica gel column with
EtOAc–hexane (1:10) to give 1,2,3,4,4a,9,10,10a-octahydro-6-
methoxy-1,1,4a-trimethylphenanthrene 10 (4.3 mg, 85%), a
liquid (Found: Mϩ, 258.1975. C18H26O requires M, 258.1984);
m/z 258 (Mϩ, 100%), 243 (48), 187 (19), 173 (38), 161 (58), 147
(47), 121 (18); λmax(EtOH)/nm 202 (ε/dm3 molϪ1 cmϪ1 3.8 ×
103), 280 (3.6 × 102), 282 (1.2 × 103); νmax(film)/cmϪ1 2941, 2908,
1736, 1610, 1577, 1502, 1458, 1288, 1252, 1174, 1070, 1043, 804;
δH 6.95 (1H, d, J 8.4), 6.80 (1H, d, J 2.5), 6.65 (1H, dd, J 2.5,
8.3), 3.77 (3H, s), 2.90–2.73 (2H, m), 2.24 (1H, d, J 12.4), 1.88–
1.20 (8H, m), 1.19 (3H, s), 0.94 (3H, s), 0.92 (3H, s); δC 157.5,
151.3, 129.7, 127.4, 110.6, 110.1, 55.3, 50.4, 41.7, 38.9, 38.1,
33.6, 33.4, 29.7, 24.9, 21.8, 19.4, 19.2.
Menthyl 1,2,3,4,4a,9,10,10a-octahydro-6-methoxy-1,1,4a-tri-
methylphenanthrene-9-carboxylate 6d, diastereomeric mixture.
A liquid, m/z 440 (Mϩ, 55%), 397 (23), 257 (100), 201 (22), 173
(46), 161 (57), 83 (27), 69 (23), 55 (23); νmax(film)/cmϪ1 2952,
2877, 1718, 1610, 1457, 1255, 1164, 1037; δH 7.07 (1H, m), 6.82
(1H, m), 6.68 (1H, m), 4.62 (1H, m), 3.83 (1H, d, J 7.3), 3.77
(3H, s), 2.2–1.1 (16H, m), 0.95, 0.65 (20H, m).
1,2,3,4,4a,9,10,10a-Octahydro-6-methoxy-1,1,4a-trimethyl-
phenanthrene-9-carboxylic acid 8 and 6a
A mixture of isopropyl 1,2,3,4,4a,9,10,10a-octahydro-6-meth-
oxy-1,1,4a-trimethylphenanthrene-9-carboxylate 6c and 7c (563
mg, 1.64 mmol) and KOH (920 mg) in EtOH (10 ml) and water
(10 ml) was heated under reflux for 10 h. After cooling, the
mixture was acidified with 6 M HCl and extracted with EtOAc.
The organic layer was washed with brine, dried over MgSO4
and evaporated to give a mixture (8:6a, 1:10) (470 mg, 95%)
which was chromatographed on silica gel with EtOAc–hexane
(1:10) to give 1,2,3,4,4a,9,10,10a-octahydro-6-methoxy-1,1,4a-
trimethylphenanthrene-9-carboxylic acid 8 and C-9 epimer 6a.
Acid 8, mp 175.8 ЊC (Found: Mϩ, 302.1876, C19H26O3
requires M, 302.1882); m/z 302 (Mϩ, 77%), 257 (100), 201 (19),
187 (21), 173 (40), 161 (48), 149 (27); νmax(film)/cmϪ1 2941,
1699, 1610, 1574, 1502, 1464, 1404, 1284, 1252, 1207, 1022, 935;
δH 7.13 (1H, d, J 8.7), 6.83 (1H, d, J 2.8), 6.70 (1H, dd, J 2.8,
8.7), 3.91 (1H, dd, J 8.4, 10.9), 3.78 (3H, s), 2.28–1.30 (9H, m),
1.27 (3H, s), 0.96 (3H, s), 0.95 (3H, s); δC 181.8, 158.5, 151.9,
129.5, 123.2, 111.0, 110.3, 55.2, 48.8, 46.1, 41.6, 38.8, 37.9, 33.6,
33.2, 24.8, 23.5, 21.6, 19.2.
7-Acetyl-1,2,3,4,4a,9,10,10a-octahydro-6-methoxy-1,1,4a-
trimethylphenanethrene 11
A mixture of AlCl3 (133 mg, 1 mmol) and CH3COCl (0.07 ml,
0.96 mmol) in dry CH2Cl2 (5 ml) was stirred at ambient tem-
perature for 30 min under Ar, and then a CH2Cl2 (2 ml) solution
of 1,2,3,4,4a,9,10,10a-octahydro-6-methoxy-1,1,4a-trimethyl-
phenanthrene 10 (98 mg, 0.38 mmol) was added to the mixture.
After stirring of the mixture at ambient temperature for 1.5 h,
the reaction was stopped with water and the mixture was
extracted with EtOAc. The organic layer was washed with brine,
dried over MgSO4, and evaporated. The residue was chromato-
graphed on a silica gel column with EtOAc–hexane (1:5) to
give 7-acetyl-1,2,3,4,4a,9,10,10a-octahydro-6-methoxy-1,1,4a-
trimethylphenanthrene 11 (100 mg, 87%), a liquid (Found: Mϩ,
300.2104, C20H28O2 requires M, 300.2089); m/z 300 (Mϩ, 100%),
285 (76), 217 (30), 203 (38), 189 (30), 149 (37), 137 (15);
λmax(EtOH)/nm 218 (ε/dm3 molϪ1 cmϪ1 1.9 × 103), 258 (1.0 ×
103), 320 (3.8 × 102); νmax(film)/cmϪ1 2941, 1676, 1496, 1464,
1404, 1354, 1267, 1207, 1180, 1037; δH 7.44 (1H, s), 6.83 (1H, s),
3.87 (3H, s), 2.87 (2H, m), 2.58 (3H, s), 2.26 (1H, br d, J 12.7),
Acid 6a, mp 144–145 ЊC, νmax(film)/cmϪ1 6102, 1714, 1608,
1573, 1186, 1072, 798; δH 713 (1H, d, J 8.6), 6.82 (1H, d, J 2.7),
J. Chem. Soc., Perkin Trans. 1, 2000, 2657–2664
2661