C.-C. Chang et al. / Phytochemistry 63 (2003) 825–833
831
Table 1;EIMS m/z 402 (18, M+), 386 (35), 371 (80),
315 (38), 293 (21), 152 (16), 151 (45), 135 (21), 85
ml) to destroy excessive sodium, and the organic solvent
was removed by condensation. The aqueous solution of
the residue (100 ml) was then adjusted to pH 7 by 1 N
HCl and partitioned against Et2O (100 ml ꢂ 3). The
combined Et2O layers after drying over Na2SO4 and
subsequent condensation gave a residue (137 mg), which
was applied onto a silica gel column [230–400 mesh, 6 g,
Me2CO–CHCl3–hexane (5: 47.5: 47.5)] to give 14 (86.7
(79), 83 (100);HREIMS:
C23H30O6 402.2018).
m/z 402.2030 (calc. for
3.5. Urinatetralin (2)
Liquid; Rf 0.49;[ ꢂ]2D5 +7.0ꢁ (c=1.0);IR ꢀmax 2900,
1610, 1500, 1485, 1440, 1380, 1300, 1240, 1190, 1120,
1040, 940, 900, 870, 800, 760 cmꢀ1;UV lmax (log ")
231.8 (4.11, sh), 287.0 (3.91) nm;CD ( c=2.60 ꢂ 10ꢀ5
M) (Á") 312 (0), 299 (+6.83), 282 (ꢀ1.96), 258 (+0.92),
246 (ꢀ1.27), 225 (+6.34), 213 (ꢀ4.59), 203 (+36.03);
1
mg, 66% yield). 14: Rf 0.32 [Me2CO-CHCl3 (1:19)], H
NMR (CDCl3) ꢁ 6.78 (2H, s, H-50 and H-60), 6.68 (1H,
brs, H-20), 6.30 (1H, d, J=2.4 Hz, H-6), 6.18 (1H, d,
J=2.4 Hz, H-4), 4.88 (s, ꢀ OH, D2O exchangeable),
4.06 (1H, d, J=9.0 Hz, H-70), 3.83 (3H, s, 5-OMe), 3.77
(3H, s) and 3.71 (3H, s) (30- and 40-OMe), 3.30 (3H, s)
and 3.29 (3H, s) (9- and 90-OMe);EI-MS (rel. int.%)
402 (38, [M]+), 339 (21), 325 (26), 85 (64), 83 (100).
1
for H and 13C NMR spectroscopic data, see Table 1;
EIMS m/z 384(12, M+), 352 (12), 307 (26), 185 (12), 135
(58), 85 (48), 83 (78), 45(100);HREIMS: m/z 384.1559
(calc. for C22H24O6 384.1545).
3.8.2. Preparation of tetrazolyl derivative 15
3.6. Dextrobursehernin (3)
The mixture of 14 (53.2 mg, 0.132 mM), 5-chloro-1-
phenyltetrazole (48 mg, 0.267 mM), dry THF (5.5 ml)
and K2CO3 (39 mg, 0.283 mM) in a 10-ml round bot-
tom flask was stirred and refluxed under nitrogen over-
night (Mcdoniel and Cole, 1972). After cooling, the
solution was washed with H2O, dried over anhyd.
MgSO4 and condensed to give a residue (48 mg), which
was purified through a silica gel column [230–400 mesh,
5 g, Me2CO–CHCl3–hexane (1:18:2)] to afford 15 (43.7
mg, 82.1% yield). 15: 1H NMR (CDCl3) ꢁ 7.44-7.38
(5H, m, Tz-Ph), 6.69 (1H, d, J=2.4 Hz) and 6.65 (1H, d,
J=2.4 Hz) (H-4 and H-6), 6.44 (1H, d, J=8.2 Hz,
H-50), 6.36 (1H, d, J=1.9 Hz, H-20), 6.32 (1H, dd,
J=8.2, 1.9 Hz, H-60), 4.11 (1H, d, J=8.0 Hz, H-70), 3.50
(3H, s, 5-OMe), 3.76 (3H, s) and 3.72 (3H, s) (30- and 40-
OMe), 3.26 (3H, s) and 3.21 (3H, s) (90- and 9-OMe);
EI-MS (rel. int.%) 546 (50, [M]+), 402 (37), 401 (32),
339 (25), 325 (27), 307 (42), 292 (30), 151 (22), 118 (100),
91 (56), 77 (36).
Colorless liquid; Rf 0.16;[ ꢂ]2D5 +36.0ꢁ (c=1.0);IR
ꢀmax 3020, 2930, 2850, 1740, 1540, 1520, 1450, 1250,
1220, 1040, 1030, 935, 760 cmꢀ1;UV lmax (log ") 225.2
(4.22, sh), 283.0 (3.90) nm;CD ( c=2.7 ꢂ 10ꢀ5 M) (Á")
297 (+0.80), 291 (+1.66), 282 (ꢀ0.69), 274 (+0.42),
265 (+0.15), 259 (+1.13), 254 (+0.78), 236 (+3.34), 227
(+3.77), 219 (+2.51), 213 (+2.18), 204 (+13.29);for H
and 13C NMR spectroscopic data, see Table 2;EIMS m/z
370 (26, M+), 234 (7), 208 (4), 151 (100), 135 (20).
1
3.7. Urinaligran (4)
Colorless liquid; Rf 0.36;[ ꢂ]2D5 +19.0ꢁ (c=1.0);IR
ꢀmax 2925, 2880, 1615, 1505, 1490, 1445, 1400, 1250,
1200, 1120, 1100, 1040, 940, 870, 810 cmꢀ1;UV lmax
(log ") 234.8 (4.01), 285.8 (3.89) nm;CD ( c=2.40 ꢂ
10ꢀ5 M) (Á") 299 (+0.02), 293 (+1.03), 288 (+0.21),
278 (+0.21), 273 (ꢀ0.48), 268 (ꢀ0.18), 260 (+0.63), 255
(+0.20), 248 (+0.39), 233 (+0.28), 227 (+1.80), 213
(ꢀ0.11), 205 (1.81), 200 (ꢀ3.41);for 1H and 13C NMR
spectroscopic data, see Table 2;EIMS m/z 400 (89,
M+), 255 (44), 250 (22), 208 (87), 192 (70), 173 (100),
149 (50), 135 (20) 115 (37);HREIMS: m/z 400.1508
(calc. for C22H24O7 400.1494).
3.8.3. Preparation of 4-demethoxyphyltetralin (16) by
hydrogenolysis of 15
The mixture of 15 (30 mg), HOAc (10 ml) and 10%
Pd/C (30 mg) in a high-pressure reactor after degassing
ꢁ
was introduced H2 (75 psi) at 50 C. After 4 days’ reac-
tion, the reaction mixture was filtered through a Celite
cake. The Celite pad was exhaustively washed with
CHCl3. The combined CHCl3 washings and the filtrate
after drying over MgSO4 and subsequent condensation
gave a residue (26 mg), which was purified by silica gel
cc [230–400 mesh, 6 g, Me2CO–CHCl3–hexane (1:18:2)]
to afford 16 (14.4 mg, 48% yield). 16: Rf 0.58 [Me2CO–
CHCl3 (1:19)];[ ꢂ]D27 ꢀ22 (c=1.0);IR ꢀmax 2900, 2730,
1610, 1590, 1460, 1425, 1385, 1320, 1260, 1235, 1190,
3.8. Preparation of 4-demethoxyphyltetralin (16) from
hypophyllanthin (8) (Scheme 1)
3.8.1. Reaction of 8 with sodium in liquid ammonia
The solution of compound 8 (130.4 mg) dissolved in
dry THF (6.5 ml) was added to a dark blue solution of
sodium (350 mg)/ liquid ammonia (70 ml) dropwise with
vigorous stꢁirring under nitrogen in a dry ice-acetone
bath (ꢀ70 C) (Ram and Neumeyer, 1981). After 2 h,
ammonia was evaporated in a well-ventilated hood at
room temp. To the residue was slowly added MeOH (16
1160, 1140, 1120, 1030, 960, 895, 860, 810, 760 cmꢀ1
;
UV lmax (log ") 228.2 (4.23, sh), 280.8 (3.74);CD
(c=2.59 ꢂ 10ꢀ5 M) (Á") 298 (0), 288 (+4.18), 273
(ꢀ3.09), 247 (+2.24), 233 (ꢀ5.02), 221 (ꢀ2.88), 211