A. Sundaryono et al. / Journal of Molecular Structure 649 (2003) 177–190
179
2.2.1. Bis{2-hydroxy-3-methoxy-5-[7-(4-hydroxy-3-
methoxyphenyl)-hepta-1E,6E-diene-3,5-
dioxo]}methane (3)
the value 2–3. The mixture was stirred for 1 h
and extracted with dichloromethane. The organic
layer was washed with water, dried (Na2SO4) and
evaporated under vacuum. The solid residue was
purified by column chromatography (eluent dichlor-
omethane–diethyl ether 9:1). Compound 3 was
isolated as an orange solid (360 mg, 34%), mp
149–155 8C. HPLC analysis of the isolated com-
pound revealed only one absorption peak. FT-IR
(KBr) (cm21): 3490, 3380, 2930, 2850, 1630, 1594,
6-(4-Hydroxy-3-methoxyphenyl)-hex-5E-ene-2,4-
dione ( feruloylacetone, 5). Acetylacetone (7.5 g,
75 mmol), boric anhydride (3.5 g, 54 mmol) and tri-
n-butyl borate (23 g, 100 mmol) were mixed in ethyl
acetate (50 ml) at 0 8C with stirring. A solution of
vanillin (3.75 g, 25 mmol) and n-butylamine (0.5 ml)
in ethyl acetate was slowly added for 1.5 h. The
reaction mixture was stirred at 0 8C for 90 min and
then overnight at room temperature. Hydrochloric
acid (0.4N) was then added to the solution, at 60 8C,
until the pH became acid. The reaction mixture was
stirred for an additional hour and then extracted with
ethyl acetate. The organic layer was washed with
water, dried (Na2SO4) and evaporated under vacuum.
Feruloylacetone was obtained by column chromatog-
raphy (eluent dichloromethane–diethyl ether 95:5) as
a pale yellow solid (2.14 g, 37%), mp 144–147 8C (lit.
1
1510, 1385, 1290, 1150, 1080, 970, 830. H NMR
(400 MHz; DMF-d7) d: 3.90 (s, 6H, H700 and H7000),
3.92 (s, 6H, H7 and H70), 4.02 (s, 2H, H8), 6.02 (s,
2H, Hd and Hd0), 6.77 (d, J ¼ 15.5 Hz, 2H, Hb and
Hb0), 6.81 (d, J ¼ 15.5 Hz, 2H, Hf and Hf0), 6.90 (d,
J ¼ 7.8 Hz, 2H, H500 and H5000), 7.09 (d, J ¼ 2.1 Hz,
2H, H6 and H60), 7.19 (dd, J ¼ 2.1, 7.8 Hz, 2H, H600
and H6000), 7.33 (d, J ¼ 2.1 Hz, 2H, H2 and H20),
7.40 (d, J ¼ 2.1 Hz, 2H, H200 and H2000), 7.55 (d,
J ¼ 15.5 Hz, 2H, Ha and Ha0), 7.60 (d, J ¼ 15.5 Hz,
2H, Hg and Hg0), 9.73 (br s, 4H, phenol), 16.50 (br
s, enol). 13C NMR (100 MHz; DMF-d7) d: see
Table 1. The assignment was based on DEPT,
COSY, HMQC and HMBC experiments (see
Table 1). LSIMS-MS m/z 771 (6%, MNaþ), 330
(8), 749 (6%, MHþ), 329 (30), 177 (38), 176 (100);
m/z 749.2630 (Found MHþ); C43H41O12 requires
749.2598.
1
[24] 146–147 8C). H NMR (250 MHz; CDCl3) d:
2.20 (s, 3H, CH3–), 3.95 (s, 3H, CH3O–), 5.63 (s, 1H,
–CHyC–OH), 6.5 (d, 1H, –CHyCH–CyO), 7.0 (m,
3H, H–Ar), 7.6 (d, 1H, –CHyCH–Ar).
4,40-Dihydroxy-5,50-dimethoxy-3,30-methanediyl-
dibenzaldehyde (6). Vanillin (178 g, 1.17 mol) and an
aqueous solution (35%) of formaldehyde (60 g,
0.7 mol) were heated under reflux and stirring. A
solution of NaOH (50 g, 1.25 mol) in 50 ml of H2O
was added and the reaction mixture was refluxed for
3 h, then poured into 2.5 l of H2O at 75–80 8C before
a dilute hydrochloric acid (10%) solution (0.5 l) was
added dropwise. The solid was filtered, washed with
water and acetone and dried under vacuum. TLC
analysis indicated the presence of pure 6 (17 g, 10%),
mp 255–262 8C (lit. [25] 274 8C). 1H NMR
(250 MHz; CDCl3) d: 3.90 (s, 6H, CH3O–Ar); 4.0
(s, 2H, Ar–CH2–Ar); 7.3 (m, 4H, –Ar); 9.75 (s, 2H,
–CHO).
2.2.2. 7,20-Dimethoxy-5,22-di-[7-(4-hydroxy-3-
methoxyphenyl)-hepta-1E,6E-diene 3,5-dioxo]
{[9,12,15,18-tetraoxatricyclo[17.4.0.03,8]tricosa-1
(23),3(8),4,6,19,21-hexaene} (4)
7,20-Dimethoxy-5,22-diformyl[9,12,15,18-tetraox-
atricyclo[17.4.0.03,8]tricosa-1 (23),3(8),4,6,19,21-
hexaene (7). Compound 6 (1 g, 3.16 mmol), sodium
carbonate (1.34 g, 12.64 mmol) and 1,8-diiodo-3,6-
dioxaoctane (1.17 g, 5.4 mmol) in DMF (150 ml)
were stirred at 100 8C, under a nitrogen atmosphere,
for 30 h. The solution was filtered then evaporated.
The solid residue was extracted with dichloro-
methane, washed by dilute hydrochloric acid and
water, dried (Na2SO4) and evaporated in vacuo. The
solid was purified by column chromatography (eluent
dichloromethane–diethyl ether 95:5) yielding the title
compound as a pale solid (650 mg, 48%), mp 171–
172 8C. FT-IR (KBr) (cm21): 3440, 2925, 2860, 2740,
1695, 1675, 1585, 1345, 1310, 1140, 1090, 1035, 745.
Curcuminoid 3. Feruloylacetone 5 (700 mg,
3.00 mmol), boric anhydride (294 mg, 4.20 mmol)
and tri-n-butyl borate (3.22 g, 14 mmol) were heated
at 80 8C, for 1 h, in DMF (30 ml). A solution of 6
(442 mg, 1.40 mmol) and n-butylamine (0.14 ml) in
DMF (5 ml) was slowly added, for 60 min, at the
same temperature. After 5 h, the reaction mixture
was cooled down to 60 8C and hydrochloric
acid (0.4N) was added until the pH reached