K. Krohn et al. / Phytochemistry 61 (2002) 931–936
935
OCH3), 6.42 (d, J=9.0Hz, 1H), 6.96 ( d, J=8.7 Hz,
2H), 7.50( d, J =15.4 Hz, 1H), 7.63 (d, J=8.7 Hz, 2H),
7.73 (d, J=9.0Hz, 1H), 7.88 ( d, J=15.4 Hz, 1H), 14.01
C-5), 115.9 (d, C-40), 128.3 (d, C-30), 129.4 (d, C-2, C-6),
131.0( d, C-70), 133.0( s, C-1), 158.2 (s, C-4), 159.7 (s,
C-80a), 159.8 (s, C-50), 204.0 (s, C=O).
(s, 1H, OH). 13C NMR (50MHz, CDCl ): d=16.8 (t),
3
27.2 (q), 32.3 (t), 55.8 (q), 76.2 (s), 109.5 (s, 109.7 (s),
113.3 (s), 114.8 (d), 118.5 (d), 128.1 (s), 128.9 (d), 130.7
(d), 144.1 (d), 161.1 (s), 162.1 (s), 164.5 (s), 192.3 (s).
3.4.1. 3-(3,4-Dimethoxyphenyl)-1-(5-hydroxy-2,2-
dimethyl-2H-chromen-6-yl)-propanone (16)
ꢁ
Mp: 120 C. IR (KBr) cmꢀ1: 3092, 2956, 2923, 1618,
1514 1291, 1259 1118, 1026. 1H NMR (200 MHz,
CDCl3): d=1.48 (s, 6H, 2ꢂCH3), 3.02 (m, 2H, 3-H),
3.23 (m, 2H, 2-H), 3.88 (s, 3H, OCH3), 3.90( s, 3H,
OCH3), 5.61 (d, J =10.1 Hz, 1H, 30-H), 6.34 (d, J=8.9
Hz, 1H, 80-H), 6.74 (d, J=10.1 Hz, 1H, 40-H), 6.79–6.81
(m, 3H, 2-H, 5-H, 6-H), 7.55 (d, J=8.9 Hz, 1H, 70-H),
13.08 (s, 1H, OH). 13C NMR (50MHz, CDCl 3):
d=28.4 (q, CH3), 30.2 (t, C-3), 49.9 (t, C-2), 55.95 (q,
OCH3), 56.04 (q, OCH3), 77.9 (s, C-20), 108.4 (d, C-80),
109.4 (s, C-40a), 111.4 (d, C-2), 111.9 (d, C-5), 113.5 (s,
C-60), 115.9 (d, C-40), 120.3 (d, C-6), 128.3 (d, C-30),
131.0( d, C-70), 133.6 (s, C-1), 147.6 (s, C-4), 149.0( s,
C-30), 159.7 (s, C-80a), 159.8 (s, C-50), 204.0 (s, C=O).
Elemental analysis: calcd for C22H24O5: C, 71.72%, H;
6.57%. Found: C, 71.34%; H, 6.60%.
3.3.7. 1-Iodomethyl-4-methoxybenzene (13) and 4-
Iodomethyl-1,2-dimethoxybenzene (14)
1-Iodomethyl-4-methoxybenzene (13) and 4-Iodo-
methyl-1,2-dimethoxybenzene (14) were prepared as
described in the literature (Stoner et al., 1995).
3.3.8. 1-Iodomethyl-4-methoxybenzene (13)
1H NMR (200 MHz, CDCl3): d=3.84 (s, 3H, OCH3),
4.52 (s, 2H, CH2), 6.86 (d, J=8.7 Hz, 2H, 3-H, 5-H),
7.36 (d, J=8.7 Hz, 2H, 2-H, 6-H). 13C NMR (50MHz,
CDCl3): d=7.1 (t, CH2), 55.8 (q, OCH3), 114.7 (d, C-3,
C-5), 130.5 (d, C-2, C-6), 131.8 (s, C-1), 159.6 (s, C-4).
3.3.9. 4-Iodomethyl-1,2-dimethoxybenzene (14)
1H NMR (200 MHz, CDCl3) d=3.90( s, 3H, OCH3),
3.92 (s, 3H, OCH3), 4.51 (s, 2H, CH2I), 6.80(d, J=8.2
Hz, 1H, 6-H), 6.93 (s, 1H, 3-H), 6.99 (d, J=8.2 Hz, 1H,
5-H). 13C NMR (50MHz, CDCl 3) d=7.6 (t, CH2), 56.3
(q, OCH3), 111.5 (d, C-3), 112.2 (d, C-6), 121.5 (d, C-5),
132.1 (s, C-4), 149.2 (s, C-1), 149.4 (s, C-2).
3.4.2. Crotaramosmin (17)
A solution of BBr3 in CH2Cl2 (1 mol/l, 1 ml, 1 mmol)
was added to a solution of 15 (135 mg, 0.4 mmol) in dry
CH2Cl2 (8 ml) at ꢀ40 ꢁC. The yellow solution was
ꢁ
allowed to warm up to 0 C and stirred for 3 h. HCl
solution (10%, 10 ml) was added, the organic phase was
separated, and the aqueous phase extracted with
CH2Cl2 (2ꢂ5 ml). The combined organic phases were
dried over MgSO4, filtered and evaporated. The crude
material was purified by preparative thin layer chroma-
tography using petroleum ether and ethyl acetate 7:3 as
eluant to yield 30mg (23%) of 17 identical with crotar-
3.4. Crotaramin (15)
A solution of LDA (2.2 equiv in 5 ml THF) was
added dropwise within 10min to a solution of 6-acetyl-
5-hydroxy-2,2-dimethyl-2H-chromene (4) (218 mg, 1
mmol) in THF at ꢀ30 ꢁC. The yellow solution was
stirred for 30min at ꢀ30 ꢁC and a solution of the
iodomethylbenzene 13 (496 mg, 2 mmol) in THF (5 ml)
was then added. The solution was stirred for 3 h at
1
amosmin (Kumar et al., 1999). H NMR (200 MHz,
CDCl3): d=1.49 (s, 6H, 2ꢂCH3), 3.01 (m, 2H, b-H),
3.21 (m, 2H, a-H), 5.62 (br s, 1H, 4-OH), 5.62 (d,
J=10.1 Hz, 1H, 30-H), 6.35 (d, J=8.9 Hz, 1H, 80-H),
6.76 (d, J=10.1 Hz, 1H, 40-H), 6.80( d, J=8.5 Hz, 2H,
3-H, 5-H), 7.13 (d, J=8.5 Hz, 2H, 2-H, 6-H), 7.56 (d,
J=8.9 Hz, 1H, 70-H), 13.08 (s, 1H, 50-OH). 13C NMR
ꢁ
ꢁ
ꢀ30 C and was then allowed to warm to 0 C. HCl
solution (10%, 10 ml) was added, the organic phase was
separated, and the aqueous phase extracted with ethyl
acetate (2ꢂ10ml). The combined organic phases were
washed with brine (10ml), dried over MgSO , filtered
(50MHz, CDCl ): d =28.4 (q, CH3), 29.8 (t, C-b), 40.0
4
3
and evaporated to dryness. The crude product was pur-
ified by column chromatography using petroleum ether
and ethyl acetate 9:1 as the eluant to ꢁyield 271 mg (80%)
(t, C-a), 77.9 (s, C-20), 108.5 (d, C-80), 109. 4 (s, C-40a),
113.5 (s, C-60), 115.5 (d, C-3, C-5), 115.9 (d, C-40), 128.4
(d, C-30), 129.6 (d, C-2, C-6), 131.0( d, C-70), 133.0( s,
C-1), 154.2 (s, C-4), 159.7 (s, C-80a), 159.8 (s, C-50),
204.2 (s, C=O).
1
of 15 as colorless crystals. mp: 48 C. H NMR (200
MHz, CDCl3) d=1.49 (s, 6H, 2ꢂCH3), 3.03 (m, 2H,
b-CH2), 3.22 (m, 2H, a- CH2), 3.83 (s, 3H, 4-OCH3),
5.62 (d, J=10.1 Hz, 1H, 30-H), 6.35 (d, J=9.0Hz, 1H,
80-H), 6.76 (d, J=10.1 Hz, 1H, 40-H), 6.88 (d, J=8.6 Hz,
2H, 3-H, 5-H), 7.19 (d, J=8.6 Hz, 2H, 2-H, 6-H), 7.56
3.4.3. Crotin (18)
A solution of BBr3 in CH2Cl2 (1 mol/l, 1.5 ml, 1.5
mmol) was added to a solution ꢁof 15 (147 mg 0.4 mmol)
in dry CH2Cl2 (8 ml) at ꢀ40 C. The yellow solution
(d, J=9.0Hz, 1H, 7 -H), 13.07 (s, 1H, 50-OH). 13C
0
ꢁ
NMR (50MHz, CDCl ) d=28.4 (q, 2ꢂCH3), 29.7 (t,
was allowed to warm to 0 C and was stirred for 3 h.
3
C-b), 40.0 (t, C-a), 55.4 (q, OCH3), 77.8 (s, C-20), 108.4
HCl solution (10%, 10 ml) was added, the organic
phase separated, and the aqueous phase extracted with
(d, C-80), 109. 4 (s, C-40a), 113.5 (s, C-60), 114.1 (d, C-3,