JOURNAL OF ASIAN NATURAL PRODUCTS RESEARCH
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3.2.14. Synthesis of 2-(3-benzyloxy-4-methoxyphenyl)ethan-1-ol (22)
A mixture of 21 (1.5 g, 5 mmol) and LiAlH4 (0.57 g, 15 mmol) was added to dry THF
(30 ml) under argon atmosphere at 0 ꢁC. The mixture was stirred for 3 h. After reac-
tion was completed (detected by TLC), 20 ml water was added to quench the reaction.
Then the mixture was extracted with EtOAc (50 ml ꢂ3). The organic phase was com-
bined and washed with brine, dried over Na2SO4, evaporated under vacuum to give
compound 22 (1.03 g, 80% yield) as an colorless solid, m.p.70–72 ꢁC. flit. [19] m.p.
80–80.5 ꢁCg. 1H NMR (600 MHz, CDCl3) d: 7.43 (d, J ¼ 7.5 Hz, 2H), 7.35 (t,
J ¼ 7.5 Hz, 2H), 7.30–7.29 (m, 1H), 6.84 (d, J ¼ 8.0 Hz, 1H), 6.77–6.76 (m, 2H), 5.14
(s, 2H), 3.86 (s, 3H), 3.76 (q, J ¼ 6.3 Hz, 2H), 2.74 (t, J ¼ 6.3 Hz, 2H); 13C NMR
(150 MHz, CDCl3) d: 148.5, 148.2, 137.2, 130.9, 128.6, 127.9, 127.5, 121.7, 115.2,
112.1, 71.1, 63.8, 56.2, 38.7.
3.2.15. Synthesis of (2R,3R,4S,5R,6R)-2-(acetoxymethyl)-6-[3-(benzyloxy)-4-methoxy-
phenethoxy]tetrahydro-2H-pyran-3,4,5-triyl triacetate (23)
Compound 23 was get with a similar approach to compound 8 (yield 90%), m.p.
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135–137 ꢁC, [a]20 ꢀ14.8 (c 0.7, CHCl3). H NMR (600 MHz, CDCl3) d: 7.44 (d,
D
J ¼ 7.4 Hz, 2H), 7.35 (t, J ¼ 7.4 Hz, 2H), 7.29 (d, J ¼ 7.4 Hz, 1H), 6.79 (d, J ¼ 8.0 Hz,
1H), 6.75–6.70 (m, 2H), 5.19–5.04 (m, 4H), 4.97 (dd, J ¼ 9.6, 8.0 Hz, 1H), 4.42 (d,
J ¼ 8.0 Hz, 1H), 4.25 (dd, J ¼ 12.3, 4.6 Hz, 1H), 4.11 (dd, J ¼ 12.2, 2.2 Hz, 1H), 4.04
(dt, J ¼ 9.4, 6.3 Hz, 1H), 3.84 (s, 3H), 3.65 (ddd, J ¼ 10.0, 4.6, 2.2 Hz, 1H), 3.56 (dt,
J ¼ 9.3, 7.4 Hz, 1H), 2.76 (t, J ¼ 6.5 Hz, 2H), 2.06 (s, 3H), 2.04 (s, 3H), 1.98 (s, 3H),
1.87 (s, 3H); 13C NMR (150 MHz, CDCl3) d: 170.8, 170.4, 169.5, 169.4, 148.3, 148.0,
137.3, 131.0, 128.6, 127.9, 127.5, 121.6, 115.2, 111.9, 100.9, 72.8, 71.9, 71.1, 71.0
(2 ꢂ C), 68.5, 62.0, 56.2, 35.5, 20.9, 20.7, 20.7, 20.6.
3.2.16. Synthesis of (2R,3R,4S,5R,6R)-2-(acetoxymethyl)-6-(3-hydroxy-4-methoxy-
phenethoxy)tetrahydro-2H-pyran-3,4,5-triyl triacetate (24)
A suspension of 23 (100 mg, 0.17 mmol) and palladium (20 mg, 10 wt.% on activated
carbon) in THF (3 ml) and CH3OH (30 ml) was stirred at room temperature under
hydrogen gas atmosphere for 24 h. After the reaction was completed, the mixture was
filtered through a pad of Celite. The filtrate was then concentrated in vacuo to get
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compound 24 (80 mg, 90%) as a colorless oil, [a]20 ꢀ28.8 (c 0.1, CHCl3). H NMR
D
(600 MHz, CDCl3) d: 6.75–6.73 (m, 2H), 6.64 (dd, J ¼ 8.1, 2.1 Hz, 1H), 5.16 (t,
J ¼ 9.5 Hz, 1H), 5.13–5.02 (m, 1H), 4.98 (dd, J ¼ 9.5, 8.0 Hz, 1H), 4.46 (d, J ¼ 8.0 Hz,
1H), 4.24 (dd, J ¼ 12.3, 4.7 Hz, 1H), 4.12 (dd, J ¼ 12.3, 2.4 Hz, 1H), 4.08–4.04 (m,
1H), 3.84 (s, 3H), 3.66 (ddd, J ¼ 10.0, 4.7, 2.4 Hz, 1H), 3.61 (dt, J ¼ 9.6, 7.3 Hz, 1H),
2.89–2.63 (m, 2H), 2.07 (s, 3H), 2.00 (s, 3H), 1.98 (s, 3H), 1.94 (s, 3H); 13C NMR
(150 MHz, CDCl3) d: 170.8, 170.4, 169.5, 169.5, 145.5, 145.2, 131.8, 120.5, 115.2,
110.7, 100.8, 72.9, 71.9, 71.2, 70.9, 68.5, 62.0, 56.0, 35.4, 20.8, 20.7, 20.7, 20.6.
3.2.17. Synthesis of (2R,3R,4S,5S,6R)-2-(3-hydroxy-4-methoxyphenethoxy)-6-
(hydroxymethyl)tetrahydro-2H-pyran-3,4,5-triol (4)
Compound 4 was obtained with a similar approach to compound 2 (yield 91%) as a
colourless oil, [a]20 ꢀ17.3 (c 0.07, CH3OH), flit. [20] [a]31 ꢀ12.9 (0.33, CH3OH)g.
D
D