Chemoenzymatic synthesis of naturally occurring (Z)-3-hexenyl 6-O-glycosyl-β-d-glucopyranosides

Article abstract of DOI:10.3987/COM-05-10474

Direct β-glucosidation between cis-3-hexen-1-ol and d-glucose (5) using the immobilized β-glucosidase from almonds with the synthetic prepolymer ENTP-4000 gave (Z)-3-hexenyl β-d-glucoside (1) in 17% yield. The coupling of the (Z-3-hexenyl O-β-d-glucopyran

Full text of DOI:10.3987/COM-05-10474

HETEROCYCLES, Vol. 65, No. 9, 2005
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HETEROCYCLES, Vol. 65, No. 9, 2005, pp. 2127 - 2137
Received, 6th June, 2005, Accepted, 6th July, 2005, Published online, 8th July, 2005
CHEMOENZYMATIC SYNTHESIS OF NATURALLY
OCCURRING (Z)-3-HEXENYL 6-O-GLYCOSYL-
β-D-GLUCOPYRANOSIDES
a,b
Masashi Kishida, Mikio Fujii, Yoshiteru Ida, and Hiroyuki Akita *
c
c
a
a
School of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama,
Funabashi, Chiba 274-8510, Japan
b
Tsukuba Research Institute, Novartis Pharma K.K. , 8 Ohkubo, Tsukuba-shi,
Ibaraki 300-2611, Japan
c
School of Pharmaceutical Sciences, Showa University, 1-5-8, Hatonodai,
Shinagawa-Ku, Tokyo 142-8555, Japan
Abstract- Direct β-glucosidation between cis-3-hexen-1-ol and D-glucose (5)
using the immobilized β-glucosidase from almonds with the synthetic
prepolymer ENTP-4000 gave (Z)-3-hexenyl β-D-glucoside (1) in 17% yield.
The coupling of the (Z)-3-hexenyl O-β-D-glucopyranoside congener (7) with
2,3,4-tri-O-benzoyl-α-D-xylopyranosyl bromide (8) gave the coupled product
(11). Similarly the coupling of 7 with 2,3,4-tri-O-benzoyl-α-L-arabinopyranosyl
bromide (9), and that of 7 with 2,3,4-tri-O-benzoyl-α-L-rhamnopyranosyl
bromide (10) afforded the coupled products (12 and 13), respectively.
Deprotection of the products (11, 12, and 13) afforded (Z)-3-hexenyl O-β-D-
xylopyranosyl-(1 → 6)-β-D-glucopyranoside (2), (Z)-3-hexenyl O-α-L-
arabinopyranosyl-(1→6)-β-D-glucopyranoside (3), and (Z)-3-hexenyl O-α-L-
rhamnopyranosyl- (1→6)-β-D-glucopyranoside (4), respectively.
(Z)-3-Hexenyl β-D-glucoside (1) is widely distributed in the plant,1 and was isolated from the leaves
of Pertya glabrescens,1a Epimedium grandiflorum var. thunbergium,1b the leaves of Celosia
argentea,1f and leaves of Thymus vulgaris.1l Moreover, three kinds of naturally occurring
(Z)-3-hexenyl 6-O-glycosyl-β-D-glucopyranoside congeners, (Z)-3-hexenyl O-β-D-xylopyranosyl-(1

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→ 6)-β-D-glucopyranoside2 (2), (Z)-3-hexenyl O-α-L-arabinopyranosyl-(1 → 6)-β-D-glucopyranoside3
(3) and (Z)-3-hexenyl O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside1f (4) were isolated from a
methanolic extract of leaves of Alangium platanifolium var. trilobim,2a Hippophae rhamnoides3 and
African Celosia argentea,1f respectively. Interestingly, compound (2) was found to exhibit growth
promotive activity of lettuce, whereas cis-3-hexen-1-ol, which is the aglycone of 2, inhibited the
germination of lettuce.1f To investigate their pharmacological activities, the synthesis of the
above-mentioned β-D-glucopyranoside congeners has aroused our interest. In this paper, we describe
the synthesis of (Z)-3-hexenyl β-D-glucopyranoside (1) and its naturally occurring (Z)-3-hexenyl
6-O-glycosyl-β-D-glucopyranoside congeners (2, 3 and 4) based on the selective β-glucosidation
between D-glucose (5) and cis-3-hexen-1-ol catalyzed by the immobilized β-glucosidase (EC
3.2.1.21) from almonds.
HOH2C
HO
HO
R1OH2C
HO
HO
HO
O
O
+
O
OH
OH
OH
5
R1 = H; (Z)-3-Hexenyl O-!-D-glucopyranoside (1)
O
HO
; (Z)-3-Hexenyl O-!-D-xylopyranosyl-(1!6)-!-D-glucopyranoside (2)
; (Z)-3-Hexenyl O-"-L-arabinopyranosyl-(1!6)-!-D-glucopyranoside (3)
R1 =
HO
OH
OH
O
R1 =
HO
OH
OH
HO
HO
Me
; (Z)-3-Hexenyl O-"-L-rhamnopyranosyl-(1!6)-!-D-glucopyranoside (4)
R1 =
O
Scheme 1
Enzymatic β-glucosidation
In case of the direct β-glucosidation between D-glucose (5) and primary alcohols using β-glucosidase
(EC 3.2.1.21) from almonds under thermodynamic conditions, a high concentration of a primary
alcohol or a medium with low water activity is reported to be effective.4 Meanwhile, the synthesis of
mono-β-D-glucopyranoside using 4-nitrophenyl β-D-glucopyranoside as a glycosyl donor was
reported previously by us.5 On the other hand, we reported the effectiveness of immobilization of
β-glucosidase (EC 3.2.1.21) from almonds with a photocross-linkable resin prepolymer (ENTP-4000)

HETEROCYCLES, Vol. 65, No. 9, 2005
2129
in the direct β-glucosidation between D-glucose (5) and 1,8-octanediol.6 Then we examined the direct
β-glucosidation between D-glucose (5) and cis-3-hexen-1-ol using the reported immobilized
β-glucosidase (EC 3.2.1.21)6 from almonds. When a large amount of cis-3-hexene-1-ol (25
equivalents) was used as an acceptor for D-glucose (5) in the presence of the immobilized
β-glucosidase, a 17% yield of (Z)-3-hexenyl O-β-D-glucopyranoside (1) was obtained. Moreover, the
same β-glucosidation using the recovered immobilized enzyme afforded 1 in 17% yield.
Synthesis of (Z)-3-hexenyl O-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside (2)
The tert-butyldimethylsilyl (TBDMS) protection of 1 gave a silyl ether (6) in 60 % yield, which was
subjected to consecutive benzoylation and deprotection of TBDMS group to give the desired
(Z)-3-hexenyl 2,3,4-tri-O-benzoyl-β-D-glucopyranoside (7) in 80 % yield (2 steps). On the other hand,
2,3,4-tri-O-benzoyl-α-D-xylopyranosyl bromide (8) was prepared by literature procedures.7 The
alcohol (7) was treated with 2 equivalents of bromide (8) in the presence of silver triflate (AgOTf)
and tetramethylurea (TMU) in CH2Cl2 to give the corresponding coupling product (11) in 69% yield.
Finally, treatment of 11 with NaOMe in MeOH-THF provided the synthetic (Z)-3-hexenyl
O-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside (2) in 85% yield. The spectral data (13C-NMR) and
26
specific rotation ([α]D –56.8° (c=0.90, MeOH)) of the synthetic 2 were identical with those
(13C-NMR and [α]D20 –56.7° (c=0.90, MeOH)) of natural product (2).2a
Synthesis of (Z)-3-hexenyl O-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside (3)
The coupling reaction of 7 and 2 equivalents of the known 2,3,4-tri-O-benzoyl-α-L-arabinopyranosyl
bromide8 (9) in the presence of silver triflate (AgOTf) and tetramethylurea (TMU) in CH2Cl2 gave the
coupled product (12) in 68% yield. Finally, treatment of 12 with NaOMe in MeOH-THF provided the
23
synthetic (Z)-3-hexenyl O-α-L-arabinopyranosyl-(1 → 6)-β-D-glucopyranoside (3, [α]D
–31.0°
(c=0.74, MeOH)) in 83% yield. The spectral data (1H- and 13C-NMR) of the synthetic 3 were
identical with those of natural product (3).3
Synthesis of (Z)-3-hexenyl O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (4)
The coupling reaction of 7 with 2 equivalents of the reported 2,3,4-tri-O-benzoyl-α-L-
rhamnopyranosyl bromide9 (10) in the presence of silver triflate (AgOTf) and tetramethylurea (TMU)
in CH2Cl2 gave the coupled product (13) in 56% yield. Finally, treatment of 13 with NaOMe in
MeOH-THF provided the synthetic (Z)-3-hexenyl O-α-L-rhamnopyranosyl-(1 → 6)-β-D-gluco-
pyranoside (4) in 96% yield. The spectral data (13C-NMR) of the synthetic 4 was identical with that
(13C-NMR in MeOH-d4) of natural product (4).1f The specific rotation ([α]D –53.9° (c=0.63,
25
20
MeOH)) of the synthetic 4 was consistent with that ( [α]D –48.26° (c=0.5, MeOH)) of natural product
(4).1f

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HETEROCYCLES, Vol. 65, No. 9, 2005
CONCLUSION
In conclusion, direct β-glucosidation between cis-3-hexen-1-ol and D-glucose (5) using the
immobilized β-glucosidase from almonds with the synthetic prepolymer ENTP-4000 gave a
(Z)-3-hexenyl O-β-D-glucoside (1) in 17% yield. The coupling of the (Z)-3-hexenyl
O-β-D-glucopyranoside congener (7) and 2,3,4-tri-O-benzoyl-α-D-xylopyranosyl bromide (8),
2,3,4-tri-O-benzoyl-α-L-arabinopyranosyl bromide (9), and 2,3,4-tri-O-benzoyl-α-L-rhamnopyranosyl
bromide (10) gave the coupled products (11, 12, and 13), respectively. Deprotection of the coupled
products (11, 12, and 13) afforded the synthetic (Z)-3-hexenyl O-β-D-xylopyranosyl-(1 →
6)-β-D-glucopyranoside (2), (Z)-3-hexenyl O-α-L-arabinopyranosyl-(1 → 6)-β-D-glucopyranoside (3),
and (Z)-3-hexenyl O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (4), respectively.
HOH2C
HOH2C
HO
HO
TBDMSOH2C
a
b
c
O
O
O
HO
HO
HO
HO
OH
O
O
OH
OH
OH
6
5
1
HOH2C
R1OH2C
BzO
BzO
R1OH2C
HO
HO
d
e
O
O
O
BzO
BzO
O
O
O
OBz
OBz
OH
7
O
O
O
BzO
BzO
BzO
BzO
HO
HO
11: R1 =
2: R1 =
BzO
BzO
OH
Br
8
OBz
OBz
OH
HO
O
O
O
Br
12: R1 =
3: R1 =
BzO
BzO
BzO
BzO
OH
9
OBz
Br
OBz
OH
BzO
BzO
Me
BzO
HO
13: R1 =
4: R1 =
BzO
HO
Me
O
O
O
Me
10
a; cis-3-hexen-1-ol / H2O / immobilized !-glucosidase with ENTP-4000, 50°C, 7 d, 17 %
b; TBDMSCl / pyridine / DMF, rt, 12 h, 60%
c; (i) BzCl / cat. DMAP/ pyridine, rt, overnight (ii) 1N HCl / THF, rt, 12 h, 2 steps 80%
d; 8 or 9 or 10 / AgOTf / tetramethylurea / CH2Cl2, 0°C-rt, 12 h, 56-69%
e; 25% NaOMe in MeOH / MeOH / THF, rt, 1 h, 83-96%
Scheme 2
EXPERIMENTAL
13
1H- and C-NMR spectra were recorded on a JEOL EX 400 spectrometer (Tokyo, Japan) or a Bruker
400 spectrometer. Spectra were recorded with 5-10% (w/v) solution in CDCl3 or methanol-d4, with
Me4Si as an internal reference. Melting points were determined on a Yanaco MP-3S micromelting

HETEROCYCLES, Vol. 65, No. 9, 2005
2131
point apparatus and are uncorrected. Optical rotations were measured on a JASCO DIP-370 digital
polarimeter. The FAB MS spectra were obtained with a JEOL JMS-AX 500 (matrix; glycerol and
m-nitrobenzyl alcohol) spectrometer.
IR spectra were recorded on a JASCO FT/IR-300
spectrophotometer. All evaporations were performed under reduced pressure. For column
chromatography, silica gel (Kieselgel 60) was employed and for flash column chromatography, silica gel
(Silica Gel 60N, spherical, neutral, 40-50 µm) was employed.
Immobilization of β-D-glucosidase using a prepolymer
β-D-Glucosidase (EC 3.2.1.21) from almonds was purchased from Sigma Chemical Co. (G-0395,
2.5-3.6 U/mg). Immobilization of β-D-glucosidase from almonds on the photocross-linkable resin
prepolymer (ENTP-4000) was carried out using the following procedure. One gram of ENTP-4000
was mixed with 10 mg of a photosensitizer, benzoin ethyl ether, and 74 mg of β-D-glucosidase from
almonds (3.4 units/mg). The mixture was layered on a sheet of transparent polyester film (thickness,
ca. 0.5 mm). The layer was covered with transparent thin film and then illuminated with chemical
lamps (wavelength range, 300-400 nm) for 3 min. The gel film thus obtained was cut into small
pieces (0.5 x 5 x 5 mm) and used for the bioconversion reaction.
Enzymatic synthesis of (Z)-3-hexenyl O-β-D-glucopyranoside (1)
1) A mixture of D-glucose (5) (1.10 g, 6.1 mmol), cis-3-hexen-1-ol (18 mL, 15.3 g, 153 mmol), water
(2.0 mL), and the immobilized β-glucosidase (250 units) was incubated for 7 days at 50°C. The
reaction mixture was filtered off and the immobilized β-glucosidase was washed with AcOEt (3.0
mL). The combined filtrate was directly chromatographed on silica gel (25 g) to give cis-3-hexen-1-ol
(9.73 g, 64% recovery) from the CH2Cl2/MeOH = 25:1 eluent and β-glucoside (1, 0.271g, 17%) as a
white solid from the CH2Cl2/MeOH = 10:1 eluent. 1: mp 79.4-80.3 °C; [α] D 23 –32.1 ° (c = 1.10,
MeOH){lit. [α] D21 –35.5° (c = 2.75, MeOH)1b, [α] D29 –43.8° (c = 0.73, MeOH) 1g, [α] D26 –40.6° (c =
1
0.19, MeOH) 1j}; IR (KBr) 3346, 2930, 1374, 1163, 1079, 1033 cm–1; H NMR (methanol-d4, 400
MHz) δ: 5.49-5.34 (m, 2H), 4.27 (d, 1H, J = 7.8 Hz), 3.90-3.84 (m, 2H), 3.69-3.64 (m, 1H), 3.54 (dt,
1H, J = 9.6, 6.8 Hz), 3.37-3.23 (m, 3H), 3.17 (dd, 1H, J = 7.8, 8.8 Hz), 2.38 (td, 2H, J = 6.8, 6.8 Hz),
13
2.07 (dq, 2H, J = 7.1, 7.6 Hz), 0.96 (t, 3H, J = 7.6 Hz); C NMR (methanol-d4, 100 MHz) δ: 134.5,
125.9, 104.3, 78.1, 77.9, 75.1, 71.6, 70.5, 62.8, 28.9, 21.5, 14.6; Anal. Calcd for C12H22O6: C, 54.95; H,
8.45. Found: C, 54.70; H, 8.33.
2) A mixture of D-glucose (5) (1.10 g, 6.1 mmol), cis-3-hexen-1-ol (18 mL, 15.3 g, 153 mmol), water (2
mL), and the recovered immobilized β-glucosidase was incubated for 7 days at 50°C. The
reaction mixture was worked up in the same way as 1) to give cis-3-hexen-1-ol (14.5 g, 95%
recovery) and β-glucoside (1, 0.274 g, 17%).

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(Z)-3-Hexenyl 6-O-tert-butyldimethylsilyl-β-D-glucopyranoside (6)
A mixture of 1 (2.56 g, 9.8 mmol) and pyridine (1.16 g, 14.7 mmol) in DMF (10 mL) was treated
with tert-butyldimethylsilyl chloride (7.77 g, 11.7 mmol) at 0°C and stirred at rt for 18 h. The
reaction mixture was recooled at 0°C and treated with tert-butyldimethylsilyl chloride (TBDMSCl,
0.30 g, 2.0 mmol). After stirred at 0-5 °C for 2 h, the reaction mixture was diluted with 1N HCl (20
mL) and extracted with AcOEt. The organic layer was washed with water (100 mL), saturated
aqueous NaHCO3, and brine. The organic layer was dried over MgSO4 and evaporated to give a
residue, which was purified by flash column chromatography on silica gel (120 g, CH2Cl2/MeOH
27
(20:1-15:1)) to afford 6 (2.20 g, 60%) as a colorless solid. 6: mp 78.5-80.5 °C (CH2Cl2/MeOH); [α]D
1
-38.3° (c = 0.89, CHCl3); IR (KBr) 3472, 2930, 2856, 1251, 1148, 1059, 837, 775 cm–1; H NMR
(CDCl3, 400 MHz) δ: 5.51-5.44 (m, 1H), 5.36-5.29 (m, 1H), 4.28 (d, 1H, J = 7.5 Hz), 3.91-3.82 (m,
5H), 3.59-3.48 (m, 3H), 3.38-3.32 (m, 3H), 2.37 (td, 2H, J = 6.0, 6.0 Hz), 2.00 (dq, 2H, J = 6.0, 7.6
13
Hz), 0.95 (t, 3H, J = 7.6 Hz), 0.90 (s, 9H), 0.093 (s, 3H), 0.087 (s, 3H); C NMR (CDCl3, 100 MHz)
δ: 134.1, 124.2, 102.4, 76.2, 74.6, 73.4, 72.4, 69.4, 64.4, 27.7, 25.8, 20.6, 18.2, 14.2, -5.4; Anal.
Calcd for C18H38O6Si: C, 57.41; H, 9.64. Found: C, 57.13; H, 9.51.
(Ζ)-3-Hexenyl 2,3,4-tri-O-benzoyl-β-D-glucopyranoside (7)
A mixture of 6 (61 mg, 0.16 mmol), benzoyl chloride (100 mg, 0.71 mmol) and
4-N,N-dimethylaminopyridine (DMAP, 2 mg) in pyridine (0.8 mL) was stirred at rt for 16 h. The
reaction mixture was diluted with 1N HCl and extracted with AcOEt. The organic layer was washed
with 1N HCl, saturated aqueous NaHCO3, and brine. The organic layer was dried over MgSO4 and
evaporated to give a crude (Z)-3-hexenyl 2,3,4-tri-O-benzoyl-6-tert-butyldimethylsilyl-β-D-gluco-
pyranoside. The crude product was mixed with 1N HCl (0.5 mL) in THF (1.0 mL) and stirred at rt for
12 h. The reaction mixture was diluted with saturated aqueous NaHCO3 and extracted with AcOEt.
The organic layer was washed with brine, dried over MgSO4 and evaporated to give a residue, which
was purified by flash column chromatography on silica gel (5 g, n-hexane /AcOEt (5:1-2:1)) to afford
7 (74 mg, 80%) as a colorless syrup. 7: [α]D27 –7.8° (c= 0.57, CHCl3); IR (KBr) 3508, 2962, 1732, 1262,
1
1094, 1028, 710 cm–1; H NMR (CDCl3, 400 MHz) δ: 7.98-7.92 (m, 4H), 7.86-7.82 (m, 2H),
7.55-7.50 (m, 2H), 7.45-7.36 (m, 5H), 7.30-7.26 (m, 2H), 5.93 (t, 1H, J = 9.8 Hz), 5.53-5.46 (m, 2H),
5.31-5.25 (m, 1H), 5.22-5.17 (m, 1H), 4.85 (d, 1H, J = 7.8 Hz), 3.94 (dt, 1H, J = 6.8, 9.6 Hz), 3.87 (d,
1H, J = 10.9 Hz), 3.82-3.72 (m, 2H), 3.55 (dt, 1H, J = 7.1, 9.6 Hz), 2.65 (br s, 1H), 2.29 (td, 2H, J =
13
7.1, 7.1 Hz), 1.93 (dq, 2H, J = 7.3, 7.6 Hz), 0.87 (t, 3H, J = 7.6 Hz); C NMR (CDCl3, 100 MHz) δ:
166.0, 165.9, 165.0, 134.0, 133.7, 133.2, 133.1, 129.9, 129.74, 129.73, 129.4, 128.9, 128.6, 128.5,
128.3, 123.9, 101.3, 74.6, 72.8, 71.9, 69.9, 69.6, 61.4, 27.6, 20.5, 14.1; Anal. Calcd for C33H34O9: C,
68.82; H, 6.00. Found: C, 68.98; H, 5.96.

HETEROCYCLES, Vol. 65, No. 9, 2005
2133
(Z)-3-Hexenyl 2,3,4,2’,3’,4’-O-hexabenzoyl-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside (11)
A 50-mL three-necked round-bottom flask covered with aluminum foil, was charged with 7 (0.29 g, 0.50
mmol), 2,3,4-tri-O-benzoyl-α-D-xylopyranosyl bromide7 (8) (0.52 g, 1.0 mmol), tetramethylurea (0.17 g,
1.5 mmol) and CH2Cl2 (2.0 mL). To this solution was added AgOTf (0.26 g, 1.0 mmol) at 0 °C under
argon atmosphere and the mixture was stirred for 24 h at rt. The reaction mixture was quenched with
saturated aqueous NaHCO3 and extracted with AcOEt. The organic layer was washed with brine, dried
over MgSO4 and evaporated to dryness. The residue was purified by flash column chromatography on
silica gel (20 g, n-hexane/AcOEt (4:1-5:2)) to afford 11, which was recrystallized from acetone/n-hexane
to give a pure 11 (0.35 g, 69%) as a colorless solid. 11: mp 202.8-203.5 °C; [α] D27 –29.7° (c= 0.59,
1
CHCl3); IR (KBr) 1730, 1261, 1177, 1101, 1029, 710 cm–1; H NMR (CDCl3, 400 MHz) δ: 8.01-7.97 (m,
6H), 7.94-7.88 (m, 4H), 7.79-7.76 (m, 2H), 7.55-7.47 (m, 5H), 7.43-7.31 (m, 11H), 7.28-7.23 (m, 2H),
5.83 (t, 1H, J = 9.8 Hz), 5.74 (t, 1H, J = 7.0 Hz), 5.45-5.36 (m, 3H), 5.27-5.16 (m, 2H), 5.12-5.06 (m, 1H),
4.92 (d, 1H, J = 5.3 Hz), 4.70 (d, 1H, J = 7.8 Hz), 4.40 (dd, 1H, J = 4.3, 12.4 Hz), 4.07-4.98 (m, 2H), 3.82
(dd, 1H, J = 6.6, 11.1 Hz), 3.73-3.65 (m, 2H), 3.28 (dt, 1H, J = 6.8, 9.4 Hz), 2.10 (td, 2H, J = 6.8, 6.8 Hz),
13
1.87 (dq, 2H, J = 7.3, 7.6 Hz), 0.84 (t, 3H, J = 7.6 Hz); C NMR (CDCl3, 100 MHz) δ: 165.8, 165.5,
165.34, 165.27, 165.01, 164.98, 133.7, 133.44, 133.38, 133.3, 133.2, 133.13, 133.05, 129.86, 129.73,
129.5, 129.3, 129.2, 129.1, 128.84, 128.79, 128.5, 128.41, 128.38, 128.3, 128.24, 128.22, 124.2, 101.1,
100.3, 73.9, 72.9, 71.9, 70.1, 70.0, 69.70, 69.68, 69.0, 67.9, 61.0, 27.4, 20.5, 14.1; Anal. Calcd for
C59H54O16: C, 69.29; H, 5.38. Found: C, 69.54; H, 5.34.
(Z)-3-Hexenyl O-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside (2)
Compound (11) (0.15 g, 0.15 mmol) was dissolved in 2 mL of methanol/THF (1:1) and 25% NaOMe in
MeOH (0.035 g, 0.17 mmol) was added. The solution was stirred for 30 min. A small amount of ion
exchange resin (Amberlyst 15, H+-form) was added to remove sodium ions. The reaction mixture was
diluted with methanol and resin was filtered off and washed thoroughly. The filtrate was evaporated with
silica gel (0.50 g) to dryness and the residue was purified by flash column chromatography on silica gel (8
g, CH2Cl2/MeOH (5:1)) to afford 2 (0.049 g, 85 %) as a colorless amorphous solid. 2: mp 74.0-75.0 °C;
[α]D26 –56.8° (c= 0.90, MeOH){lit. [α]D –56.7° (c= 0.90, MeOH)2a }; IR (KBr) 3386, 2878, 1370, 1167,
1042 cm–1; 1H NMR (methanol-d4, 400 MHz) δ: 5.49-5.35 (m, 2H), 4.31 (d, J = 7.3 Hz, 1H), 4.26 (d, 1H,
J = 7.8 Hz), 4.08 (dd, 1H, J = 2.0, 11.4 Hz), 3.86 (dd, 1H, J = 5.6, 11.6 Hz), 3.84 (td, 1H, J = 7.1, 9.4 Hz),
3.74 (dd, 1H, J = 5.5, 11.4 Hz), 3.54 (td, 1H, J = 7.3, 9.4 Hz), 3.48 (ddd, 1H, J = 5.3, 8.6, 10.1 Hz),
3.44-3.40 (m, 1H), 3.35-3.28 (m, 3H), 3.22-3.15 (m, 3H), 2.38 (td, 2H, J = 6.8, 6.8 Hz), 2.08 (dq, 2H, J =
13
7.6, 7.6 Hz), 0.97 (t, 3H, J = 7.6 Hz); C NMR (methanol-d4, 100 MHz) δ: 134.5 (C-4), 125.9 (C-3),
105.5 (Xyl-C1), 104.4 (Glc-C1), 78.0 (Glc-C3), 77.7 (Xyl-C3), 77.0 (Glc-C5), 75.0 (Xyl-C2), 74.9

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HETEROCYCLES, Vol. 65, No. 9, 2005
(Glc-C2), 71.4 (Glc-C4), 71.2 (Xyl-C4), 70.6 (C1), 69.7 (Glc-C6), 66.9 (Xyl-C5), 28.8 (C-2), 21.5 (C-5),
14.6 (C-6); HR FAB-MS m/z: Calcd for C17H30O10: 395.1917 (M+1)+ . Found: 395.1905.
(Z)-3-Hexenyl 2,3,4,2’,3’,4’-O-hexabenzoyl-α-L-arabinopyranosyl-(1→6)-β-D-glucopyranoside (12)
A 50-mL three-necked round-bottom flask covered with aluminum foil, was charged with 7 (0.57 g, 1.0
mmol), 2,3,4-tri-O-benzoyl-α-L-arabinopyranosyl bromide8 (9) (1.04 g, 2.0 mmol), tetramethylurea (0.34
g, 3.0 mmol) and CH2Cl2 (4.0 mL). To this solution was added AgOTf (0.52 g, 2.0 mmol) at 0 °C under
argon atmosphere and the mixture was stirred for 24 h at rt. The reaction mixture was quenched with
saturated aqueous NaHCO3 and extracted with AcOEt. The organic layer was washed with brine, dried
over MgSO4 and evaporated to dryness. The residue was purified by flash column chromatography on
silica gel (80 g, n-hexane/AcOEt (3:1-2:1)) to afford 12 (0.79 g, 78 %), which was recrystallized from
ether to give a highly pure 12 (0.56 g, 55%) as a colorless solid. 12: mp 136.8-138.5 °C; [α]D27 +67.4° (c=
0.59, CHCl3); (KBr) 1731, 1452, 1261, 1095, 1029, 710 cm–1; 1H NMR (CDCl3, 400 MHz) δ: 8.01 (d, 2H,
J = 7.3 Hz), 7.95-7.87 (m, 6H), 7.78-7.76 (m, 2H), 7.59-7.54 (m, 1H), 7.53-7.46 (m, 4H), 7.43-7.34 (m,
11H), 7.28-7.24 (m, 2H), 5.81 (t, 1H, J = 9.8 Hz), 5.72 (dd, 1H, J = 6.1, 8.4 Hz), 5.67-5.64 (m, 1H), 5.60
(dd, 1H, J = 3.5, 8.6 Hz), 5.39 (dd, 1H, J = 2.3, 9.8 Hz), 5.36 (dd, 1H, J = 4.0, 9.9 Hz), 5.19-5.13 (m, 1H),
5.08-5.01 (m, 1H), 4.84 (d, 1H, J = 6.1 Hz), 4.67 (d, 1H, J = 7.8 Hz), 4.26 (dd, 1H, J = 4.3, 12.9 Hz), 4.08
(dd, 1H, J = 1.6, 11.4 Hz), 4.04-3.98 (m, 1H), 3.86 (dd, 1H, J = 2.2, 12.6 Hz), 3.82 (dd, 1H, J = 7.3, 11.1
Hz), 3.61 (td, 1H, J = 6.6, 9.6 Hz), 3.22 (td, 1H, J = 6.0, 9.6 Hz), 2.04 (td, 2H, J = 6.3, 6.3 Hz), 1.85 (dq,
2H, J = 7.3, 7.6 Hz), 0.83 (t, 3H, J = 7.6 Hz); 13C NMR (CDCl3, 100 MHz) δ: 165.7, 165.6, 165.5, 165.3,
165.1, 165.0, 133.6, 133.43, 133.35, 133.32, 133.1, 133.0, 129.85, 129.82, 129.78, 129.7, 129.43, 129.35,
129.3, 129.1, 128.8, 128.7, 128.44, 128.38, 128.21, 124.3, 101.0, 100.8, 73.9, 72.9, 71.9, 70.3, 69.8, 69.7,
69.6, 68.3, 68.2, 62.3, 27.3, 20.5, 14.1 ; Anal. Calcd for C59H54O16: C, 69.36; H, 5.34. Found: C, 69.54; H,
5.34.
(Z)-3-Hexenyl O-β-D-arabinopyranosyl-(1→6)-β-D-glucopyranoside (3)
Compound (12) (0.30 g, 0.29 mmol) was dissolved in 4 mL of methanol/THF (1:1) and 25% NaOMe
in MeOH (0.072 g, 0.35 mmol) was added. The solution was stirred for 1 h. A small amount of ion
exchange resin (Amberlyst 15, H+-form) was added to remove sodium ions. The reaction mixture was
diluted with methanol and resin was filtered off and washed thoroughly. The filtrate was evaporated
with silica gel (1.0 g) to dryness and the residue was purified by flash column chromatography on
silica gel (8 g, CH2Cl2/MeOH (5:1)) to afford 3 (0.096 g, 83 %) as a colorless amorphous solid. 3: mp
23
69.0-71.0 °C; [α]
–31.0° (c= 0.74, MeOH); IR (KBr) 3415, 2878, 1370, 1257, 1080, 781, 644
D
1
cm–1; H NMR (methanol-d4, 400 MHz) δ: 5.49-5.35 (m, 2H), 4.31 (d, J = 6.8 Hz, 1H), 4.26 (d, 1H, J
= 7.8 Hz), 4.08 (dd, 1H, J = 2.3, 11.4 Hz), 3.88-3.83 (m, 2H), 3.81-3.78 (m, 1H), 3.73 (dd, 1H, J =

HETEROCYCLES, Vol. 65, No. 9, 2005
2135
5.6, 11.4 Hz), 3.59 (dd, 1H, J = 6.8, 8.8 Hz), 3.55-3.50 (m, 3H), 3.45-3.41 (m, 1H), 3.36-3.30 (m, 2H),
3.19-3.15 (m, 1H) 2.37 (td, 2H, J = 7.1, 7.1 Hz), 2.07 (dq, 2H, J = 7.6, 7.6 Hz), 0.97 (t, 3H, J = 7.6
13
Hz); C NMR (methanol-d4, 100 MHz) δ: 134.5 (C-4), 125.9 (C-3), 105.1 (Ara-C1), 104.4 (Glc-C1),
77.9 (Glc-C3), 76.9 (Glc-C5), 75.0 (Glc-C2), 74.2 (Ara-C3), 72.4 (Ara-C2), 71.6 (Glc-C4), 70.6
(C-1), 69.5 (Glc-C6 and Ara-C4), 66.7 (Ara-C5), 28.8 (C-2), 21.6 (C-5), 14.6 (C-6); HR FAB-MS
m/z: Calcd for C17H30O10: 395.1917 (M+1)+ . Found: 395.1912.
(Z)-3-Hexenyl 2,3,4,2’,3’,4’-O-hexabenzoyl-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (13)
A 50-mL three-necked round-bottom flask covered with aluminum foil, was charged with 7 (0.57 g, 1.0
mmol),
2,3,4-tri-O-benzoyl-α-L-rhamnopyranosyl
bromide9 (10)
(1.08
g,
2.0
mmol),
tetramethylurea (0.35 g, 3.0 mmol) and CH2Cl2 (4.0 mL). To this solution was added AgOTf (0.51 g,
2.0 mmol) at 0 °C under argon atmosphere and the mixture was stirred for 12 h at rt. The reaction
mixture was quenched with saturated aqueous NaHCO3 and extracted with AcOEt. The organic layer
was washed with brine, dried over MgSO4 and evaporated to dryness. The residue was purified by
flash column chromatography on silica gel (80 g, n-hexane/AcOEt (3:1-2:1)) to afford 13 (0.90 g,
87%), which was recrystallized from acetone/n-hexane to give a pure 13 (0.58 g, 56%) as a colorless
solid. 13: mp 175.0-176.0 °C; [α] D27 +54.8° (c= 0.59, CHCl3); IR (KBr) 1732, 1263, 1100, 1028, 708
1
cm–1; H NMR (CDCl3, 400 MHz) δ: 8.08-8.05 (m, 2H), 7.99-7.93 (m, 6H), 7.85-7.82 (m, 2H),
7.82-7.79 (m, 2H), 7.62-7.58 (m, 1H), 7.54-7.35 (m, 13H), 7.31-7.23 (m, 4H), 5.90 (t, 1H, J = 9.6
Hz), 5.77 (dd, 1H, J = 3.3, 10.1 Hz), 5.70 (dd, 1H, J = 1.8, 3.3 Hz), 5.63 (t, 1H, J = 10.1 Hz), 5.50 (dd,
1H, J = 7.8, 9.8 Hz), 5.45 (t, 1H, J = 9.8 Hz), 5.19-5.16 (m, 3H), 4.87 (d, 1H, J = 7.8 Hz), 4.16-4.10
(m, 2H), 3.98 (td, 1H, J = 6.6, 9.4 Hz), 3.94-3.91 (m, 2H), 3.57 (td, 1H, J = 7.1, 9.4 Hz), 2.26 (td, 2H,
13
J = 6.8, 6.8 Hz), 1.91-1.83 (m, 2H), 1.27 (d, 3H, J = 6.3 Hz), 0.81 (t, 3H, J = 7.6 Hz); C NMR
(CDCl3, 100 MHz) δ: 165.8, 165.7, 165.40, 165.37, 165.1, 133.7, 133.5, 133.4, 133.3, 133.2, 133.1,
133.0, 129.9, 129.8, 129.71, 129.66, 129.5, 129.4, 129.3, 129.2, 128.9, 128.7, 128.53, 128.47, 128.4,
128.3, 128.2, 124.2, 101.2, 98.3, 74.5, 72.9, 71.9, 71.8, 70.5, 70.1, 69.8, 67.2, 66.9, 27.5, 20.5, 17.6,
14.1; Anal. Calcd for C60H56O16: 68.76; H, 5.46. Found: C, 68.71; H, 5.51.
(Z)-3-Hexenyl O-α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranoside (4)
Compound (13) (0.30 g, 0.29 mmol) was dissolved in 4 mL of methanol/THF (1:1) and 25% NaOMe
in MeOH (0.072 g, 0.35 mmol) was added. The solution was stirred for 1 h. A small amount of ion
exchange resin (Amberlyst 15, H+-form) was added to remove sodium ions. The reaction mixture was
diluted with methanol and resin was filtered off and washed thoroughly. The filtrate was evaporated
with silica gel (1.0 g) to dryness and the residue was purified by flash column chromatography on
silica gel (8 g, CH2Cl2/MeOH (5:1)) to afford 4 (0.114 g, 96 %) as a colorless amorphous solid. 4: mp

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HETEROCYCLES, Vol. 65, No. 9, 2005
74.5-76.0 °C; [α] D25 –53.9° (c= 0.63, MeOH){lit. [α] D20 –48.26° (c= 0.50, MeOH) 1f }; IR (KBr) 3373,
1
2931, 1372, 1049, 614 cm–1; H NMR (methanol-d4, 400 MHz) δ: 5.48-5.35 (m, 2H), 4.74 (d, 1H, J =
1.3 Hz), 4.25 (d, 1H, J = 7.8 Hz), 3.97 (dd, 1H, J = 1.8, 11.1 Hz), 3.84-3.78 (m, 2H), 3.70-3.63 (m,
2H), 3.61 (dd, 1H, J = 6.1, 11.4 Hz), 3.53 (td, 1H, J = 7.6, 9.4 Hz), 3.41-3.29 (m, 3H), 3.27 (t, 1H, J =
9.1 Hz), 2.38 (td, 2H, J = 6.8, 6.8 Hz), 2.08 (qd, 2H, J = 7.3, 7.3 Hz), 1.26 (d, 3H, J = 6.1 Hz), 0.97 (t,
3H, J = 7.3 Hz); 13C NMR (methanol-d4, 100 MHz) δ: 134.5 (C-4), 125.9 (C-3), 104.4 (Glc-C1),
102.3 (Rham-C1), 78.1 (Glc-C3), 76.8 (Glc-C5), 75.1 (Glc-C2), 74.0 (Rham-C4), 72.4 (Rham-C3),
72.2 (Rham-C2), 71.6 (Glc-C4), 70.6 (C-1), 69.8 (Rham-C5), 68.1 (Glc-C6), 28.8 (C-2), 21.5 (C-5),
18.0 (Rham-C6), 14.7 (C-6); HR FAB-MS m/z: Calcd for C18H32O10: 409.2074 (M+1)+ . Found: 409.2050.
ACKNOWLEDGEMENT
The authors are grateful to Dr. N. Uchiyama at Nihon University, for generously providing the specific
rotation and the spectral data (1H- and 13C-NMR) of natural product (3).
REFERENCES AND NOTE
1.
a) S. Nagumo, K. Kawai, H. Nagase, T. Inoue, and M. Nagai, Yakugaku Zasshi, 1984, 104, 1223.
b) T. Miyase, A. Ueno, N. Takizawa, H. Koayashi, and H. Oguchi, Chem. Pharm. Bull., 1988, 36,
2475. c) K. Mizutani, M. Yuda, O. Tanaka, Y. Saruwatari, T. Fuwa, M.-R. Jia, Y.-K. Ling, and
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Sakata, Biosci. Biotechnol. Biochem., 1996, 60, 1815. e) S. Yamamura, K. Ozawa, K. Ohtani, R.
Kasai, and K. Yamasaki, Phytochemistry, 1998, 48, 131. f) A. Sawabe, T. Obata, Y. Nochika, M.
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Tamaki, H. Otsuka, and T. Ide, J. Nat. Prod., 1999, 62, 1074. h) B. Bonnlaender and P.
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2001, 67, 482. j) L. Jiang, H. Kojima, K. Yamada, A. Kobayashi, and K. Kubota, J. Agric. Food
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a) H. Otsuka, Y. Takeda, and K. Yamasaki, Phytochemistry, 1990, 29, 3681. b) M. Nishikitani, D.
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a) According to Dr. T. Uchiyama’s private communication, isolation and structural elucidation of
natural product (3) from Hippophae rhamnoides were reported as a poster presentation at the 123th
Annual Meeting of Pharmaceutical Society of Japan (N. Machida, M. Makino, T. Uchiyama, S.
Kitanaka, and Y. Fujimoto, Abstract Paper (II), p. 152 (2003)). Low value of specific rotation of 3

HETEROCYCLES, Vol. 65, No. 9, 2005
2137
was presumably contributed to the contamination of a small amount of impurity, but structural
elucidation was carried out by spectrospecific analysis and chemical degradation procedure. b)
1
Spectral data of natural product (3): Yellow amorphous powder; [α]D –3.5° (c=1, MeOH); H NMR
(methanol-d4, 300 MHz) δ: 5.40 (m, 2H), 4.30 (d, J = 6.7 Hz, 1H), 4.26 (d, 1H, J = 7.9 Hz), 4.08
(dd, 1H, J = 2.3, 11.1 Hz), 3.83 (m, 2H), 3.72 (dd, 1H, J = 5.3, 10.6 Hz), 3.55 (m, 4H), 2.37 (br
quart, 2H, J = 7.0 Hz), 2.07 (br quin, 2H, J = 8.0 Hz), 0.97 (t, 3H, J = 8.0 Hz); 13C NMR
(methanol-d4, 100 MHz) δ: 133.2 (C-4), 124.6 (C-3), 103.9 (Ara-C1), 103.2 (Glc-C1), 76.8
(Glc-C3), 75.7 (Glc-C5), 73.9 (Glc-C2), 73.1 (Ara-C3), 71.2 (Ara-C2), 70.5 (Glc-C4), 69.5 (C-1),
68.4 (Glc-C6 and Ara-C4), 65.6 (Ara-C5), 27.8 (C-2), 20.6 (C-5), 13.7 (C-6); HR FAB-MS m/z:
Calcd for C17H30O10: 393.17607 (M-H)- . Found: 393.17602.
4.
5.
6.
7.
8.
9.
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H. Akita, E. Kawahara, and K. Kato, Tetrahedron: Asymmetry, 2004, 15, 1623.
G. Hewitt, H. G. Fletcher Jr., and C. S. Hudson, J. Am. Chem. Soc., 1947, 69, 921.
G. Hewitt, J. Am. Chem. Soc., 1947, 69, 1145.
R. K. Ness, H. G. Fletcher Jr., and C. S. Hudson, J. Am. Chem. Soc., 1951, 73, 296.