840 Chem. Res. Toxicol., Vol. 11, No. 7, 1998
Barlow et al.
In 1â(S) (2): UV λmax (methanol) 245 (shoulder), 252, 270
(shoulder) nm; 1H NMR (DMSO-d6) δ 8.33 (s, 1, H-8), 8.26 (s, 1,
H-2), 7.43-7.37 (m, 4, Ar-H, ortho and meta), 7.32-7.29 (m,
1, Ar-H, para), 6.31 (t, 1, H1′; J ) 6.7 Hz), 4.84-4.82 (dd, 1,
R-CH), 4.39 (m, 1, H3′), 4.32-4.28 (dd, 1, â-CHa; J ) 3.7 and
13.6 Hz), 3.92-3.89 (m, 1, â-CHb), 3.88-3.85 (m, 1, H4′), 3.62-
3.57 (m, 1, H5′a), 3.55-3.50 (m, 1, H5′b), 2.67-2.60 (m, 1, H2′a),
2.33-2.28 (m, 1, H2′b); +ve FAB MS m/z 373.1509 ([M + H]+;
calcd for C18H21N4O5, 373.1512).
methanol in water. The stereochemistry of the products was
assigned by comparison of the CD spectra of 1-substituted
adenosine-styrene oxides of known configuration which had
been synthesized previously (10). The N6R(S) product eluted
at 31 min, the N6R(R) product eluted at 38 min, the N6â(R)
product eluted at 42 min, and the N6â(S) product eluted at 53
min.
N6r(R) (5): UV λmax (methanol) 269 nm; 1H NMR (DMSO-
d6) δ 8.38 (s, 1, H-8), 8.14 (s, 1, H-2), 7.42 (d, 2, Ar-H, ortho; J
) 7.4 Hz), 7.30 (t, 2, Ar-H, meta; J ) 7.4 Hz), 7.20 (t, 1, Ar-H,
para; J ) 7.1 Hz), 6.34 (t, 1, H1′; J ) 6.1 Hz), 5.37 (br s, 1, R-CH),
4.56 (d, 1, H3′; J ) 5.0 Hz), 4.04 (d, 1, H4′; J ) 2.4 Hz), 3.80-
3.73 (m, 2, â-CHa,b), 3.62-3.59 (m, 1, H5′a), 3.52-3.49 (m, 1, H5′b),
2.72-2.69 (m, 1, H2′a), 2.27-2.22 (m, 1, H2′b); +ve FAB MS m/z
372.1625 ([M + H]+; calcd for C18H22N5O4, 372.1671).
N6r(S) (6): UV λmax (methanol) 269 nm; 1H NMR (DMSO-
d6) δ 8.30 (s, 1, H-8), 8.18 (s, 1, H-2), 7.44 (d, 2, Ar-H, ortho; J
) 7.4 Hz), 7.32 (t, 2, Ar-H, meta; J ) 7.4 Hz), 7.24 (t, 1, Ar-H,
para; J ) 7.3 Hz), 6.42 (t, 1, H1′; J ) 6.2 Hz), 5.48 (br s, 1, R-CH),
4.58-4.56 (d, 1, H3′; J ) 5.0 Hz), 4.06 (dd, 1, H4′; J ) 3.0 and
5.6 Hz), 3.94-3.86 (m, 2, â-CHa,b), 3.82 (dd, 1, H5′a; J ) 2.9 and
12.3 Hz), 3.73 (dd, 1, H5′b; J ) 3.3 and 12.3 Hz), 2.82-2.76 (m,
1, H2′a), 2.42-2.36 (m, 1, H2′b); +ve FAB MS m/z 372.1665 ([M
+ H]+; calcd for C18H22N5O4, 372.1671).
N6â(R) (7): UV λmax (methanol) 269 nm; 1H NMR (DMSO-
d6) δ 8.28 (s, 1, H-8), 8.18 (s, 1, H-2), 7.22-7.19 (m, 2, Ar-H,
ortho), 7.15-7.14 (m, 2, Ar-H, meta), 7.12-7.09 (m, 1, Ar-H,
para), 6.42 (t, 1, H1′; J ) 6.2 Hz), 4.95 (br s, 1, R-CH), 4.58-
4.56 (m, 1, H3′), 4.08-4.06 (m, 1, H4′), 3.93-3.89 (m, 1, â-CHa),
3.86-3.83 (m, 1, H5′a), 3.75-3.72 (m, 2, â-CHb and H5′b), 2.83-
2.78 (m, 1, H2′a), 2.42-2.38 (m, 1, H2′b); +ve FAB MS m/z
372.1665 ([M + H]+; calcd for C18H22N5O4, 372.1671).
Syn th esis of 1-(2-Hyd r oxy-1-p h en yleth yl)d eoxyin osin e
[In 1r(R) a n d In 1r(S), 3 a n d 4. Deoxyinosine (500 mg, 1.9
mmol, 1 equiv) and anhydrous potassium carbonate (400 mg,
2.8 mmol, 2 equiv) were suspended in trifluoroethanol (10 mL)
and stirred under reflux for 4 h. Racemic styrene oxide (1.2
mL, 10 mmol, 5.3 equiv) was added in four portions over a period
of 4 h. The reaction mixture was stirred under reflux for an
additional 16 h. The reaction mixture was concentrated in
vacuo and suspended in 40% (v/v) methanol and filtered. The
filtrate was applied to a Sephadex LH-20 column (2.8 × 80 cm)
and eluted at a flow rate of 1 mL/min with 40% (v/v) methanol.
Absorption of the eluate was monitored continuously at 254 nm,
and 8-mL fractions were collected. The products eluted in
fractions 57-67 and were identified by comparison of the UV
spectra with those of literature spectra for 1-substituted inosines
(21), and those fractions were pooled. The products were further
purified by reversed-phase HPLC eluting isocratically with 22%
(v/v) methanol in water. The â-substituted diastereomers eluted
at 60 min, and the two R-substituted diastereomers eluted at
69 and 83 min. The experimental procedures described above
were repeated at 1/10 of the scale with optically active styrene
oxides to identify the individual diastereomers. The earlier
running R-substituted diastereomer was identified as In1R(R),
and the later running R-substituted diastereomer was identified
as In1R(S).
N6â(S) (8): UV λmax (methanol) 269 nm; 1H NMR (DMSO-d6)
δ 8.34 (s, 1, H-8), 8.23 (s, 1, H-2), 7.38-7.36 (m, 2, Ar-H, ortho),
7.32 (t, 2, Ar-H, meta; J ) 7.4 Hz), 7.24 (d, 1, Ar-H, para; J )
7.3 Hz), 6.35 (t, 1, H1′; J ) 6.3 Hz), 4.88 (br s, 1, R-CH), 4.41 (m,
1, H3′; J ) 2.7 Hz), 3.89 (dd, 1, H4′; J ) 4.3 and 6.8 Hz), 3.72 (m,
1, â-CHa), 3.63-3.51 (m, 3, â-CHb and H5′a,b), 2.75-2.70 (m, 1,
In 1r(R) (3): UV λmax (methanol) 246 (shoulder), 252, 270
(shoulder) nm; 1H NMR (DMSO-d6) δ 8.46 (s, 1, H-8), 8.33 (s, 1,
H-2), 7.43-7.38 (m, 2, Ar-H, ortho), 7.37-7.36 (m, 2, Ar-H,
meta), 7.33-7.29 (m, 1, Ar-H, para), 6.31 (t, 1, H1′; J ) 6.6
Hz), 6.05-6.02 (m, 1, R-CH), 4.84-4.82 (m, 1, H3′), 4.39 (m, 1,
H4′), 4.32-4.27 (m, 1, â-CHa), 3.88-3.85 (m, 1, â-CHb), 3.61-
3.57 (m, 1, H5′a), 3.53-3.49 (m, 1, H5′b), 2.68-2.60 (m, 1, H2′a),
2.33-2.27 (m, 1, H2′b); +ve FAB MS m/z 373.1621 ([M + H]+;
calcd for C18H21N4O5, 373.1512).
H
2′a), 2.28-2.24 (m, 1, H2′b); +ve FAB MS m/z 372.1663 ([M +
H]+; calcd for C18H22N5O4, 372.1671).
Syn th esis of th e Dia ster eom er s of 1-(2-Hyd r oxy-1-p h e-
n yleth yl)a d en osin e [Ad o1r(R) a n d Ad o1r(S), 9 a n d 10]
a n d 1-(2-Hyd r oxy-2-p h en yleth yl)a d en osin e [Ad o1â(R) a n d
Ad o1â(S), 11 a n d 12]. Adenosine (300 mg, 1.12 mmol, 1 equiv)
and ammonium formate (50 mg) were dissolved in water (20
mL), and optically active styrene oxide (1 mL, 8.8 mmol, 7 equiv)
was added. The reaction mixture was stirred at 55 °C for 5 h
and then cooled to room temperature. The reaction mixture was
washed with diethyl ether (2 × 30 mL), and the aqueous phase
was applied to a Sephadex LH-20 column (2.8 × 80 cm) and
eluted at a flow rate of 1 mL/min with 30% (v/v) methanol.
Absorption of the eluate was monitored continuously at 254 nm,
and 8-mL fractions were collected. The products eluted in
fractions 35-46, before unreacted adenosine (fractions 58-82)
and N6-substituted compounds (fractions 96-113), and were
identified by comparison of the UV spectra with those of
literature spectra for 1-substituted adenosines (21), and those
fractions were pooled. The products were further purified by
reversed-phase HPLC eluting isocratically with 15% (v/v)
methanol in 50 mM ammonium formate at pH 6.0. Ado1â(R)
eluted at 18 min, Ado1â(S) eluted at 20 min, Ado1R(S) eluted
at 45 min, and Ado1R(R) eluted at 54 min. Their identities were
verified by comparison of UV and 1H NMR spectra with those
published (10).
In 1r(S) (4): UV λmax (methanol) 246 (shoulder), 252, 270
(shoulder) nm; 1H NMR (DMSO-d6) δ 8.45 (s, 1, H-8), 8.33 (s, 1,
H-2), 7.38-7.36 (m, 4, Ar-H, ortho and meta), 7.32-7.29 (m,
1, Ar-H, para), 6.31 (t, 1, H1′; J ) 6.7 Hz), 6.04 (dd, 1, R-CH; J
) 5.4 and 8.4 Hz), 4.38 (m, 1, H3′), 4.29 (t, 1, â-CHa; J ) 10.2
Hz), 4.10 (m, 1, â-CHb), 3.86 (dd, 1, H4′; J ) 4.4 Hz), 3.60-3.50
(m, 1, H5′a), 3.35-3.29 (m, 1, H5′b), 2.66-2.61 (m, 1, H2′a), 2.32-
2.27 (m, 1, H2′b); +ve FAB MS m/z 373.1480 ([M + H]+; calcd
for C18H21N4O5, 373.1512).
Syn th esis of th e Dia ster eom er s of N6-(2-Hyd r oxy-1-
p h en yleth yl)d eoxya d en osin e [N6r(R) a n d N6r(S), 5 a n d
6] a n d N6-(2-Hyd r oxy-2-p h en yleth yl)d eoxya d en osin e [N6â-
(R) a n d N6â(S), 7 a n d 8]. Deoxyadenosine (500 mg, 1.86 mmol,
1 equiv) and ammonium acetate (100 mg) were dissolved in 50%
(v/v) ethanol (70 mL) on warming. (R)- or (S)-Styrene oxide (1.8
mL, 15 mmol, 8 equiv) was added, and the reaction mixture
was stirred at room temperature for 96 h. The reaction mixture
was concentrated in vacuo, and the residue was washed with
diethyl ether (50 mL). The suspension was filtered, and the
solid was resuspended in 40% (v/v) methanol (20 mL). The
suspension was filtered, and the filtrate was applied to a
Sephadex LH-20 column (2.8 × 80 cm) and eluted at a flow rate
of 1 mL/min with 40% (v/v) methanol. Absorption of the eluate
was monitored continuously at 254 nm, and 8-mL fractions were
collected. The products eluted in fractions 83-106 and were
identified by comparison of the UV spectra with those of
literature spectra for N6-substituted adenosines (21), and those
fractions were pooled. The products were further purified by
reversed-phase HPLC eluting isocratically with 33% (v/v)
Syn th esis of th e Dia ster eom er s of 1-(2-Hyd r oxy-1-p h e-
n yleth yl)d eoxya d en osin e [d Ad o1r(R) a n d d Ad o1r(S), 13
a n d 14] a n d 1-(2-Hyd r oxy-2-p h en yleth yl)d eoxya d en osin e
[d Ad o1â(R) a n d d Ad o1â(S), 15 a n d 16]. As described above
for the preparation of 1-substituted adenosine-styrene oxides
except on the Sephadex LH-20 column (2.8 × 80 cm), the
products eluted in fractions 45-54, before unreacted deoxyad-
enosine (fractions 61-79) and N6-substituted compounds (frac-