3
242
P. Ciuffreda et al. / Tetrahedron 56 (2000) 3239±3243
0
85%); Mp 1658C (from CHCl ) (lit. 166±1688C);
0
0
5
(
[
-O-Acetyl-3 -deoxyadenosine (10a). Y9 ield: 0.498 g
(1H, dd, J4.7, 4.7 Hz, 5 -OH), 4.49 (1H, dddd, J2.0,
1
0
2.0, 3.3, 5.4 Hz, H-2 ), 4.35 (1H, dddd, J4.7, 4,7, 6.0,
3
2
5
19
0
0
a] 223.7 (c 1, MeOH) (lit. 221.2, c 0.5 in MeOH);
9.4 Hz, H-4 ), 3.68 (1H, ddd, J4.7, 4.7, 12.0 Hz, H-5 a),
D
1
0
H NMR (CD OD) d 8.25 (1H, s, H-2), 8.20 (1H, s, H-8),
3
3.52 (1H, ddd, J4.7, 4.7, 12.0 Hz, H-5 b), 2.20 (1H, ddd,
0
0
5
5
.99 (1H, d, J2.0 Hz, H-1 ), 4.79 (1H, ddd, J2.0, 2.0,
J5.4, 9.4, 12.7 Hz, H-3 a), 1.89 (1H, ddd, J2.0, 6.0,
0
0
.6 Hz, H-2 ), 4.68 (1H, dddd, J2.7, 3.4, 6.0, 9.8 Hz,
12.7 Hz, H-3 b).
0
0
H-4 ), 4.35 (1H, dd, J3.4, 10.0 Hz, H-5 a), 4.32 (1H, dd,
0
0
0
J2.7, 10.0 Hz, H-5 b), 2.29 (1H, ddd, J5.6, 9.8, 14.0 Hz,
2 ,3 -O-Diacetylinosine (11a). 0.090 g (90%); Mp 212±
0
3H, s, OCOCH ).
0
22
H-3 a), 2.09 (1H, ddd, J2.0, 6.0, 14.0 Hz, H-3 b), 2.03
2138C (from MeOH) (lit. 2158C). Rf0.34 (CHCl /
3
2
5
1
(
MeOH 4:1); [a] 238.6 (c 1, MeOH); H NMR
3
D
(
CD OD) d 8.35 (1H, s, H-2), 8.09 (1H, s, H-8), 6.25 (1H,
3
0
0
Synthesis of compounds 8b and 10b: General pro-
cedure. A typical hydrolysis was performed dissolving
compounds 8e or 10c (1.2 mmol) in acetone (2.0 ml) and
adding to this solution 1.0 g of CAL dispersed in 0.1 M
phosphate buffer pH7.0 (10 ml). The mixture was stirred
at room temperature, monitoring the reactions by TLC
d, J6.3 Hz, H-1 ), 5.88 (1H, dd, J6.3, 6.3 Hz, H-2 ), 5.61
0
(1H, dd, J3.5, 6.3 Hz, H-3 ), 4.33 (1H, ddd, J2.8, 2.8,
0
0
3.5 Hz, H-4 ), 3.89 (1H, dd, J2.8, 12.6 Hz, H-5 a), 3.81
0
(1H, dd, J2.8, 12.6 Hz, H-5 b), 2.15 (3H, s, OCOCH ),
3
2.03 (3H, s, OCOCH ).
3
0
0
(
CHCl /MeOH, 4:1). Products were extracted with CH Cl
2
3 -O-Acetyl-2 -deoxyinosine (11c). 0.094 g (94%); Non
3
2
and, after removal of the solvent, puri®ed by ¯ash chroma-
tography (CH Cl /MeOH, 95:5) to afford white solids. For
crystalline white solid. Mp 1168C. Rf0.33 (CHCl /
3
2
D
5
MeOH 9:1); [a] 222.5 (c 1, MeOH); n
(KBr) 3431,
max
2
2
2
1 1
2926, 1689, 1576 cm ; H NMR (CD OD) d 8.31 (1H, s,
time see Table 1. Alternatively, to compounds 8e or 10c
1.2 mmol) in water-saturated CHCl3 (10 ml) 1.0 g of
3
0
(
H-2), 8.06 (1H, s, H-8), 6.42 (1H, dd, J6.0, 8.7 Hz, H-1 ),
0
CAL was added. The mixture was stirred at room tempera-
ture (48 h for both 8e and 10c) affording, after usual
work-up, compounds 8b and 10b in yields comparable to
the acetone/buffer hydrolysis.
5.43 (1H, ddd, J2.0, 2.0, 6.0 Hz, H-3 ), 4.19 (1H, ddd,
0
J2.0, 3.4, 4.0 Hz, H-4 ), 3.83 (1H, dd, J3.4, 12.0 Hz,
0
0
H-5 a), 3.79 (1H, dd, J4.0, 12.0 Hz, H-5 b), 2.88 (1H,
0
.0, 14.8 Hz, H-2 b), 2.10 (3H, s, OCOCH ). Anal. Calcd
ddd, J6.0, 8.7, 14.8 Hz, H-2 a), 2.59 (1H, ddd, J2.0,
0
6
3
0
0
2
1
,3 -O-Diacetyladenosine (8b). Yield: 0.564 g (84%); Mp
for C H N O : C, 48.98; H, 4.80; N, 19.04. Found: C,
12 14 4 5
48.87; H, 4.86; N, 19.00.
2
0
25
79±1808C (from acetone) (lit. 180±1818C); [a]
D
1
49.5 (c 1, MeOH); H NMR (CDCl ) d 8.22 (1H, s,
2
3
0
0
0
H-2), 7.85 (1H, s, H-8), 6.00 (1H, d, J7.5 Hz, H-1 ),
2 -O-Acetyl-3 -deoxyinosine (11d). 0.094 g (94%); Non
0
5
5
(
.97 (1H, dd, J5.0, 7.5 Hz, H-2 ), 5.65 (1H, dd, J1.5,
crystalline white solid. Mp 1438C. Rf0.20 (CHCl /
3
0
0
25
MeOH 9:1); [a] 226.8 (c 1, MeOH); n
.0 Hz, H-3 ), 4.32 (1H, ddd, J1.5, 1.5, 1.5 Hz, H-4 ), 3.93
(KBr) 3427,
max
D
0
2.6 Hz, H-5 b), 2.12 (3H, s, OCOCH ), 1.97 (3H, s,
21 1
2925, 1689, 1586 cm ; H NMR (CD OD) d 8.34 (1H, s,
1H, dd, J1.5, 12.6 Hz, H-5 a), 3.81 (1H, dd, J1.5,
3
0
0
1
OCOCH3).
H-2), 8.03 (1H, s, H-8), 6.14 (1H, d, J2.0 Hz, H-1 ), 5.59
3
0
(1H, ddd, J2.0, 2.0, 6.7 Hz, H-2 ), 4.46 (1H, dddd, J3.3,
0
4
.0, 6.0, 10.0 Hz, H-4 ), 3.88 (1H, dd, J3.3, 12.1 Hz,
0
88%); Mp 230±2318C (from MeOH) (lit. 231±2328C);
0
0
0
2
-O-Acetyl-3 -deoxyadenosine (10b). Yield: 0.515 g
H-5 a), 3.68 (1H, dd, J4.0, 12.1 Hz, H-5 b), 2.60 (1H,
2
1
0
6.0, 14.1 Hz, H-3 b), 210 (3H, s, OCOCH ). Anal. Calcd
(
[
(
ddd, J6.7,10.0, 14.1 Hz, H-3 a), 2.18 (1H, ddd, J2.0,
2
5
1
0
for C H N O : C, 48.98; H, 4.80; N, 19.04. Found: C,
48.76; H, 4.91; N, 19.02.
a] 216.4 (c 1, MeOH); H NMR (CD OD) d 8.35
D
3
3
1H, s, H-2), 8.18 (1H, s, H-8), 6.12 (1H, d, J2.7 Hz,
1
2
14
4
5
0
0
H-1 ), 5.61 (1H, ddd, J2.7, 2.7, 6.0 Hz, H-2 ), 4.48 (1H,
0
dddd, J2.7, 3.4, 6.0, 9.4 Hz, H-4 ), 3.90 (1H, dd, J2.7,
0
0
1
2.0 Hz, H-5 a), 3.67 (1H, dd, J3.4, 12.0 Hz, H-5 b), 2.65
0
.0, 14.0 Hz, H-3 b), 2.09 (3H, s, OCOCH ).
(
1H, ddd, J6.0, 9.0, 14.0 Hz, H-3 a), 2.20 (1H, ddd, J2.7,
Acknowledgements
0
6
3
This work has been ®nancially supported by UniversitaÁ
degli Studi di Milano (Fondi ex-MURST 60%) and the
Italian National Council for Research (CNR, Target Project
on Biotechnology).
Enzymatic deaminating hydrolysis of adenosine
derivatives 5, 8b, 9b, 10b to inosine derivatives 6, 11a,
11c±d. Compounds 5, 8b, 9b and 10b (0.1 g) in water
(10 ml) were treated with ADA (10% by weight, 10 mg)
and reacted at 508C for the time indicated in Table 2.
The reactions were monitored by TLC (CHCl /MeOH,
3
References
4:1). The solution was lyophilized and the residue
crystallized as white solids (compounds 6 and 11a).
The acetates 11c and 11d resisted several attempts at
crystallization.
1. (a) Cory, J. G.; Suhadolnik, R. J. Biochemistry 1965, 4, 1729±
1732. (b) Cory, J. G.; Suhadolnik, R. J. Biochemistry 1965, 4,
1733±1735.
2
. Ford Jr., H.; Siddiqui, M. A.; Driscoll, J. S.; Marquez, V. E.;
0
3
(
4
8
-Deoxyinosine (6). Yield: 0.095 g (95%); Mp 2038C
Kelley, J. A.; Mitsuya, H.; Shirasaka, T. J. Med. Chem. 1995, 38,
1189±1195 and references cited herein.
6
from MeOH) (lit. 197±1998C). Rf0.20 (CHCl /MeOH
3
2
5
1
:1); [a] 242.3 (c 1, H O); H NMR (DMSO-d ) d
3. Ciuffreda, P.; Casati, S.; Santaniello, E. Bioorg. Med. Chem.
Lett. 1999, 9, 1577±1582.
4. In a different synthetic approach, we started from inosine 2 and
D
2
6
.31 (1H, s, H-2), 8.04 (1H, s, H-8), 5.85 (1H, d,
0
0
J2.0 Hz, H-1 ), 5.66 (1H, d, J3.3 Hz, 2 -OH), 4.99