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13.2 Hz), 2.57 (t, 2H, J¼7.2 Hz), 3.06 (m, 1H), 3.32 (t, 2H,
J¼6.8 Hz), 3.51 (ddd, 1H, J¼5.6, 6.0, 12.0 Hz), 3.60 (ddd,
1H, J¼5.6, 6.0, 12.0 Hz), 3.79 (ddd, 1H, J¼3.2, 5.6,
5.6 Hz), 4.39 (m, 1H), 4.87 (dd, 1H, J¼6.0, 6.0 Hz), 5.24 (d,
1H, J¼4.4 Hz), 6.25 (dd, 1H, J¼6.8, 7.6 Hz), 6.51 (s, 2H),
9.53 (br, 1H), 10.79 (s, 1H); 13C NMR (DMSO-d6,
100 MHz) d 16.2, 26.8, 36.9, 38.3, 62.0, 71.0, 71.2, 83.6,
87.6, 94.3, 115.8 (q, J¼286.0 Hz), 116.8, 129.5, 150.4, 153.6,
155.9, 156.2 (q, J¼36.0 Hz); ESI-MS m/z 445.1 [MþH]þ.
(ddd, 1H, J¼2.4, 6.4, 12.8 Hz), 2.77 (m, 2H), 2.89 (ddd, 1H,
J¼6.4, 8.0, 12.8 Hz), 3.22 (td, 2H, J¼6.4, 6.4 Hz), 3.53 (m,
1H), 3.62 (m, 1H), 3.79 (ddd, 1H, J¼3.2, 4.8, 4.8 Hz), 4.37
(m, 1H), 5.00 (dd, 1H, J¼5.2, 5.2 Hz), 5.25 (d, 1H,
J¼4.4 Hz), 6.14 (dd, 1H, J¼6.4, 8.0 Hz), 6.32 (s, 2H), 9.47
(t, 1H, J¼5.5 Hz), 10.58 (br, 1H); 13C NMR (DMSO-d6,
100 MHz) d 23.9, 26.8, 27.7, 37.6, 38.9, 61.8, 70.8, 83.1,
87.4, 115.4, 115.9 (q, J¼286.5 Hz), 147.6, 151.4, 152.7,
156.1 (q, J¼35.7 Hz), 156.2; ESI-MS m/z 435.2 [MþH]þ.
4.1.2.4. 8-[N-Trifluoroacetyl hexynylamido]-20-deoxyguano-
sine (1d). Compound 1d was prepared from 5 (200 mg,
0.578 mmol), 7d (223 mg, 1.16 mmol), Pd(PPh3)4 (66.7 mg,
0.0577 mmol), CuI (17.3 mg, 0.0908 mmol), and Et3N
(121 ml, 0.867 mmol) in dry DMF (20 ml) by the method
described for 1a. Purification by silica gel column chromatog-
raphy (CHCl3/MeOH¼10:1 to 5:1) gave 1d (237 mg,
4.1.3.3. 8-[N-Trifluoroacetyl pentylamido]-20-deoxyguanosine
(3c). Compound 3c was prepared from 1c (63.7 mg,
0.143 mmol) and 10% Pd/C (30 mg) in anhydrous methanol
(5.0 ml) by the method described for 3a. Purification by silica
gel column chromatography (CHCl3/MeOH¼5:1) gave 3c
(52.3 mg, 0.117 mmol, 82%) as a colorless powder. 1H
NMR (CD3OD, 400 MHz) d 1.41 (m, 2H), 1.61 (tt, 2H,
J¼7.3, 7.5 Hz), 1.76 (tt, 2H, J¼7.5, 7.5 Hz), 2.21 (ddd,
1H, J¼2.0, 6.1, 13.3 Hz), 2.83 (t, 2H, J¼7.5 Hz), 3.09 (ddd,
1H, J¼6.1, 8.7, 13.3 Hz), 3.27 (t, 2H, J¼7.3 Hz), 3.74 (dd, 1H,
J¼3.7, 12.1 Hz), 3.85 (dd, 1H, J¼3.1, 12.1 Hz), 4.03 (ddd, 1H,
J¼3.1, 3.7, 5.6 Hz), 4.59 (ddd, 1H, J¼2.0, 5.6, 6.1 Hz), 6.14
(dd, 1H, J¼6.1, 8.7 Hz); 13C NMR (DMSO-d6, 100 MHz)
d 25.7, 26.3, 27.2, 27.9, 37.5, 40.1, 61.8, 70.9, 83.1, 87.4,
115.4, 115.9 (q, J¼287 Hz), 147.8, 151.4, 152.7, 156.0 (q,
J¼35.6 Hz), 156.2; ESI-MS m/z 449.7 [MþH]þ.
1
0.517 mmol, 89%) as a colorless powder. H NMR (DMSO-
d6, 400 MHz) d 1.54e1.69 (complex, 4H), 2.09 (ddd, 1H,
J¼3.2, 6.4, 12.8 Hz), 2.56 (t, 2H, J¼6.8 Hz), 3.05 (ddd, 1H,
J¼6.4, 8.0, 12.8 Hz), 3.24 (dt, 2H, J¼6.1, 6.3 Hz), 3.50
(ddd, 1H, J¼6.0, 6.0, 11.2 Hz), 3.60 (ddd, 1H, J¼5.6, 5.6,
11.2 Hz), 3.79 (ddd, 1H, J¼3.2, 5.6, 6.0 Hz), 4.38 (m, 1H),
4.88 (dd, 1H, J¼5.6, 6.0 Hz), 5.24 (d, 1H, J¼4.0 Hz), 6.24
(dd, 1H, J¼6.4, 8.0 Hz), 6.49 (s, 2H), 9.47 (t, 1H,
J¼6.1 Hz), 10.77 (s, 1H); 13C NMR (DMSO-d6, 100 MHz)
d 18.1, 24.7, 27.4, 36.9, 38.5, 62.0, 71.0, 71.2, 83.6, 87.6,
94.9, 115.9 (q, J¼286.2 Hz), 116.8, 129.6, 150.5, 153.6,
155.9, 156.1 (q, J¼35.0 Hz); ESI-MS m/z 459.2 [MþH]þ.
4.1.3.4. 8-[N-Trifluoroacetyl hexylamido]-20-deoxyguanosine
(3d). Compound 3d was prepared from 1d (153 mg,
0.334 mmol) and 10% Pd/C (60 mg) in anhydrous methanol
(15 ml) by the method described for 3a. Purification by silica
gel column chromatography (CHCl3/MeOH¼5:1) gave 3d
(152.1 mg, 0.329 mmol, 99%) as a colorless powder. 1H
NMR (CD3OD, 400 MHz) d 1.33e1.47 (complex, 4H), 1.57
(tt, 2H, J¼7.1, 7.1 Hz), 1.74 (tt, 2H, J¼7.5, 7.5 Hz), 2.19 (ddd,
1H, J¼2.0, 6.1, 13.4 Hz), 2.82 (t, 2H, J¼7.5 Hz), 3.09 (ddd,
1H, J¼6.1, 8.8, 13.4 Hz), 3.26 (t, 2H, J¼7.1 Hz), 3.74 (dd, 1H,
J¼3.6, 12.1 Hz), 3.85 (dd, 1H, J¼3.1, 12.1 Hz), 4.03 (m, 1H),
4.60 (m, 1H), 6.23 (dd, 1H, J¼6.1, 8.8 Hz); 13C NMR
(DMSO-d6, 100 MHz) d 25.8, 26.7, 27.2, 28.0, 28.1, 37.5,
39.0, 61.8, 70.9, 83.1, 87.4, 115.4, 115.9 (q, J¼286.5 Hz),
147.9, 151.4, 152.7, 156.0 (q, J¼36.0 Hz), 156.2; ESI-MS m/z
463.2 [MþH]þ.
4.1.3. General procedure for hydrogenation
4.1.3.1. 8-[N-Trifluoroacetyl propylamido]-20-deoxyguanosine
(3a). Pd/C (10%, 58 mg) was added to a solution of 1a
(294 mg, 0.707 mmol) in anhydrous methanol (15 ml). Then,
the reaction mixture was stirred at room temperature for
24 h under H2 atmosphere. Thereafter, the reaction mixture
was filtered, evaporated and purified by silica gel column chro-
matography (CHCl3/MeOH¼5:1) to yield 3a (255 mg,
1
0.607 mmol, 86%) as a colorless powder. H NMR (DMSO-
d6, 400 MHz) d 1.94 (m, 2H), 2.06 (ddd, 1H, J¼2.5, 6.2,
13.0 Hz), 3.31 (t, 2H, J¼6.8 Hz), 2.70e2.95 (complex, 3H),
3.52 (m, 1H), 3.62 (m, 1H), 3.79 (ddd, 1H, J¼3.1, 3.1,
5.0 Hz), 4.36 (m, 1H), 4.98 (dd, 1H, J¼5.4, 5.4 Hz), 5.24 (d,
1H, J¼4.2 Hz), 6.14 (dd, 1H, J¼6.2, 8.4 Hz), 6.33 (s, 2H),
9.52 (t, 1H, J¼5.3 Hz), 10.60 (s, 1H); 13C NMR (DMSO-d6,
100 MHz) d 24.7, 25.6, 37.6, 38.8, 61.8, 70.5, 83.0, 87.4,
115.3, 115.9 (q, J¼286.5 Hz), 147.2, 151.5, 152.8, 156.2 (q,
J¼36.0 Hz), 156.2; ESI-MS m/z 421.2 [MþH]þ.
4.1.4. General procedure for deprotection of TFA group
4.1.4.1. 8-Butynylamino-20-deoxyguanosine (2). A solution of
1b (70.3 mg, 0.163 mmol) in 28% aq NH4OH (20 ml) was
stirred at room temperature for 17 h. Then, ammonia was
evaporated and the residue was triturated with Et2O to give
2 (37.9 mg, 0.113 mmol, 69%) as a colorless powder. 1H
NMR (DMSO-d6, 400 MHz) d 2.11 (ddd, 1H, J¼2.8, 6.8,
13.2 Hz), 2.87 (t, 1H, J¼6.8 Hz), 3.00e3.09 (complex, 3H),
3.50 (dd, 1H, J¼5.6, 11.6 Hz), 3.63 (dd, 1H, J¼5.2,
11.6 Hz), 3.80 (ddd, 1H, J¼3.2, 5.2, 5.6 Hz), 4.40 (m, 1H),
4.90 (br, 1H), 5.29 (br, 1H), 6.26 (dd, 1H, J¼6.8, 7.2 Hz),
6.61 (s, 2H), 8.53 (br, 2H); 13C NMR (DMSO-d6, 100 MHz)
4.1.3.2. 8-[N-Trifluoroacetyl butylamido]-20-deoxyguanosine
(3b). Compound 3b was prepared from 1b (813 mg,
1.89 mmol) and 10% Pd/C (200 mg) in anhydrous methanol
(40 ml) by the method described for 3a. Purification by silica
gel column chromatography (CHCl3/MeOH¼5:1) gave 3b
1
(743 mg, 1.71 mmol, 90%) as a colorless powder. H NMR
(DMSO-d6, 400 MHz) d 1.58 (m, 2H), 1.69 (m, 2H), 2.05