J.H. Cho et al. / Tetrahedron 67 (2011) 5487e5493
5491
CDCl3)
d
163.2, 154.2, 154.0, 150.4, 139.6, 134.7, 134.7, 128.9, 128.8,
(d, J¼10.8 Hz, 2H), 6.85 (br, 2H), 6.10 (dd, J¼4.8, 7.6 Hz, 1H), 6.03 (d,
J¼7.6 Hz, 1H), 5.70 (d, J¼4.8 Hz, 1H), 5.16e5.01 (m, 4H), 4.43 (s, 1H),
3.97 (d, J¼12.4 Hz, 1H), 3.83 (t, J¼12.4 Hz, 1H); 13C NMR (100 MHz,
128.7, 128.5, 103.2, 85.7, 83.0, 74.3, 70.6, 70.5, 62.8, 60.6, 26.0, 18.5,
14.35, ꢁ5.4; MS-ESIþ m/z 627 (MþHþ).
CDCl3)
d 156.4, 154.2, 153.6, 152.7, 148.3, 140.2, 134.7, 134.5, 128.8,
4.1.6. 20,30-O-Bis-benzyloxycarbonyluridine (4b). Compound 4b was
prepared using the same procedure as 4a: yield 99%; 1H NMR
(400 MHz, CDCl3)
128.7, 128.7, 128.6, 128.5, 87.7, 85.8, 76.1, 75.6, 70.6, 70.3, 62.6, 60.4,
21.1, 14.2; MS-ESIþ m/z 536 (MþHþ).
d
9.69 (s, 1H), 7.64 (d, J¼8.0 Hz,1H), 7.35e7.30 (m,
10H), 5.96 (d, J¼6.0 Hz, 1H), 5.74 (d, J¼8.0 Hz, 1H), 5.54 (dd, J¼5.2,
6.0 Hz, 1H), 5.45 (dd, J¼3.6, 5.2 Hz, 1H), 5.12e5.05 (m, 4H), 4.25 (d,
J¼2.4 Hz, 1H), 3.89 (d, J¼12.0 Hz, 1H), 3.80 (m, 1H), 3.69 (s, 1H); 13C
4.1.11. 50-O-[Phenyl-(ethoxy- -alaninyl)]phosphoryl-20,30-O-bis-benzyl-
L
oxycarbonyladenosine (5c). Compound 5c was prepared using the
same procedure as 5a: yield 92% (1:1 diastereomeric (RP/SP) mixture);
NMR (100 MHz, CDCl3)
d
163.8, 154.3, 154.0, 150.6, 141.7, 134.7,
1H NMR (400 MHz, CDCl3)
d 8.29 (s, 0.5H), 8.26 (s, 0.5H), 7.99 (s, 0.5H),
134.6, 128.8, 128.8, 128.7, 128.5, 103.3, 88.6, 83.3, 75.8, 74.4, 70.7,
7.93 (s, 0.5H), 7.34e7.19 (m, 15H), 6.25 (br, 2H), 6.19e6.17 (m, 1H),
6.02e5.93 (m, 1H), 5.72 (m, 1H), 5.13e5.03 (m, 7H), 4.54e4.37 (m,
70.5, 61.7, 39.2; MS-ESIþ m/z 513 (MþHþ).
2H), 4.14e3.96 (m, 2H),1.35e1.25 (m, 3H), 1.18 (m, 3H);
d
ꢁ158.03; 13
C
4.1.7. 50-O-[Phenyl-(ethoxy-
L
-alaninyl)]phosphoryl-20,30-O-bis-benzyl-
NMR (100 MHz, CDCl3) d 173.7, 173.6, 155.8, 154.1, 153.8, 153.3, 150.7,
oxycarbonyluridine (5b). Compound 5b was prepared using the same
149.8, 139.6, 134.6, 129.9, 128.9, 128.8, 128.7, 128.6, 125.1, 120.4, 120.3,
120.2, 85.9, 80.7, 75.8, 73.6, 70.6, 65.3, 50.4, 47.9, 21.0, 14.2; 31P
procedure as 5a: yield 98% (1:1 diastereomeric (RP/SP) mixture). 1H
NMR (400 MHz, CDCl3)
d
10.11e10.00 (m, 1H), 7.89 (d, J¼8.0 Hz,
(162 MHz, CDCl3)
d
3.23, 3.16; MS-ESIþ m/z 791 (MþHþ); HRMS-ESIþ:
0.5H), 7.46 (d, J¼8.8 Hz, 0.5H), 7.31e7.22 (m, 15H), 6.13e6.10 (m, 1H),
5.75e5.69 (m, 0.5H), 5.56e5.48 (m, 0.5H), 5.46e5.41 (m, 1H), 5.30 (t,
J¼5.6 Hz, 0.5H), 5.20 (t, J¼5.6 Hz, 0.5H), 5.14e5.04 (m, 4H), 4.48e4.32
(m, 2H), 4.23e4.08 (m, 3H), 4.08e3.96 (m, 1H), 3.85e3.76 (m, 1H),
1.34e1.33 (m, 3H), 1.26e1.18 (m, 3H); 13C NMR (100 MHz, CDCl3)
m/z calcd for C37H40N6O12P (MþHþ) 791.2435, found 791.2436.
4.1.12. 50-O-[Phenyl-(ethoxy-
L-alaninyl)]phosphoryladenosine
(6c). Compound 6c was prepared using the same procedure as 6a:
yield 94% (1:1 diastereomeric (RP/SP) mixture); 1H NMR
d
173.6, 173.4, 163.4, 153.9, 150.4, 139.8, 134.5, 129.9, 129.8, 129.6,
(400 MHz, CD3OD) d 8.25e8.16 (m, 2H), 7.31e7.28 (m, 2H),
129.6, 128.7, 128.6, 128.6, 128.4, 128.4, 128.3, 103.4, 86.9, 86.3, 83.3,
80.2, 76.0, 75.5, 74.6, 73.1, 70.4, 70.2, 65.3, 61.6, 61.4, 60.4, 53.6, 50.2,
7.20e7.11 (m, 3H), 6.02 (t, J¼4.8 Hz, 1H), 4.66e4.61 (m, 1H),
4.45e4.30 (m, 3H), 4.29e4.23 (m, 1H), 4.09e4.01 (m, 2H),
3.91e3.08 (m, 1H), 1.27e1.20 (m, 3H), 1.18e1.13 (m, 3H); 13C NMR
20.8, 14.0; 31P (162 MHz, CDCl3)
d
4.13, 4.07; MS-ESIþ m/z 768
(MþHþ); HRMS-ESIþ: m/z calcd for C36H38N3O14NaP (MþNaþ)
(100 MHz, CD3OD)
d 175.1, 157.4, 154.1, 152.2, 150.8, 141.1, 130.9,
790.2001, found 790.1997.
130.1, 126.3, 121.5, 121.5, 120.6, 90.0, 84.5, 75.5, 71.7, 67.4, 62.5,
51.7, 20.5, 14.6; 31P (162 MHz, CD3OD)
d
4.93, 4.78; MS-ESIþ m/z
4.1.8. 50-O-[Phenyl-(ethoxy-
L
-alaninyl)]phosphoryluridine (6b). To
523 (MþHþ); HRMS-ESIþ: m/z calcd for C21H27N6O8NaP (MþNaþ)
a solution of 5b (0.50 g, 0.65 mmol) in 10 mL of EtOH was added
1,4-cyclohexadiene (1.30 mL) and Pd/C (0.03 g, 10% Pd on activated
carbon) at rt. After stirring for 3 h at rt, the reaction mixture was
treated with Celite (2.0 g) and stirred for 30 min. The suspension
was filtered and washed with MeOH (15 mLꢂ3). The collected so-
lution was concentrated under reduced pressure and the residue
was purified by silica gel column chromatography (MeOH/
EtOAc¼1:10 v/v) to give 6b (0.32 g, 0.64 mmol), as a 1:1 di-
astereomeric (RP/SP) mixture, in 98% yield. 1H NMR (400 MHz,
545.1517, found 545.1515.
4.1.13. 50-O-tert-Butyldimethylsilyl-20,30-O-bis-benzyloxycarbonyl-
guanosine (3d). To a solution of guanosine (2.0 g, 7.06 mmol) in
20 mL of anhydrous DMSO was added DMAP (0.09 g, 0.71 mmol),
Et3N (1.07 g, 10.6 mmol), and TBSCl (1.17 g, 7.76 mmol) at 0 ꢀC
under N2 atmosphere. After stirring for 24 h at rt, 20 mL of an-
hydrous CH2Cl2, CbzCl (4.82 g, 28.24 mmol), and DMAP (4.32 g,
35.30 mmol) was added to the solution at 0 ꢀC under N2 atmo-
sphere. After stirring for 48 h at rt, the reaction mixture was
concentrated under reduced pressure and the residue was dis-
solved in CH2Cl2 (100 mL) and washed with cold 0.5 M HCl solu-
tion (30 mLꢂ2), cold water (30 mL), and brine (30 mL). The
organic layer was dried over Na2SO4, and filtered. The filtrate was
concentrated and purified by silica gel column chromatography
(CH2Cl2/MeOH¼30:1 to 10:1 v/v) to give 3d (4.32 g, 6.49 mmol) in
CD3OD)
d
7.70 (d, J¼8.0 Hz, 0.5H), 7.63 (d, J¼8.0 Hz, 0.5H), 7.39e7.33
(m, 2H), 7.27e7.18 (m, 3H), 5.91 (d, J¼8.8 Hz, 0.5H), 5.89 (d,
J¼8.8 Hz, 0.5H), 5.69 (d, J¼8.0 Hz, 0.5H), 5.61 (d, J¼8.0 Hz, 0.5H),
4.44e4.29 (m, 2H), 4.19e4.09 (m, 5H), 3.98e3.91 (m, 1H),
3.87e3.76 (m, 1H), 1.36e1.30 (m, 3H), 1.25e1.21 (m, 3H); 13C NMR
(100 MHz, CD3OD)
d 175.2, 166.2, 152.2, 142.4, 131.0, 130.8, 126.4,
126.2, 121.5, 103.2, 90.8, 84.0, 75.3, 71.1, 67.4, 62.5, 62.4, 51.7, 20.6,
14.6; 1P (162 MHz, CD3OD)
d
4.94, 4.76; MS-ESIþ m/z 500 (MþHþ);
92% yield. 1H NMR (400 MHz, DMSO-d6)
d 10.74 (br, 1H), 7.85 (s,
HRMS-ESIþ: m/z calcd for C20H26N3O10NaP (MþNaþ) 522.1253,
1H), 7.40e7.29 (m, 10H), 6.57 (br, 2H), 5.99 (d, J¼7.2 Hz, 1H), 5.67
(dd, J¼5.2, 7.2 Hz, 1H), 5.40 (dd, J¼2.8, 5.2 Hz, 1H), 5.18e5.10 (m,
4H), 4.30 (q, J¼3.6 Hz, 1H), 3.87 (d, J¼3.6 Hz, 2H), 0.89 (s, 9H), 0.09
found 522.1256.
4.1.9. 50-O-tert-Butyldimethylsilyl-20,30-O-bis-benzylox-
ycarbonyladenosine (3c). Compound 3c was prepared using the
same procedure as 3a: yield 92% (two steps); 1H NMR (400 MHz,
(3H), 0.08 (s, 3H); 13C NMR (100 MHz, DMSO-d6)
d 173.7, 156.6,
154.1, 153.5, 153.1, 151.3, 135.0, 134.8, 134.3, 128.7, 128.6, 128.5,
128.4, 128.2, 116.4, 82.9, 82.4, 76.1, 74.6, 69.9, 69.7, 62.8, 47.3, 33.9,
25.8, 25.5, 18.0, ꢁ5.5, ꢁ5.6; MS-ESIþ m/z 666 (MþHþ); HRMS-
ESIþ: m/z calcd for C32H40N5O9Si (MþHþ) 666.2601, found
666.2603.
CDCl3)
d 8.33 (s, 1H), 8.15 (s, 1H), 7.37e7.29 (m, 10H), 6.33 (d,
J¼6.4 Hz, 1H), 5.81 (dd, J¼4.8, 6.0 Hz, 1H), 5.66 (br, 2H), 5.52 (dd,
J¼4.8, 6.0 Hz, 1H), 5.17e5.05 (m, 4H), 4.37 (q, J¼2.8 Hz, 1H), 3.95
(dd, J¼2.8, 11.6 Hz, 1H), 3.80 (dd, J¼2.8, 11.6 Hz, 1H), 0.94 (s, 9H),
0.13 (s, 6H); 13C NMR (100 MHz, CDCl3)
d
155.6, 154.4, 153.9, 153.6,
4.1.14. 20,30-O-Bis-benzyloxycarbonylguanosine (4d). Compound 4d
150.3, 142.8, 138.9, 134.8, 134.7, 128.9, 128.9, 128.9, 128.8, 128.6,
120.0, 85.0, 83.3, 77.0, 74.7, 70.6, 70.5, 62.9, 26.1, ꢁ5.2, ꢁ5.3; MS-
ESIþ m/z 650 (MþHþ).
was prepared using the same procedure as 4a: yield 92%; 1H NMR
(400 MHz, DMSO-d6)
d 10.72 (br, 1H), 7.99 (s, 1H), 7.38e7.29 (m,
10H), 6.55 (br, 2H), 5.98 (d, J¼7.6 Hz, 1H), 5.72 (dd, J¼5.2, 7.6 Hz,
1H), 5.47 (t, J¼5.2 Hz,1H), 5.42 (dd, J¼2.0, 5.2 Hz,1H), 5.17e5.06 (m,
5H), 4.26 (q, J¼2.0 Hz,1H), 3.68 (m, 2H); 13C NMR (100 MHz, DMSO-
4.1.10. 20,30-Bis-benzyloxycarbonyladenosine (4c). Compound 4c
was prepared using the same procedure as 4a: yield 98%; 1H NMR
d6) d 186.5, 175.4, 173.7, 156.6, 154.0, 153.6, 153.1, 151.2, 135.2, 135.0,
(400 MHz, CDCl3)
d
8.25 (s,1H), 7.71 (s,1H), 7.36e7.27 (m,10H), 7.00
134.9, 128.6, 128.6, 128. 5, 128.5, 128.4, 128.2, 116.5, 83.1, 83.1, 76.1,