5086 J . Org. Chem., Vol. 65, No. 17, 2000
Hwu et al.
eluant) to afford 20a (256 mg, 0.250 mmol) in 91% yield: mp
126-128 °C (EtOAc/hexanes, lit.26 mp 121-127 °C); Rf ) 0.13
(s, 1 H), 8.61 (s, 1 H), 8.80 (s, 1 H). Its spectroscopic
characteristics are consistent with those of the same compound
reported.30
1
(EtOAc); H NMR (CDCl3) δ 0.13 (s, 6 H), 0.15 (s, 6 H), 0.19
Meth od II. The standard procedure was followed by use of
21 (414 mg, 0.529 mmol, 1.0 equiv), CAN-SiO2 (290 mg,
containing 29.0 mg of CAN, 0.0520 mmol, 0.10 equiv), and CH2-
Cl2 (8.0 mL). After the reaction mixture was stirred for 0.10
h, it was worked up and the residue was purified by column
chromatography (20% MeOH in CHCl3 as eluant) to afford 22
(230 mg, 0.450 mmol) in 85% yield.
(s, 6 H), 0.92 (s, 9 H), 1.02 (s, 18 H), 2.50 (br s, 1 H), 3.58-
3.96 (m, 4 H), 3.98-4.36 (m, 4 H), 4.45-4.49 (m, 2 H), 4.53 (d,
J ) 12 Hz, 2 H), 5.71 (d, J ) 8.0 Hz, 2 H), 5.76 (d, J ) 4.0 Hz,
1 H), 5.78 (d, J ) 4.0 Hz, 1 H), 7.54 (d, J ) 8.0 Hz, 1 H), 7.58
(d, J ) 8.0 Hz, 1 H), 8.40 (br s, 1 H), 8.60 (br s, 1 H). Its
spectroscopic characteristics are consistent with those of the
same compound reported.26
1-O-Ben zoylglycer ol (24): Meth od I. The standard pro-
cedure was followed by use of 1-O-benzoyl-3-O-(triphenyl-
methyl)glycerol (23, 727 mg, 1.66 mmol, 1.0 equiv), CAN (91.0
mg, 0.165 mmol, 0.10 equiv), and MeCN (10 mL). After the
reaction mixture was stirred for 9.0 h, it was concentrated
under reduced pressure and the residue was purified by
column chromatography (Et2O as eluant) to afford 24 (305 mg,
1.56 mmol) as an oil in 94% yield: Rf ) 0.46 (ether); 1H NMR
(CDCl3) δ -2.45 (br s, 1 H), 3.59-3.74 (m, 2 H), 3.95 (d, J )
6.2 Hz, 1 H), 4.00-4.23 (m, 1 H), 4.36-4.40 (m, 2 H), 7.36-
8.01 (m, 5 H); 13C NMR (CDCl3) δ 63.42, 65.79, 70.39, 128.48,
129.74, 133.36, 166.99. Its spectroscopic characteristics are
consistent with those of the same compound reported.8
Meth od II. The standard procedure was followed by use of
23 (648 mg, 1.48 mmol, 1.0 equiv), CAN-SiO2 (812 mg,
containing 81.2 mg of CAN, 0.148 mmol, 0.10 equiv), and CH2-
Cl2 (8.0 mL). After the reaction mixture was stirred for 45 min,
it was worked up and the residue was purified by chromatog-
raphy on silica gel (Et2O as eluant) to afford 24 (284 mg, 1.45
mmol) as an oil in 98% yield.
Sta n d a r d P r oced u r e for Desilyla tion by Use of Cer ic
Am m on iu m Nitr a te (Meth od III). A solution of a silylated
compound (1.0 equiv) in 2-propanol (10 mL/mmol) was treated
with CAN (0.85 equiv). It was stirred at 25 °C until no starting
material was left as shown by TLC. The reaction mixture was
concentrated under reduced pressure and the residue was
purified by use of gravity column chromatography packed with
silica gel to provide the desired product with purity >99.9%.
Sta n d a r d P r oced u r e for Desilyla tion by Use of Cer ic
Am m on iu m Nitr a te Ad sor bed on Silica Gel (Meth od IV).
A solution of a silylated compound (1.0 equiv) in a mixture of
2-propanol and CCl4 (1:1, 10 mL/mmol) was treated with
CAN-SiO2 (containing 0.45 equiv of CAN). It was heated at
reflux until no starting material was left as shown by TLC.
The reaction mixture was concentrated under reduced pres-
sure and the residue was purified by use of gravity column
chromatography packed with silica gel to provide the desired
product with purity >99.9%.
2′-O-(ter t-Bu tyld im eth ylsilyl)a d en osin e (28a ). Meth od
III. The standard procedure was followed by use of 27a (98.5
mg, 0.199 mmol, 1.0 equiv), CAN (92.7 mg, 0.169 mmol, 0.85
equiv), and 2-PrOH (2.0 mL). After the reaction mixture was
stirred for 26 h, it was worked up and the residue was purified
by use of column chromatography (EtOAc as the eluant) to
afford 28a (65.9 mg, 0.173 mmol) as white solids in 87% yield.
Its physical properties and spectroscopic characteristics are
consistent with those of the same compound reported.26
Meth od IV. The standard procedure was followed by use
of 27a (131 mg, 0.264 mmol, 1.0 equiv), CAN-SiO2 (130 mg,
containing 65.1 mg of CAN, 0.119 mmol, 0.45 equiv), and
2-PrOH/CCl4 (1:1, 2.7 mL). After the reaction mixture was
stirred for 7.0 h, it was worked up and the residue was purified
by use of column chromatography (EtOAc as the eluant) to
afford 28a (90.7 mg, 0.238 mmol) as white solids in 90% yield.
3′-O-(ter t-Bu tyld im eth ylsilyl)a d en osin e (28b). Meth od
III. The standard procedure was followed by use of 27b (101
mg, 0.204 mmol, 1.0 equiv), CAN (94.9 mg, 0.173 mmol, 0.85
equiv), and 2-PrOH (2.0 mL). After the reaction mixture was
stirred for 24 h, it was worked up and the residue was purified
by use of column chromatography (EtOAc as the eluant) to
afford 28b (66.2 mg, 0.173 mmol) as white solids in 85% yield.
Its physical properties and spectroscopic characteristics are
consistent with those of the same compound reported.26
Meth od IV. The standard procedure was followed by use
of 27b (179 mg, 0.361 mmol, 1.0 equiv), CAN-SiO2 (178 mg,
Meth od II. The standard procedure was followed by use of
19a (296 mg, 0.228 mmol, 1.0 equiv), CAN-SiO2 (125 mg,
containing 12.5 mg of CAN, 0.0230 mmol, 0.10 equiv), and CH2-
Cl2 (8.0 mL). After the reaction mixture was stirred for 0.10
h, it was worked up and the residue was purified by column
chromatography (10% MeOH in EtOAc as eluant) to afford 20a
(210 mg, 0.205 mmol) in 90% yield.
Tr ich lor oeth yl 3′-[2′-O-(ter t-Bu tyld im eth ylsilyl)u r id yl]
5′-[2′,3′-O-(Isopr opyliden e)u r idyl] P h osph ate (20b): Meth -
od I. The standard procedure was followed by use of trichlo-
roethyl 3′-[2′-O-(tert-butyldimethylsilyl)-5′-O-(p-methoxyphe-
nyldiphenylmethyl)uridyl] 5′-[2′,3′-O-(isopropylidene)uridyl]
phosphate (19b, 524 mg, 0.473 mmol, 1.0 equiv), CAN (26.0
mg, 0.0479 mmol, 0.10 equiv), and MeCN (10 mL). After the
reaction mixture was stirred for 1.0 h, it was concentrated un-
der reduced pressure and the residue was purified by column
chromatography (10% MeOH in EtOAc) to afford 20b (319 mg,
0.382 mmol) in 80% yield: mp 134-135 °C (EtOAc/hexanes);
Rf ) 0.10 (EtOAc); 1H NMR (CDCl3) δ 0.17 (br s, 6 H), 0.99 (s,
9 H), 1.33 (s, 3 H), 1.52 (s, 3 H), 2.35 (br s, 1 H), 3.57-3.97 (m,
4 H), 3.98-4.38 (m, 4 H), 4.44-4.53 (m, 2 H), 4.56 (d, J ) 12
Hz, 2 H), 5.60 (d, J ) 8.0 Hz, 1 H), 5.82 (d, J ) 8.0 Hz, 1 H),
5.80 (d, J ) 4.0 Hz, 1 H), 5.93 (d, J ) 4.0 Hz, 1 H), 7.60 (d, J
) 8.0 Hz, 1 H), 7.72 (d, J ) 8.0 Hz, 1 H), 8.48 (br s, 1 H), 8.90
(br s, 1 H). Anal. Calcd for C29H42Cl3N4O14PSi: C, 41.66; H,
5.06; N, 6.70. Found: C, 41.48; H, 4.98; N, 6.82.
Meth od II. The standard procedure was followed by use of
19b (314 mg, 0.283 mmol, 1.0 equiv), CAN-SiO2 (155 mg,
containing 15.5 mg of CAN, 0.0280 mmol, 0.10 equiv), and CH2-
Cl2 (8.0 mL). After the reaction mixture was stirred for 0.10
h, it was worked up and the residue was purified by column
chromatography (10% MeOH in EtOAc as eluant) to afford 20b
(213 mg, 0.255 mmol) in 90% yield.
Tr ich lor oeth yl 3′-[2′-O-(ter t-Bu tyld im eth ylsilyl)u r id yl]
5′-Ur id yl P h osp h a t e (20c): Met h od II. The standard
procedure was followed by use of 19b (350 mg, 0.316 mmol,
1.0 equiv), CAN-SiO2 (174 mg, containing 17.4 mg of CAN,
0.0318 mmol, 0.10 equiv), and CH2Cl2 (8.0 mL). After the
reaction mixture was stirred for 2.0 h, it was worked up and
the residue was purified by column chromatography (10%
MeOH in EtOAc as eluant) to afford 20c (220 mg, 0.277 mmol)
as solids in 88% yield: mp 161-163 °C (EtOAc/hexanes); Rf )
0.040 (EtOAc); 1H NMR (DMSO-d6) δ 0.10 (br s, 6 H), 1.20 (s,
9 H), 2.30-2.50 (br, 3 H), 3.49-3.88 (m, 4 H), 3.89-4.32 (m,
4 H), 5.25-5.38 (m, 2 H), 4.56 (d, J ) 11 Hz, 2 H), 5.62 (d, J
) 7.5 Hz, 1 H), 5.81 (d, J ) 7.5 Hz, 1 H), 5.81 (d, J ) 4.0 Hz,
1 H), 5.92 (d, J ) 4.0 Hz, 1 H), 7.80 (d, J ) 7.5 Hz, 1 H), 7.98
(d, J ) 7.5 Hz, 1 H), 11.20 (br s, 2 H). Anal. Calcd for C26H38
-
Cl3N4O14PSi: C, 39.23; H, 4.81; N, 7.04. Found: C, 39.44; H,
4.75; N 7.12.
2-[1-(Ad en in -9-yl)m et h oxy]et h yl 2-(Ad en in -9-yl)-2-(2-
h yd r oxyeth oxy)eth yl P h osp h a te (22): Meth od I. The
standard procedure was followed by use of 2-[1-(adenin-9-yl)-
methoxy]ethyl 2-(adenin-9-yl)-2-[2-(p-methoxyphenyldiphenyl-
methyl)ethoxy]ethyl phosphate (21, 378 mg, 0.483 mmol, 1.0
equiv), CAN (26.3 mg, 0.0480 mmol, 0.10 equiv), and MeCN
(10.0 mL). After the reaction mixture was stirred for 1.0 h, it
was concentrated under reduced pressure and the residue was
purified by column chromatography (20% MeOH in CHCl3 as
eluant) and followed by recrystallization with EtOH to afford
22 (192 mg, 0.376 mmol) in 78% yield: mp >250 °C dec; Rf )
1
0.49 (i-PrOH/NH4OH/H2O ) 7:1:2); H NMR (DMSO-d6/D2O)
δ 3.70-4.14 (m, 10 H), 5.48-5.68 (m, 3 H), 7.98 (s, 1 H), 8.17