An efficient synthesis of cyclic IDP- and cyclic 8-bromo-IDP-carbocyclic-riboses using a modified hata condensation method to form an intramolecular pyrophosphate linkage as a key step. An entry to a general method for the chemical synthesis of cyclic ADP-ribose analogues

Article abstract of DOI:10.1021/jo0000877

An efficient synthesis of cyclic IDP-carbocyclic-ribose (3) and its 8-bromo derivative 6, as stable mimics of cyclic ADP-ribose, was achieved, and a condensation reaction with phenylthiophosphate type substrate 15 or 16 to form an intramolecular pyrophosphate linkage was a key step. N-1-Carbocyclic-ribosylinosine derivative 28 and the corresponding 8-bromo congener 24 were prepared via condensation between N-1-(2,4-dinitrophenyl)inosine derivative 17 and a known optically active carbocyclic amine 18. Compounds 24 and 28 were then converted to the corresponding 5'-phosphoryl-5'-phenylthiophosphate derivatives 15 and 16, respectively, which were substrates for the condensation reaction to form an intramolecular pyrophosphate linkage. Treatment of 8-bromo substrate 15 with I₂ or AgNO₃ in the presence of molecular sieves 3A (MS 3A) in pyridine at room temperature gave the desired cyclic product 12 quantitatively, while the yield was quite low without MS. The similar reaction of 8-unsubstituted substrate 16 gave the corresponding cyclized product 32 in 81% yield. Acidic treatment of these cyclic pyrophosphates 12 and 32 readily gave the targets 6 and 3, respectively. This result suggests that the construction of N-1-substituted hypoxanthine nucleoside structures from N-1-(2,4-dinitrophenyl)inosine derivatives and the intramolecular condensation by activation of the phenylthiophosphate group with I₂ or AgNO₃/MS 3A combine to provide a very efficient route for the synthesis of analogues of cyclic ADP-ribose such as 3 and 6. Thus, this may be an entry to a general method for synthesizing biologically important cyclic nucleotides of this type.

Full text of DOI:10.1021/jo0000877

5238
J . Org. Chem. 2000, 65, 5238-5248
An Efficien t Syn th esis of Cyclic IDP - a n d Cyclic
8-Br om o-IDP -Ca r bocyclic-Riboses Usin g a Mod ified Ha ta
Con d en sa tion Meth od To F or m a n In tr a m olecu la r P yr op h osp h a te
Lin k a ge a s a Key Step . An En tr y to a Gen er a l Meth od for th e
Ch em ica l Syn th esis of Cyclic ADP -Ribose An a logu es1
Masayoshi Fukuoka, Satoshi Shuto,* Noriaki Minakawa, Yoshihito Ueno, and Akira Matsuda
Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku,
Sapporo 060-0812, J apan
Received J anuary 21, 2000
An efficient synthesis of cyclic IDP-carbocyclic-ribose (3) and its 8-bromo derivative 6, as stable
mimics of cyclic ADP-ribose, was achieved, and a condensation reaction with phenylthiophosphate-
type substrate 15 or 16 to form an intramolecular pyrophosphate linkage was a key step. N-1-
Carbocyclic-ribosylinosine derivative 28 and the corresponding 8-bromo congener 24 were prepared
via condensation between N-1-(2,4-dinitrophenyl)inosine derivative 17 and a known optically active
carbocyclic amine 18. Compounds 24 and 28 were then converted to the corresponding 5′′-
phosphoryl-5′-phenylthiophosphate derivatives 15 and 16, respectively, which were substrates for
the condensation reaction to form an intramolecular pyrophosphate linkage. Treatment of 8-bromo
substrate 15 with I2 or AgNO3 in the presence of molecular sieves 3A (MS 3A) in pyridine at room
temperature gave the desired cyclic product 12 quantitatively, while the yield was quite low without
MS. The similar reaction of 8-unsubstituted substrate 16 gave the corresponding cyclized product
32 in 81% yield. Acidic treatment of these cyclic pyrophosphates 12 and 32 readily gave the targets
6 and 3, respectively. This result suggests that the construction of N-1-substituted hypoxanthine
nucleoside structures from N-1-(2,4-dinitrophenyl)inosine derivatives and the intramolecular
condensation by activation of the phenylthiophosphate group with I2 or AgNO3/MS 3A combine to
provide a very efficient route for the synthesis of analogues of cyclic ADP-ribose such as 3 and 6.
Thus, this may be an entry to a general method for synthesizing biologically important cyclic
nucleotides of this type.
In tr od u ction
nitrogen of the purine ring: e.g., the product of the
enzymatic reaction of an inosine or guanosine analogue
of NAD+ is not the desired N-1-cyclized product, but
rather the N-7-cyclized product.4g Accordingly, the de-
velopment of flexible methods for synthesizing cADPR
and a variety of its analogues is needed.
Cyclic ADP-ribose (cADPR, 1; Figure 1)2 is a newly
discovered general mediator involved in Ca2+ signaling.3
The synthesis of cADPR analogues has been extensively
studied by enzymatic and chemoenzymatic methods
using ADP-ribosylcyclase, due to their biological impor-
tance.4 ADP-ribosylcyclase from Aplysia california medi-
ates the intramolecular ribosylation of NAD+ and some
modified NAD+, which are prepared chemically or enzy-
matically, at the N-1-position of the purine moiety to yield
cADPR or the corresponding analogues.4 However, the
analogues that can be obtained by this method are
limited due to the substrate specificity of the enzyme.
Furthermore, even though ADP-ribosylcyclase catalyzes
the cyclization of NAD+ analogues, in some cases the
newly formed glycosidic bond is attached to the N-7
In cells, cADPR is synthesized from NAD+ by ADP-
ribosylcyclase and acts as a second messenger; it is
hydrolyzed promptly by cADPR hydrolase to give ADP-
ribose and inactivated under physiological conditions.3
cADPR is also known to be readily hydrolyzed nonenzy-
matically at the unstable N-1-glycosidic linkage of its
(4) (a) Walseth, T. F.; Lee, H. C. Biochim. Biophys. Acta 1993, 1178,
235-242. (b) Lee, H. C.; Aarhus, R.; Walseth, T. F. Science 1993, 261,
352-355. (c) Graeff, R. M.; Walseth, T. J .; Fryxell, K.; Branton, W. D.;
Lee, H. C. J . Biol. Chem. 1994, 269, 30260-30267. (d) Zhang, F.-J .;
Sih, C. J . Bioorg. Med. Chem. Lett. 1995, 5, 1701-1706. (e) Zhang,
F.-J .; Gu, Q.-M.; J ing, P. C.; Sih, C. J . Bioorg. Med. Chem. Lett. 1995,
5, 2267-2272. (f) Zhang, F.-J .; Yamada, S.; Gu, Q.-M.; Sih, C. J . Bioorg.
Med. Chem. Lett. 1996, 6, 1203-1208. (g) Zhang, F.-J .; Sih, C. J .
Tetrahedron Lett. 1995, 63, 9289-9292. (h) Zhang, F.-J .; Sih, C. J .
Bioorg. Med. Chem. Lett. 1996, 6, 2311-2316. (i) Ashamu, G. A.;
Galione, A.; Potter, B. V. L. J . Chem. Soc., Chem. Commun. 1995,
1359-1356. (j) Bailey, B. C.; Fortt, S. M.; Summerhill, R. J .; Galione,
A.; Potter, B. V. L. FEBS Lett. 1996, 379, 227-230. (k) Bailey, V. C.;
Sethi, J . K.; Fortt, S. M.; Galione, A.; Potter, B. V. L. Chem. Biol. 1997,
4, 51-60. (l) Bailey, V. C.; Sethi, J . K.; Galione, A.; Potter, B. V. L. J .
Chem. Soc., Chem. Commun. 1997, 695-696. (m) Sethi, J . K.; Empson,
R. M.; Bailey, V. C.; Potter, B. V. L. Galione, A. J . Biol. Chem. 1997,
272, 16358-16363. (n) Ashamu, G. A.; Sethi, J . K.; Galione, A.; Potter,
B. V. L. Biochemistry 1997, 36, 9509-9517. (o) Zhang, F.-J .; Gu, Q.-
M.; Sih, C. J . Bioorg. Med. Chem. 1999, 7, 653-664. (p) Wong, L.;
Aarhus, R.; Lee, H. C.; Walseth, T. F. Biochim. Biophys. Acta 1999,
1472, 555-564.
* To whom correspondence should be addressed. Phone: +81-11-
706-3229. Fax: +81-11-706-4980. E-mail: shu@pharm.hokudai.ac.jp.
(1) This paper constitutes part 195 of Nucleosides and Nucleotides.
Part 194: Abe, H.; Shuto, S.; Matsuda, A. Tetrahedron Lett. 2000, 41,
2391-2394.
(2) Clapper, D. L.; Walseth, T. F.; Dargie, P. J .; Lee, H. C. J . Biol.
Chem. 1987, 262, 9561-9568.
(3) (a) Galione, A. Science 1993, 259, 325-326. (b) Lee, H. C.;
Galione A.; Walseth, T. F. Vitam. Horm. (San Diego) 1994, 48, 199-
257. (c) Dousa, T. P.; Chini, E. N.; Beers, K. W. Am. J . Physiol. 1996,
271, C1007-C1024. (d) Lee H. C. Physiol. Rev. 1997, 77, 1133-1164.
(e) Lee, H. C. Cell Biochem. Biophys. 1998, 28, 1-17. (f) Galione, A.;
Cui, Y.; Empson, R.; Iino, S.; Wilson, H.; Terrar, D. Cell Biochem.
Biophys. 1998, 28, 19-30. (g) Guse, A. H. Cell Signalling 1999, 11,
309-316.
10.1021/jo0000877 CCC: $19.00 © 2000 American Chemical Society
Published on Web 07/26/2000

Cyclic IDP- and 8-Bromo-IDP-Carbocyclic-Ribose
J . Org. Chem., Vol. 65, No. 17, 2000 5239
reaction9 with phenylthiophosphate-type substrates to
form the intramolecular pyrophosphate linkage as a key
step, and this may be an entry to a general synthetic
method for cADPR-related compounds.10
Resu lts a n d Discu ssion
P r oblem s w ith Ou r P r eviou s Syn th esis of cIDP -
Ca r bocyclic-Ribose. Our previous synthetic route is
summarized in Scheme 1. An SN2 reaction between the
protected 8-bromoinosine derivative 7 and carbocyclic
unit 8 provided the 8-bromo-N-1-(carbocyclic-ribosyl)ino-
sine derivative 9, which was then converted to bisphos-
phate 11. Intramolecular condensation between the two
phosphate groups of bisphosphate 11 was achieved by
treating it with 1-(3-dimethylaminopropyl)-3-ethylcar-
bodiimide hydrochloride (EDC) in N-methylpyrrolidone
(NMP), and subsequent reductive debromination and
deprotection gave 3. In this synthesis, intramolecular
condensation to form the pyrophosphate linkage was the
key step, but was very difficult. The two phosphate
moieties in the molecule are perhaps separated due to
electrostatic repulsion, which would prevent the desired
condensation reaction.4o,7,8 We found that the key in-
tramolecular condensation reaction between the two
phosphate groups of 11 proceeded only when a bromo
substituent was introduced at the 8-position of the
hypoxanthine ring of the substrate.6 It is likely that the
molecule is conformationally restricted in a syn-form
around its glycosidic linkage due to the 8-bromo sub-
stituent,11 in which case the two phosphate moieties
would be rather close to each other to facilitate the
condensation, at least to some extent.6 However, the yield
of the condensation reaction was insufficient (23%), even
when the 8-bromo substrate was used.
Other problems in the previous study were rather long
reaction steps, including an enzymatic optical resolution
to construct the optically active carbocyclic unit 8 from
cyclopentadiene, and inadequate yields in the coupling
between inosine unit 7 and carbocyclic unit 8 (44%).
Thus, the development of both an efficient condensa-
tion method for forming the intramolecular pyrophos-
phate linkage and a more straightforward method for
constructing the N-1-carbocyclic structure was needed.
Th e Syn th etic P la n in Th is Stu d y. The present plan
for the synthesis of 3 and 6 is shown in Scheme 2.
Formation of the intramolecular pyrophosphate linkage
was investigated by treating 5′-phenylthiophosphates 15
and 16 as substrates with AgNO3 or I2 as a promoter.
The N-1-carbocyclic-ribosyl structure is constructed from
N-1-(2,4-dinitrophenyl)inosine derivative 17 and optically
active carbocyclic amine 18. Compounds 17 and 18 are
readily prepared from inosine and commercially available
(1R)-(-)-azabicyclo[2.2.1]hept-5-en-3-one.7b
F igu r e 1.
adenine moiety to give ADP-ribose, even in neutral
aqueous solution.5 Although further intensive studies of
cADPR are needed because of its biological importance,
this biological as well as chemical instability of cADPR
limits studies of its physiological role, at least to some
extent. Therefore, stable analogues of cADPR that exhibit
a Ca2+-mobilizing activity in cells similar to that of
cADPR are urgently required.
We designed cyclic ADP-carbocyclic-ribose (2) and its
inosine congener 3 (cIDP-carbocyclic-ribose)6 as stable
mimics of cADPR, in which an oxygen atom in the ribose
ring of cADPR is replaced by a methylene group. The
mimics 2 and 3 should be resistant to both enzymatic
and chemical hydrolysis, since they lack the unstable
N-1-glycosidic linkage of cADPR. These analogues pre-
serve all of the functional groups of cADPR, except for
this ring oxygen, and should have a conformation similar
to that of cADPR. Therefore, we expect that these
analogues would effectively mobilize intracellular Ca2+
,
like cADPR, so that they could be used as pharmacologi-
cal tools for studying the mechanism of cADPR-modu-
lated Ca2+ signaling pathways. The 8-bromo derivatives
of cADP- and cIDP-carbocyclic-riboses (5 and 6, respec-
tively) were also our synthetic targets, since Lee and co-
workers found that cyclic 8-bromo-ADPR (4) is an an-
tagonist of cADPR.4a Therefore, 5 and/or 6 may be a
biologically and chemically stable antagonist of cADPR,
which would also be very useful in biological studies.
We previously achieved the synthesis of the inosine
congener 3,6 which is the first total synthesis of a cADPR
analogue.7 However, the overall yield was very low, and
its biological activity has not been evaluated. In this
synthesis, the intramolecular condensation to form the
pyrophosphate linkage was a key step, but was very
difficult. The difficulty of forming such an intramolecular
pyrophosphate linkage, which prevented the completion
of the synthesis of target cADPR analogues, has also been
experienced by other groups.4o,7,8 Therefore, the develop-
ment of an efficient method for forming the intramolecu-
lar pyrophosphate linkage should be very beneficial.
In this paper, we describe an efficient method for
preparing 3 and 6 using a modified Hata condensation
(9) (a) Nakagawa, I.; Kony, S.; Ohtani, S.; Hata, T. Synthesis 1980,
556-557. (b) Sekine, M.; Kamimura, T.; Hata, T. J . Chem. Soc., Perkin
Trans. 1 1985, 997-1000. (c) Sekine, M.; Nishiyama, S.; Kamimura,
T.; Osaki, Y.; Hata, T. Bull. Chem. Soc. J pn. 1985, 58, 850-860. (d)
Fukuoka, K.; Suda, F.; Suzuki, R.; Ishikawa, M.; Takaku, H.; Hata,
T. Nucleosides Nucleotides 1994, 13, 1557-1567.
(10) A preliminary account of this study has been published previ-
ously: Fukuoka, M.; Shuto, S.; Minakawa, N.; Ueno, Y.; Matsuda, A.
Tetrahedron Lett. 1999, 40, 5361-5364.
(11) Although a predominance of anti- over syn-conformers is well-
known for natural nucleosides and their analogues, introducing a bulky
substituent, such as a bromo group, into the 8-position of purine
nucleosides restricts the conformation in a syn-form, through steric
repulsion for the ribose moiety: Saenger, W. Principles of Nucleic Acid
Structure; Springer-Verlag: New York, 1983.
(5) Lee, H. C.; Aarhus, R. Biochim. Biophys. Acta 1993, 1164, 68-
74.
(6) Shuto, S.; Shirato, M.; Sumita, Y.; Ueno, Y.; Matsuda, A. J . Org.
Chem. 1998, 52, 1986-1994.
(7) Synthetic approaches to carbocyclic analogues of cADP-ribose
have been published by other groups. Although the N-1-carbocyclic
inosine and adenosine structures have been constructed, formation of
the intramolecular pyrophosphate linkage has not been achieved. (a)
Fortt, S.; Potter, B. V. L. Tetrahedron Lett. 1997, 38, 5371-5374. (b)
Hutchinson, E. J .; Taylor, B. F.; Blackburn, G. M. J . Chem. Soc., Chem.
Commun. 1997, 1859-1860.
(8) Gu, Q.-M.; Sih, C. J . J . Am. Chem. Soc. 1994, 116, 7481-7486.

5240 J . Org. Chem., Vol. 65, No. 17, 2000
Fukuoka et al.
Sch em e 1
Sch em e 2
Sch em e 3
while a cyclic dimer, 14, was obtained as a major product
(Scheme 1).12 While it is unclear why such a cyclic dimer
was produced, the reaction of 13 with AgNO3 would
proceed via intermediate A, in which the 5′′-phosphate
of the carbocyclic-ribose moiety was activated as a
metaphosphate (Figure 2).13 In this study, we designed
phenylthiophosphate-type substrate 15 (Scheme 2), which
is a regioisomer of 13, as another substrate for the
intramolecular condensation reaction. A metaphosphate
intermediate, B, where the 5′-phosphate of the ribose
moiety is activated, should be produced when 15 is
treated by a promoter such as I2 or AgNO3. On the other
hand, the condensation reaction of bisphosphate 11 with
EDC might proceed via two kinds of intermediates, A′
(the 5′′-phosphate is activated) and B′ (the 5′-phosphate
is activated). It is possible that intermediates A and B,
or A′ and B′, respectively, give different reaction prod-
ucts. The reaction of 15 with AgNO3 or I2 would make it
Hata and co-workers found that the condensation
between a phenylthiophosphate and a phosphomonoester
was effectively promoted by I2 or AgNO3 to give the
corresponding pyrophosphate compounds, as shown in
Scheme 3.9 They successfully synthesized the 5′-cap
structure of mRNA using this method.9d We previously
investigated Hata’s method to form the intramolecular
pyrophosphate linkage with phenylthiophosphate deriva-
tive 13 as a substrate in a synthetic study on cIDP-
carbocyclic-ribose.12 However, when phenylthiophosphate
derivative 13, derived from 10, was treated with AgNO3
in NMP/HMPA, the desired 12 was not obtained at all,
(13) The generation of a highly active metaphosphate intermediate
has been suggested when phenylthiophosphates are treated by a
promoter such as Ag+: see ref 9c.
(12) Shuto, S.; Shirato, M.; Sumita, Y.; Ueno, Y.; Matsuda, A.
Tetrahedron Lett. 1998, 39, 7341-7344.

Cyclic IDP- and 8-Bromo-IDP-Carbocyclic-Ribose
J . Org. Chem., Vol. 65, No. 17, 2000 5241
derivative 17 and optically active carbocyclic amine 18
by this procedure.
Syn th esis of th e cIDP -Ca r bocyclic-Ribose a n d Its
8-Br om o Con gen er . The synthesis of 3 and 6 is sum-
marized in Scheme 4. 2′,3′-O-Isopropylidene-5′-O-(mono-
methoxytrityl)inosine (19) was treated with 2,4-dinitro-
chlorobenzene and K2CO3 in DMF at 80 °C14 to give N-1-
(2,4-dinitrophenyl)inosine derivative 17 as a mixture of
rotamers at the N-1-position14 in 90% yield. Heating 17
with 10 equiv of 18, which was prepared by Blackburn’s
method,7b at 50 °C in DMF gave the ring-cleaved product
20 as a mixture of stereoisomers due to a cis/ trans
geometry at the aminomethylene position in 74% yield.15
When 1.5 equiv of 18 was used, the yield of 20 was
decreased (42%). After the 5′′-hydroxyl of 20 was pro-
tected with a TBS group, it was treated with N-bromoac-
etamide (NBA) in THF16 to give 2-bromo derivative 22.
When 22 was heated in the presence of K2CO3 at 50 °C
in DMF, the desired ring-closure product 23 was obtained
in 98% yield. Similar treatment of 20 also gave 8-unsub-
stitued inosine derivative 28 in high yield. Thus, the N-1-
carbocyclic inosine structure was efficiently constructed
from N-1-(2,4-dinitrophenyl)inosine derivative 17 and a
readily available optically active carbocyclic amine, 18.
This method is clearly superior to our previous method
using SN2-type condensation between an inosine deriva-
tive and an optically active carbocyclic unit.
The TBS group of 23 was removed with TBAF in THF,
and a di(anilino)phosphoryl group was then introduced
at the resulting 5′′-primary hydroxyl by treating it with
(PhNH)2POCl17 and tetrazole in pyridine18 to give 25 in
high yield. After the 5′-O-MMTr group of 25 was removed
with aqueous AcOH, a bis(phenylthio)phosphoryl group
was introduced at the primary hydroxyl of the ribose
moiety with a cyclohexylammonium S,S-diphenylphos-
phorodithioate (PSS)/2,4,6-triisopropylbenzenesulfonyl
chloride (TPSCl)/tetrazole/pyridine system19 to give pro-
tected bisphosphate derivative 27. Successive treatment
of 27 with isoamyl nitrite in a mixed solvent of pyridine-
AcOH-Ac2O and H3PO2 in pyridine20 gave 15, the
substrate for the intramolecular condensation reaction,
in 88% yield as a triethylammonium salt. In a similar
manner, the corresponding 8-unsubstituted substrate 16
was synthesized from 28.
The intramolecular condensation reaction of 15 was
investigated under various conditions, and the results are
summarized in Table 1. HPLC charts of several reactions
are also shown in Figure 3. Reactions were carried out
by adding a solution of 15 slowly over 15 h, using a
syringe pump, to a large excess of a promoter at room
temperature, and monitored by HPLC. AgNO3 or I2 and
N-methylpyrrolidone (NMP)/hexamethylphosphoramide
(HMPA) or pyridine9 were used as a promoter and a
solvent, respectively. First, 15 was treated with AgNO3
in NMP/HMPA to give the desired 12 in only 6% yield,
along with cyclic dimer 14 and uncyclized hydrolysis
F igu r e 2.
clear whether intermediates A and B give different
products, since intermediate B should only be produced
when it is activated by the promoter. We also presumed
that phenylthiophosphates 13 and 15 should be superior
to bisphosphate 11 as a substrate for forming the
intramolecular pyrophosphate linkage, since the electro-
static repulsion described above would be rather de-
creased in intermediates A and B due to their metaphos-
phate structure, compared with that in phosphodiester-
type intermediates A′ and B′, and the metaphosphate-
type intermediates would be much more reactive than
the phosphodiester-type intermediates.
We also planned to examine the intramolecular con-
densation reaction with 8-unsubstituted phenylthiophos-
phate-type substrate 16 (Scheme 2) to investigate whether
the 8-bromo substitution facilitates intramolecular cy-
clization in the reaction system, which was observed
previously when bisphosphate-type substrate 11 was
condensed intramolecularly with EDC.6
On the other hand, Piccialli and co-workers recently
reported an excellent method for preparing N-1-alkyl-
inosines from N-1-(2,4-dinitrophenyl)inosine and alkyl-
amines.14 We planned to construct the N-1-carbocyclic-
ribosyl structure from N-1-(2,4-dinitrophenyl)inosine
(15) The carbocyclic amine 18 was recovered in 87% yield after the
reaction and was used repeatedly.
(16) Ivanovics, G. A.; Rousseau, R. J .; Kawana, M.; Srivastava, P.
C.; Robins, R. K. J . Org. Chem. 1974, 39, 3651-3654.
(17) Sasse, K. Methoden der Organiches Chemie; 1971; Vol. 12, No.
2, pp 444-450.
(18) Smrt, J . Tetrahedron Lett. 1973, 47, 4727-4728.
(19) Sekine, M.; Hamaoki, K.; Hata, T. Bull. Chem. Soc. J pn. 1981,
54, 3815-3827.
(20) Hata, T.; Kamimura, T.; Urakami, K.; Kohno, K.; Sekine, M.;
Kumagai, I.; Shinozaki, K.; Miura, K. Chem. Lett. 1987, 117-120.
(14) De Napoli, L.; Messere, A.; Montesrchio, D.; Piccialli, G.; Varra,
M. J . Chem. Soc., Perkin Trans. 1 1997, 2079-2082: N-1-dinitrophen-
ylinosine derivatives were obtained as a mixture of two rotamers at
the N-1-position.

5242 J . Org. Chem., Vol. 65, No. 17, 2000
Fukuoka et al.
Sch em e 4a
a
Conditions: (a) 2,4-dinitrochlorobenzene, K2CO3, DMF, 80 °C; (b) 18, DMF, 50 °C; (c) TBSCl, imidazole, rt; (d) NBA, THF, -10 °C;
(e) K2CO3, DMF, 50 °C; (f) TBAF, THF; (g) (PhNH)2POCl, tetrazole, py, rt; (h) aq 80% AcOH, rt; (i) PSS, tetrazole, TPSCl, py, rt; (j) (1)
isoamyl nitrite, Ac2O, AcOH, py, rt; (2) H3PO2, Et3N, py, rt; (k) I2, or AgNO3, MS 3A, py; (l) 60% HCO2H.
Ta ble 1. In tr a m olecu la r Con d en sa tion Rea ction s of 15a
purification by C18 column chromatography (entry 4). A
products (yield, %)b
similar reaction with AgNO3 instead of I2 in the presence
of MS 3A in pyridine also gave 12 in very high yield
(entry 5). Use of NMP/HMPA as a solvent clearly
decreased the yield of 12, and the cyclic dimer 14 was
formed (entries 6 and 7, Figure 3c).
entry
promoter
AgNO3
I2
I2
I2/MS 3A
AgNO3/MS 3A pyridine
I2/MS 3A
AgNO3/MS 3A NMP/HMPA
solvent
12
14
11
15
29
47
1
2
3
4
5
6
7
NMP/HMPA
NMP/HMPA
pyridine
6
6
34
10
5
8
pyridine
100
94
We next examined the use of 8-unsubstituted substrate
16 in the intramolecular condensation reaction to inves-
tigate whether the 8-bromo substituent at the purine
moiety facilitates intramolecular condensation to form a
pyrophosphate linkage. Thus, 16 was treated under the
same conditions as in entry 4 to give the desired cycliza-
tion product 32 in 81% isolated yield. An HPLC chart
for the reaction is shown in Figure 3d. An increase of
byproducts was observed by HPLC in the reaction of
8-unsubstitued 16 compared with that with 8-bromo
substrate 15 (Figure 3b). These results suggest that the
8-bromo group facilitates the intramolecular condensa-
tion reaction to some extent, due to conformational
restriction of the substrate in a syn-form around its
glycosyl linkage.
NMP/HMPA
49
42
10
6
trace
trace
a
To a mixture of AgNO3 (30 equiv) or I2 (20 equiv) [and MS 3A
(500 mg, entries 4-6)] in NMP/HMPA (3:1, 8.0 mL) or pyridine
(8.0 mL) was slowly added a solution of 15 (9.4 µmol) in the same
b
solvent (8.0 mL) at room temperature over 15 h. Entries 4 and
5, isolated yield; entries 1-3, 6, and 7, determined by HPLC.
product 11 in respective yields of 10% and 15% (entry
1). Compounds 12, 14, and 11 were identified by com-
parison with the authentic samples synthesized previ-
ously.6,12 Treatment of 15 with I2 instead of AgNO3 gave
a similar insufficient result (entry 2, Figure 3a). However,
when pyridine was used as a solvent, the yield of 12 was
clearly improved (34%), and hydrolysis product 11 was
obtained in 47% yield (entry 3). Therefore, we performed
the reaction in the presence of molecular sieves 3A (MS
3A) to remove water from the reaction system. Surpris-
ingly, the reaction with I2/MS 3A as a promoter gave the
desired 12 as a sole product (Figure 3b), which was
obtained quantitatively as a triethylammonium salt, after
The intramolecular condensation reaction of 13, which
is the regioisomeric substrate of 15, was also examined.
Compound 13 was readily prepared from 24 (Scheme 5).
Treatment of 13 under the best conditions (Table 1, entry
4) gave the desired cyclized product 12 in 99% isolated
yield. This clearly shows that both metaphosphate in-
termediates, i.e., 5′′-phosphate-activated A and 5′-

Cyclic IDP- and 8-Bromo-IDP-Carbocyclic-Ribose
J . Org. Chem., Vol. 65, No. 17, 2000 5243
F igu r e 3. HPLC analysis at 254 nm of the intramolecular condensation reactions of 15 (a, b, and c) and 16 (d) at 15 h: (a)
reaction with 15, entry 2 in Table 1; (b) reaction with 15, entry 4 in Table 1; (c) reaction with 15, entry 6 in Table 1; (d) reaction
with 16, the same conditions as in entry 4 in Table 1.
Sch em e 5a
Sch em e 6
a
Conditions: (a) PSS, tetrazole, TPSCl, py, rt; (b) aq 80% AcOH,
rt; (c) (PhNH)2POCl, tetrazole, py, rt; (d) (1) isoamyl nitrite, Ac2O,
AcOH, py, rt; (2) H3PO2, Et3N, py, rt; (3) aq NaHCO3; (e) I2, MS
3A, py rt.
intermediate is a pyridinium adduct which promotes the
intramolecular cyclization via salt formation with the
phosphate anion, since the use of pyridine as a solvent
was key to the success of the intramolecular condensa-
tion. An attempt to prepare cADPR or its analogues by
chemical intramolecular condensation was first reported
by Gu and Sih.8 They investigated condensation between
the two phosphate groups of N-1-phosphoribosyl-AMP
(36) with EDC, but were unsuccessful (yield <1%,
Scheme 6a).8 Later, ring closure of bisphosphate 37
through the formation of a pyrophosphate linkage was
examined by Fortt and Potter, but they also failed.7a We
phosphate-activated B, readily cyclized to form 12 in high
yield under these conditions.
It has been demonstrated that phenylthiophosphate-
type substrates are very effective for a condensation
reaction to form the intramolecular pyrophosphate link-
age. This may be because the electrostatic repulsion
between the two phosphate groups in the metaphosphate
intermediates A and B is relatively decreased, as we
expected. It may also be possible that the reactive

5244 J . Org. Chem., Vol. 65, No. 17, 2000
Fukuoka et al.
81.9, 63.9, 55.2, 27.1, 25.4, 25.2; HRMS (FAB, positive) calcd
for C33H33N4O6 581.2400 (MH+), found 581.2396; UV (MeOH)
λmax 251, sh 259 nm. Anal. Calcd for C33H32N4O6‚1/4H2O: C,
67.74; H, 5.60; N, 9.57. Found C, 67.56; H, 5.64; N, 9.86.
have also experienced the difficulty of conducting such
an intramolecular condensation to prepare carbocyclic
cADPR analogues.6 Accordingly, our finding in this study
with phenylthiophosphate-type substrates, i.e., that an
I2 or AgNO3/MS 3A system very efficiently promotes the
intramolecular condensation reaction between the phen-
ylthiophosphate and phosphate groups to provide the
desired cyclic pyrophosphate product in very high yield,
is very important.
N-1-(2,4-Din itr oph en yl)-5′-O-(m on om eth oxytr ityl)-2′,3′-
O-isop r op ylid en ein osin e (17). A mixture of 19 (11.5 g, 19.7
mmol), K2CO3 (6.8 g, 49.3 mmol), and 2,4-dinitrochlorobenzene
(10.0 g, 49.3 mmol) was stirred in DMF (200 mL) at 80 °C for
2.5 h. After the mixture was cooled to room temperature, the
insoluble materials were filtered and washed with EtOAc. The
filtrates and washings were combined and evaporated, and the
residue was partitioned between EtOAc and H2O. The organic
layer was washed with brine, dried (Na2SO4), and evaporated.
The residue was purified by column chromatography (SiO2,
60% EtOAc in hexane) to give a rotameric mixture of 17 (13.2
g, 90%) as brown solids: 1H NMR (CDCl3, 270 MHz) δ 9.03,
9.01 (each d, each 0.5 H, J ) 2.6) 8.64 (dd, 0.5 H, J ) 2.6, 8.6),
8.61 (dd, 0.5 H, J ) 2.6, 8.6), 7.95, 7.94 (each s, each 0.5 H),
7.89, 7.81 (each s, each 0.5 H), 7.67 (d, 0.5 H, J ) 8.6), 7.49 (d,
0.5 H, J ) 8.6), 7.41-6.75 (m, 14 H), 6.14 (d, 0.5 H, J ) 2.6),
6.13 (d, 0.5 H, J ) 2.6), 5.34 (dd, 0.5 H, J ) 2.6, 6.6), 5.25 (dd,
0.5 H, J ) 2.6, 5.9), 4.97 (dd, 0.5 H, J ) 3.3, 6.6), 4.93 (dd, 0.5
H, J ) 2.6, 5.9), 4.51 (m, 1 H), 3.75, 3.75 (each s, each 1.5 H),
3.44-3.32 (m, 2 H), 1.64, 1.41 (each s, each 3 H); 13C NMR
(CDCl3, 125 MHz) δ 158.5, 158.5, 155.0, 154.9, 147.9, 146.8,
154.1, 144.9, 143.9, 143.7, 139.7, 135.3, 134.9,131.8, 131.7,
130.3, 130.2, 128.8, 128.7, 128.2, 128.1, 127.8, 127.7, 126.9,124.6,
121.0, 120.9, 114.5, 114.5, 113.1, 113.0, 91.1, 91.0, 86.8, 86.6,
86.1, 85.9, 84.7, 84.5, 81.4, 81.4, 77.3, 77.0, 76.7, 63.8, 63.5,
55.1, 27.1, 27.1, 25.3, 25.3; HRMS (FAB, positive) calcd for
C39H35N6O10 747.2414 (MH+), found 747.2401; UV (MeOH) λmax
264, 253 nm. Anal. Calcd for C39H34N6O10‚1/2H2O: C, 61.98;
H, 4.67; N, 11.12. Found C, 62.23; H, 4.75; N, 10.77.
The cyclic pyrophosphates 32 and 12 were treated with
aqueous HCO2H at room temperature to give the targets
cIDP-carbocyclic-ribose (3) and cyclic 8-bromo-IDP-car-
bocyclic-ribose (6), respectively.
Finally, we investigated whether the synthesized cIDP-
carbocyclic-ribose (3) is stable in aqueous solution, as we
hypothesized. When 3 was treated in 10 mM triethylam-
monium acetate buffer (pH 7.0) at 37 °C, none of its
hydrolysis was observed by HPLC analysis after 3 days,
whereas cADPR (1) was clearly hydrolyzed (t1/2 ) 60.5
h) under the same conditions.
Con clu sion . We have developed a very efficient
method for synthesizing cyclic IDP-carbocyclic-ribose and
its 8-bromo derivative. The N-1-carbocyclic inosine struc-
ture was efficiently constructed from N-1-(2,4-dinitro-
phenyl)inosine derivative 17 and a readily available
optically active carbocyclic amine, 18. The key intramo-
lecular cyclization reaction of the phenylthiophosphate-
type substrates 13, 15, and 16 proceeded with I2 or
AgNO3/MS 3A to give the products in very high yields.
These results suggest that the construction of N-1-
substituted inosine structures from N-1-(2,4-dinitrophen-
yl)inosine derivatives and the intramolecular condensa-
tion through the activation of a phenylthiophosphate
group with I2 or AgNO3/MS 3A combined to provide a
very efficient route for synthesizing analogues of cyclic
ADP-ribose, such as 3 and 6. This method may be
applicable to the synthesis of cADPR analogues with an
adenine base, including 2. Thus, this may be an entry to
a general method for synthesizing biologically important
cyclic nucleotides of this type.
5-[[(1R,2S,3R,4R)-2,3-(Isopr opyr iden edioxy)-4-(h ydr oxy-
m e t h y l)c y c lo p e n t y l]a m in o m e t h y le n e a m in o ]-1-[5-O -
(m on om eth oxytr ityl)-2,3-O-(isop r op ylid en e)-â-D-r ibofu -
r a n osyl]im id a zole-4-(N-2,4-d in itr op h en yl)ca r boxa m id e
(20). A mixture of 17 (560 mg, 0.75 mmol) and the optically
active carbocyclic amine 18 (1.40 g, 7.5 mmol) in DMF (1.5
mL) was stirred at 50 °C for 21 h. The mixture was evaporated,
and the residue was partitioned between EtOAc and H2O. The
aqueous layer was evaporated, and the residue was coevapo-
rated with toluene (4.0 mL × 3) to give the carbocyclic amine
18 (1.22 g, 87%), which can be used repeatedly. The organic
layer was washed with brine, dried (Na2SO4), and evaporated.
The residue was purified by column chromatography (SiO2,
60% EtOAc in hexane) to give a cis/ trans mixture of 20 (520
mg, 74%) as an orange foam: 1H NMR (CDCl3, 500 MHz) δ
12.24 (s, 1 H), 9.14-9.11 (m, 2 H,), 8.72 (d, 1 H, J ) 3.8), 8.34
(m, 1 H), 7.42-6.82 (m, 15 H), 6.87 (m, 1 H), 7.37 (s, 1 H),
6.02 (d, 0.8 H), 5.90 (m, 0.2 H), 5.08 (dd, 0.8 H, J ) 2.5, 6.0),
4.98 (m, 0.2 H), 4.77 (dd, 1 H, J ) 3.1, 6.0), 4.61 (m, 2 H), 4.51
(m, 1 H), 4.40 (ddd, 1 H, J ) 3.1, 3.6, 6.0), 3.85 (dd, 1 H, J )
2.8, 10.0), 3.77 (s, 3 H), 3.68 (dd, 1 H, J ) 2.8, 10.0), 3.37 (dd,
1 H, J ) 6.0, 10.2), 3.33 (dd, 1 H, J ) 3.6, 10.2), 2.52 (m, 1 H),
2.37 (m, 1 H), 1.60, 1.45, 1.35, 1.28 (each s, each 3 H), 1.51
(m, 1 H); 13C NMR (CDCl3, 125 MHz) δ 162.6, 158.6, 155.1,
147.7, 143.9, 141.0, 140.4, 135.1, 134.7, 130.9, 130.3, 129.3,
128.3, 127.9, 127.9, 127.0, 122.3, 121.5, 118.7, 114.2, 113.2,
110.6, 90.6, 87.0, 86.8, 85.2, 84.9, 84.0, 81.3, 64.4, 64.1, 55.9,
55.2, 47.0, 32.9, 27.2, 26.9, 25.5, 24.4, 11.4; HRMS (FAB,
positive) calcd for C48H52N7O13 934.3623 (MH+), found 934.3615;
Exp er im en ta l Section
Chemical shifts are reported in parts per million downfield
from TMS (1H and 13C) or H3PO4 (31P), and J values are given
in hertz. The 1H NMR assignments described are in agreement
with COSY spectra. Thin-layer chromatography was done on
Merck coated plate 60F254. Silica gel chromatography was done
on Merck silica gel 5715. Reactions were carried out under an
argon atmosphere.
5′-O-(Mon om et h oxyt r it yl)-2′,3′-O-isop r op ylid en ein o-
sin e (19). A mixture of 2′,3′-O-isopropylideneinosine (12.9 g,
41.8 mmol) and MMTrCl (15.5 g, 50.2 mmol) in pyridine (400
mL) was stirred at room temperature for 40 h. After MeOH
(10 mL) was added, the resulting solution was stirred at room
temperature for 30 min and evaporated. The residue was
partitioned between EtOAc and H2O, and the organic layer
was washed with brine (200 mL), dried (Na2SO4), and evapo-
rated. The residue was purified by column chromatography
(SiO2, 4% MeOH in CHCl3) to give 19 (24.3 g, quant) as white
solids: 1H NMR (CDCl3, 500 MHz) δ 13.19 (br s, 1 H), 8.12 (s,
1 H), 7.91 (s, 1 H), 7.37-6.76 (m, 14 H), 6.12 (d, 1 H, J ) 2.1),
5.35 (dd, 1 H, J ) 2.1, 6.2), 4.94 (dd, 1 H, J ) 2.7, 6.2), 4.53
(ddd, 1 H, J ) 2.7, 4.4, 6.1), 3.75 (s, 3 H), 3.35 (dd, 1 H, J )
6.1, 10.2), 3.27 (dd, 1 H, J ) 4.4, 10.2), 1.63, 1.39 (each s, each
3 H); 13C NMR (CDCl3, 125 MHz) δ 159.2, 158.6, 148.2, 145.1,
143.9, 143.8, 139.3, 135.0, 130.2, 129.2, 128.3, 127.8, 127.8,
127.1, 127.0, 125.4, 114.3, 113.2, 113.1, 91.3, 86.7, 86.5, 84.5,
UV (MeOH) λmax 270, sh 286 nm. Anal. Calcd for C48H51N7O13
‚
1/2H2O: C, 61.14; H, 5.56; N, 10.40. Found C, 61.39; H, 5.78;
N, 10.10.
5-[[(1R,2S,3R,4R)-2,3-(Isop r op ylid en ed ioxy)-4-[[(ter t-
bu tyldim eth ylsilyl)oxy]m eth yl]cyclopen tyl]am in om eth yl-
en ea m in o]-1-[5-O-(m on om eth oxytr ityl)-2,3-O-(isop r op yl-
id e n e )-â-D -r ib ofu r a n osyl]im id a zole -4-(N -2,4-d in it r o-
p h en yl)ca r boxa m id e (21). A mixture of 20 (520 mg, 0.56
mmol), imidazole (114 mg, 1.67 mmol), and TBSCl (126 mg,
0.84 mmol) in DMF (2.8 mL) was stirred at room temperature
for 30 min. After MeOH (1.0 mL) was added, the solution was
stirred at room temperature for 10 min and evaporated. The

Cyclic IDP- and 8-Bromo-IDP-Carbocyclic-Ribose
J . Org. Chem., Vol. 65, No. 17, 2000 5245
residue was partitioned between EtOAc and H2O, and the
organic layer was washed with brine, dried (Na2SO4), and
evaporated. The residue was purified by column chromatog-
raphy (SiO2, 50% EtOAc in hexane) to give a cis/ trans mixture
of 21 (508 mg, 87%) as an orange foam: 1H NMR (CDCl3, 500
MHz) δ 12.28 (s, 1 H), 9.26 (m, 0.2 H), 9.23 (d, 0.8 H, J ) 9.5),
9.15 (d, 1 H, J ) 2.5), 8.74 (d, 1 H, J ) 4.0) 8.40 (dd, 1 H, J )
2.5, 9.5), 7.43-6.82 (m, 14 H), 7.37 (s, 1 H), 6.68 (dd, 1 H, J )
4.0, 7.8), 6.03 (d, 0.8 H, J ) 2.9), 6.02 (m, 0.2 H), 5.08 (dd, 0.8
H, J ) 2.9, 6.3), 4.87 (m, 0.2 H), 4.76 (dd, 1 H, J ) 3.2, 6.3),
4.61 (m, 1 H), 4.55 (m, 1 H), 4.47 (m, 1 H), 4.41 (ddd, 0.8 H,
J ) 3.2, 3.7, 6.0), 4.32 (m, 0.2 H), 3.87 (dd, 1 H, J ) 3.7, 10.2),
3.77 (s, 0.6 H), 3.77 (s, 2.4 H), 3.72 (dd, 1 H, J ) 2.8, 10.2),
3.38 (dd, 1 H, J ) 6.0, 10.2), 3.32 (dd, 1 H, J ) 3.7, 10.2), 2.55
(m, 1 H), 2.37 (m, 1 H), 1.60, 1.44, 1.35, 1.27 (each s, each 3
H), 1.54 (m, 1 H), 0.96 (s, 9 H), 0.17 (s, 6 H); 13C NMR (CDCl3,
125 MHz) δ 162.5, 158.7, 155.0, 147.6, 144.0, 143.9, 141.3,
140.4, 135.1, 134.7, 130.9, 130.4, 129.4, 128.4, 127.9, 127.9,
127.0, 122.3, 121.5, 118.9, 114.2, 113.2, 110.6, 90.6, 86.8, 86.8,
85.2, 85.0, 83.7, 81.4, 65.5, 64.1, 55.7, 55.2, 47.7, 33.0, 27.2,
27.0, 26.1, 26.1, 25.5, 24.6, 18.5, 14.2, -5.3, -5.4, -5.5; HRMS
(FAB, positive) calcd for C54H65N7O13NaSi 1070.4307 (MNa+),
found 1070.4330; UV (MeOH) λmax 271, sh 286 nm. Anal. Calcd
for C54H65N7O13Si: C, 61.87; H, 6.25; N, 9.35. Found C, 61.68;
H, 6.35; N, 9.35.
2-Br om o-5-[[(1R,2S,3R,4R)-2,3-(isop r op ylid en ed ioxy)-
4-[[(t er t -b u t yld im e t h ylsilyl)oxy]m e t h yl]cyclop e n t yl]-
a m in om eth ylen ea m in o]-1-[5-O-(m on om eth oxytr ityl)-2,3-
O-(isop r op ylid en e)-â-D-r ibofu r a n osyl]im id a zole-4-(N-2,4-
d in itr op h en yl)ca r boxa m id e (22). To a solution of 21 (1.23
g, 1.17 mmol) in THF (6.0 mL) was added NBA (194 mg, 1.36
mmol) in THF (6.0 mL) at -10 °C, and the mixture was stirred
at the same temperature for 30 min. The resulting mixture
was evaporated, and the residue was partitioned between
EtOAc and H2O. The organic layer was washed with brine,
dried (Na2SO4), and evaporated. The residue was purified by
column chromatography (SiO2, 20% EtOAc in hexane) to give
a cis/ trans mixture of 22 (1.16 g, 88%) as an orange foam: 1H
NMR (CDCl3, 500 MHz) δ 12.15 (s, 0.8 H), 12.14 (s, 0.2 H),
9.22-9.16 (m, 2 H), 8.40 (dd, 1 H, J ) 2.7, 9.5), 8.36 (d, 1 H,
J ) 4.1) 7.42-6.75 (m, 14 H), 6.80 (m, 1 H), 6.19 (d, 0.2 H,
J ) 2.5), 6.14 (d, 0.8 H, J ) 2.6), 5.54 (dd, 0.8 H, J ) 2.6, 6.8),
5.22 (dd, 0.2 H, J ) 2.5, 6.8), 4.83 (dd, 0.8 H, J ) 4.5, 6.8),
4.72 (m, 0.2 H), 4.52 (m, 1 H), 4.41 (m, 1 H), 4.34 (ddd, 0.8 H,
J ) 3.7, 4.5, 8.7), 4.32 (m, 1 H), 4.17 (m, 0.2 H), 3.85 (dd, 1 H,
J ) 3.4, 10.3), 3.74 (s, 3 H), 3.72 (dd, 1 H, J ) 2.8, 10.3), 3.47
(dd, 1 H, J ) 8.7, 9.9), 3.17 (dd, 1 H, J ) 3.7, 9.9), 2.44 (m, 1
H), 2.37 (m, 1 H), 1.59, 1.39, 1.34, 1.24 (each s, each 3 H), 1.41
(m, 1 H), 0.98 (s, 9 H), 0.18 (s, 6 H); 13C NMR (CDCl3, 125
MHz) δ 161.5, 158.5, 155.2, 150.0, 144.2, 144.2, 141.0, 140.6,
135.4, 134.8, 130.3, 129.4, 128.5, 128.4, 127.7, 127.7, 127.0,
126.8, 126.8, 122.3, 121.6, 119.5, 114.5, 113.1, 110.5, 91.3, 87.0,
86.4, 85.8, 84.1, 82.7, 81.6, 65.7, 64.8, 56.1, 55.1, 47.8, 32.7,
27.1, 26.9, 26.1, 25.3, 24.4, 18.5, 14.2, -5.4; HRMS (FAB,
positive) calcd for C54H64BrN7O13NaSi 1148.3413 (MNa+),
found 1148.3400; UV (MeOH) λmax 269, sh 285 nm. Anal. Calcd
for C54H64BrN7O13Si: C, 57.54; H, 5.72; N, 8.70. Found C,
57.53; H, 5.84; N, 8.93.
2.27 (m, 3 H, H-4′′, H-6′′), 1.62, 1.54, 1.37, 1.28 (each s, each
3 H, i-PrMe), 0.91 (s, 9 H, t-Bu), 0.08 (s, 6 H, SiMe); NOE
(CDCl3, 400 MHz) irradiated H-2, observed H-1′′ (9.7%), H-2′′
(4.5%); 13C NMR (CDCl3, 125 MHz) δ 158.5, 155.1, 147.5, 146.2,
144.3, 143.9, 135.3, 130.3, 128.5, 128.3, 127.6, 126.9, 126.8,
126.1, 125.5, 114.4, 113.1, 113.0, 91.4, 87.0, 86.3, 83.5, 82.9,
82.1, 81.0, 77.3, 77.0, 76.7, 65.0, 64.0, 63.7, 55.2, 46.7, 33.3,
31.9, 29.7, 29.6, 29.3, 29.3, 27.7, 27.2, 25.9, 25.4, 25.3, 22.6,
18.3, -5.4; HRMS (FAB, positive) calcd for C48H59BrN4NaO9Si
965.3133 (MNa+), found 965.3119; UV (MeOH) λmax 258, 252,
sh 271 nm.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r op yliden ed ioxy)-
4-(h ydr oxym eth yl)cyclopen tyl]-5′-O-(m on om eth oxytr ityl)-
2′,3′-O-isop r op ylid en ein osin e (24). A mixture of 23 (944 mg,
1.0 mmol) and TBAF (1.0 M in THF, 3.4 mL, 3.4 mmol) in
THF (3.4 mL) was stirred at room temperature for 1.5 h. The
resulting solution was evaporated, and the residue was puri-
fied by column chromatography (SiO2, 70% EtOAc in hexane)
to give 24 (748 mg, 90%) as a yellow foam: 1H NMR (CDCl3,
500 MHz) δ 7.54 (s, 1 H, H-2), 7.38-6.73 (m, 14 H, Ar-H), 6.17
(d, 1 H, H-1′, J ) 1.6), 5.46 (dd, 1 H, H-2′, J ) 1.6, 6.2), 5.03
(dd, 1 H, H-3′, J ) 3.6, 6.2), 4.94 (m, 1 H, H-2′′), 4.71 (m, 1 H,
H-3′′), 4.47 (m, 1 H, H-1′′), 4.45 (ddd, 1 H, H-4′, J ) 3.6, 4.9,
7.0), 3.82 (m, 2 H, H-5′′), 3.78 (s, 3 H, OCH3), 3.31 (dd, 1 H,
H-5′a, J ) 7.0, 9.8), 3.25 (dd, 1 H, H-5′b, J ) 4.9, 9.8), 2.40-
2.29 (m, 3 H, H-4′′, H-6′′), 1.62, 1.55, 1.37, 1.29 (each s, each
3 H, i-PrMe); NOE (CDCl3, 400 MHz) irradiated H-2, observed
H-1′′ (10.4%), H-2′′ (1.7%); 13C NMR (CDCl3, 125 MHz) δ 158.5,
155.2, 147.7, 146.4, 144.3, 144.0, 135.3, 130.3, 128.4, 127.6,
126.9, 126.4, 125.6, 114.4, 113.1, 113.0, 91.4, 86.9, 86.3, 83.4,
83.2, 82.0, 77.3, 77.0, 76.7, 66.4, 64.1, 63.9, 55.3, 46.6, 32.4,
27.7, 27.2, 25.4, 25.2, 11.4 ; HRMS (FAB, positive) calcd for
C42H45BrN4NaO9 851.2268 (MNa+), found 851.2236; UV (MeOH)
λmax 261 nm.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r op yliden ed ioxy)-
4-[[(d ia n ilin op h osp h or yl)oxy]m eth yl]cyclop en tyl]-5′-O-
(m on om eth oxytr ityl)-2′,3′-O-isop r op ylid en ein osin e (25).
A mixture of 24 (166 mg, 200 µmol), tetrazole (56 mg, 800
µmol), and dianilinophosphorochloridate (213 mg, 800 µmol)
in pyridine (2.0 mL) was stirred at room temperature for 47
h. Aqueous sodium acetate (2 M, 3.0 mL) was added, and the
resulting solution was stirred at room temperature for 1.0 h.
Water and CHCl3 were added, and the resulting mixture was
partitioned. The organic layer was washed with brine, dried
(Na2SO4), and evaporated. The residue was purified by column
chromatography (SiO2, 15% acetone in CHCl3) to give 25 (209
mg, 98%) as a yellow foam: 1H NMR (CDCl3, 500 MHz) δ 7.46
(s, 1 H), 7.37-6.73 (m, 24 H), 6.17 (d, 1 H, J ) 2.1), 6.02, 5.90
(each br s, each 1 H), 5.45 (dd, 1 H, J ) 2.1, 6.4), 5.03 (dd, 1
H, J ) 3.7, 6.4), 4.98 (m, 1 H), 4.80 (m, 1 H), 4.45 (ddd, 1 H,
J ) 3.7, 5.0, 6.8), 4.37-4.28 (m, 3 H), 3.77 (s, 3 H), 3.32 (dd,
1 H, J ) 6.8, 9.9), 3.23 (dd, 1 H, J ) 5.0, 9.9), 2.53-2.24 (m,
3 H), 1.62, 1.53, 1.37, 1.25 (each s, each 3 H); 13C NMR (CDCl3,
100 MHz) δ 158.2, 155.0, 147.6, 146.3, 144.1, 143.8, 139.4,
135.2, 130.2, 129.0, 128.2, 128.2, 127.7, 127.5, 127.0, 126.7,
126.3, 125.5, 121.7, 121.6, 117.9, 117.8, 114.3, 113.1, 113.0,
112.8, 91.3, 86.8, 86.2, 83.4, 82.8, 81.9, 81.8, 66.5, 66.1, 63.8,
55.2, 45.4, 45.3, 31.9, 29.2, 27.7, 27.2, 25.4, 25.2; 31P NMR
1
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r opylid en edioxy)-
4-[[(ter t-bu tyld im eth ylsilyl)oxy]m eth yl]cyclop en tyl]-5′-
O-(m on om eth oxytr ityl)-2′,3′-O-isopr opyliden ein osin e (23).
A mixture of 22 (1.16 g, 1.03 mmol) and K2CO3 (356 mg, 2.6
mmol) in DMF (10 mL) was stirred at 50 °C for 2.5 h. The
mixture was evaporated, and the residue was partitioned
between EtOAc and H2O. The organic layer was washed with
brine, dried (Na2SO4), and evaporated. The residue was
purified by column chromatography (SiO2, 25% EtOAc in
hexane) to give 23 (953 mg, 98%) as a yellow foam: 1H NMR
(CDCl3, 500 MHz) δ 7.56 (s, 1 H, H-2), 7.38-6.74 (m, 14 H,
Ar-H), 6.17 (d, 1 H, H-1′, J ) 1.8), 5.46 (dd, 1 H, H-2′, J ) 1.8,
6.4), 5.02 (dd, 1 H, H-3′, J ) 3.7, 6.4), 4.87 (dd, 1 H, H-2′′, J )
4.9, 6.5), 4.61-4.59 (m, 2 H, H-1′′, H-3′′), 4.46 (ddd, 1 H, H-4′,
J ) 3.7, 4.8, 7.1), 3.82 (dd, 1 H, H-5′′a, J ) 3.3, 10.0), 3.78 (s,
3 H, OCH3), 3.72 (dd, 1 H, H-5′′b, J ) 5.4, 10.0), 3.31 (dd, 1 H,
H-5′a, J ) 7.1, 9.8), 3.23 (dd, 1 H, H-5′b, J ) 4.8, 9.8), 2.31-
(CDCl3, 125 MHz, decoupled with H) δ 2.41 (s); HRMS (FAB,
positive) calcd for C54H56BrN6NaO10P 1081.2877 (MNa+), found
1081.2840; UV (MeOH) λmax 267, 262, 233 nm. Anal. Calcd for
C
54H56BrN6O10P‚1/5CHCl3: C, 60.06; H, 5.23; N, 7.75. Found
C, 60.10; H, 5.35; N, 7.69.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r op yliden ed ioxy)-
4-[[(d ia n ilin op h osp h or yl)oxy]m eth yl]cyclop en tyl]-2′,3′-
O-isop r op ylid en ein osin e (26). A solution of 25 (376 mg, 355
µmol) in 80% aqueous AcOH (10 mL) was stirred at room
temperature for 3 h. The resulting mixture was evaporated,
and the residue was purified by column chromatography (SiO2,
3% MeOH in CHCl3) to give 26 (225 mg, 80%) as a yellow
foam: 1H NMR (CDCl3, 270 MHz) δ 8.00 (s, 1 H), 7.22-6.87
(m, 10 H), 6.13 (d, 1 H, J ) 8.6), 6.08 (d, 1 H, J ) 5.3), 6.00 (d,
1 H, J ) 8.6), 5.16 (dd, 1 H, J ) 5.3, 5.9), 5.04 (dd, 1 H, J )
1.6, 5.9), 5.00 (dd, 1 H, J ) 4.3, 6.6), 4.93 (br, 1 H), 4.78 (dd,
1 H, J ) 2.0, 6.6), 4.57 (ddd, 1 H, J ) 4.3, 5.3, 5.9), 4.47 (m, 1

5246 J . Org. Chem., Vol. 65, No. 17, 2000
Fukuoka et al.
H,), 4.39-4.22 (m, 2 H), 3.96-3.74 (m, 2 H), 2.54-2.24 (m, 3
3A was filtered off with Celite and washed with H2O. To the
combined filtrate and washing was added TEAA buffer (2 M,
pH 7.0, 1.0 mL), and the resulting solution was evaporated.
The residue was partitioned between CHCl3 and H2O. The
aqueous layer was evaporated, and the residue was dissolved
in 0.1 M TEAA buffer (5.0 mL), which was applied to a C18
reversed phase column (1.1 × 11 cm). The column was
developed using a linear gradient of 0-40% CH3CN in TEAA
buffer (0.1 M, pH 7.0, 200 mL). Appropriate fractions were
evaporated under reduced pressure, and excess TEAA was
removed by C18 reversed phase column chromatography
(1.1 × 11 cm, eluted with 20% aqueous CH3CN) to give 12
(8.5 mg, 113 OD260 units, quant) as a triethylammonium salt,
the spectra data of which were in accord with those reported
previously.6
H), 1.67, 1.52, 1.39, 1.25 (each s, each 3 H); 31P NMR (CDCl3,
1
125 MHz, decoupled with H) δ 2.62 (s); HRMS (FAB, positive)
calcd for C34H40BrN6NaO9P 809.1676 (MNa+), found 809.1646;
UV (MeOH) λmax 257, 233, sh 273 nm.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r opylid en ed ioxy)-
4-[[(d ia n ilin op h osp h or yl)oxy]m eth yl]cyclop en tyl]-5′-O-
[bis(p h en ylth io)p h osp h or yl]-2′,3′-O-isop r op ylid en ein o-
sin e (27). A mixture of 26 (110 mg, 130 µmol), tetrazole (27
mg, 390 µmol), PSS (149 mg, 390 µmol), and TPSCl (79 mg,
260 µmol) in pyridine (1.3 mL) was stirred at room tempera-
ture for 40 h. After ice-cooled H2O (2.0 mL) was added, the
resulting solution was stirred at room temperature for 30 min,
and then H2O and CHCl3 were added. The resulting mixture
was partitioned, and the organic layer was washed with brine,
dried (Na2SO4), and evaporated. The residue was purified by
column chromatography (SiO2, 90% EtOAc in hexane) to give
27 (99 mg, 72%) as a yellow foam: 1H NMR (CDCl3, 500 MHz)
δ 7.85 (s, 1 H), 7.47-6.87 (m, 20 H), 6.43, 6.41 (each d, each 1
H, J ) 8.5, 8.5), 6.18 (d, 1 H, J ) 1.6), 5.45 (dd, 1 H, J ) 1.6,
6.2), 5.11 (dd, 1 H, J ) 3.5, 6.2), 5.00 (dd, 1 H, J ) 4.5, 6.3),
4.73 (m, 1 H), 4.55 (m, 1 H), 4.42-4.27 (m, 5 H), 2.48 (m, 1
H), 2.33 (m, 1 H), 2.23 (m, 1 H), 1.62, 1.50, 1.39, 1.21 (each s,
each 3 H); 13C NMR (CDCl3, 100 MHz) δ 155.2, 147.8, 147.2,
140.0, 135.3, 135.3, 135.0, 135.0, 129.7, 129.4, 129.2, 129.1,
126.1, 125.7, 125.7, 125.6, 121.8, 121.7, 118.1, 118.1, 114.7,
113.2, 91.3, 85.5, 85.4, 83.6, 83.1, 81.8, 81.2, 66.2, 66.1, 66.0,
65.9, 45.1, 32.2, 27.6, 27.2, 25.4, 25.2; 31P NMR (CDCl3, 125
MHz, decoupled with 1H) δ 2.38 (s), 50.9 (s); HRMS (FAB,
positive) calcd for C46H50BrN6O10P2S2 1051.1689 (MH+), found
1051.1690; UV (MeOH) λmax 249, 230, sh 265 nm. Anal. Calcd
for C46H49BrN6O10P2S2: C, 52.52; H, 4.70; Br, 7.60; N, 7.90; S,
6.10. Found C, 52.68; H, 5.01; Br, 7.42; N, 7.83; S, 5.71.
Typ ica l P r oced u r e B (En tr y 7). A solution of 15 (9.5 mg,
9.4 µmol, 142 OD260 units) in NMP/HMPA (3:1, 8.0 mL) was
added slowly over 15 h, using a syringe pump, to a mixture of
AgNO3 (48 mg, 280 µmol) and molecular sieves 3A (500 mg)
in the same solvent (8.0 mL) at room temperature in the dark.
The mixture was cooled with an ice bath, into which H2S for
10 min and then argon for 30 min were bubbled, and the
resulting mixture was evaporated. The insoluble materials
were removed by centrifugation, and the supernatant and
washings (NMP, 2.0 mL) were combined and partitioned
between CHCl3 and H2O. The aqueous layer was evaporated,
dissolved in water (100 mL), and applied to a DEAE-Sephadex
-
A-25 column (HCO3 form, 1.8 × 15 cm). The column was
developed using a linear gradient of 0-0.5 M TEAB buffer (0.5
M, pH 8.6, 200 mL). Appropriate fractions were evaporated
under reduced pressure, and excess TEAB was coevaporated
with H2O. The residue was dissolved in H2O (3.0 mL), and
applied to a C18 reversed phase column (1.1 × 11 cm). The
column was developed using a linear gradient of 0-40%
CH3CN in TEAA buffer (0.1 M, pH 7.0, 100 mL). Appropriate
fractions were evaporated under reduced pressure, and excess
TEAA was removed by C18 reversed phase column chroma-
tography (1.1 × 11 cm, eluted with 20% aqueous CH3CN) to
give 12 (2.5 mg, 33 OD260 units, 29%) as a triethylammonium
salt.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r op ylid en edioxy)-
4-[[(p h osp h or yl)oxy]m eth yl]cyclop en tyl]-5′-O-[(p h en yl-
th io)p h osp h or yl]-2′,3′-O-isop r op ylid en ein osin e (15). A
mixture of 27 (105 mg, 100 µmol) and isoamyl nitrite (202 µL,
1.5 mmol) in pyridine-AcOH-Ac2O (2:1:1, v/v, 3.0 mL) was
stirred at room temperature for 8 h. After the reaction mixture
was evaporated (at <30 °C), the residue was dissolved in a
mixture of H3PO2 (102 µL, 2.0 mmol), Et3N (139 µL, 1.0 mmol),
and pyridine (2.5 mL), and the resulting solution was stirred
at room temperature for 11 h. After the mixture was evapo-
rated (at <30 °C), the residue was partitioned between CHCl3
and H2O. After pyridine (5 mL) was added to the aqueous
layer, the resulting solution was evaporated (at <30 °C), and
the residue was dissolved in TEAA buffer (0.1 M, pH 7.0, 10
mL). The solution was applied to a C18 reversed phase column
(1.8 × 15 cm), and the column was developed using a linear
gradient of 0-40% CH3CN in TEAA buffer (0.1 M, pH 7.0, 400
mL). Appropriate fractions were evaporated, and excess TEAA
was removed by C18 reversed phase column chromatography
(1.8 × 13 cm, eluted with 20% aqueous CH3CN) to give 15 (89
mg, 88%) as a triethylammonium salt: 1H NMR (D2O, 500
MHz) δ 8.44 (s, 1 H, H-2), 7.24-7.09 (m, 5 H, Ar-H), 6.35 (s,
1 H, H-1′), 5.80 (d, 1 H, H-2′, J ) 6.4), 5.28 (dd, 1 H, H-3′,
J ) 2.7, 6.4), 5.07-5.01 (m, 2 H, H-1′′, H-2′′), 4.79 (m, 1 H,
H-3′′), 4.68 (m, 1 H, H-4′), 4.44 (m, 1 H, H-5′a), 4.11 (m, 1 H,
H-5′b), 3.97 (m, 2 H, H-5′′), 3.19 (q, 12 H, -CH2N, J ) 7.3),
2.51 (m, 1 H, H-4′′), 2.42 (m, 1 H, H-6′′a), 2.15 (m, 1 H, H-6′′b),
1.66, 1.60, 1.44, 1.38 (each s, each 3 H, i-PrMe), 1.27 (t, 18 H,
CH3CH2N, J ) 7.3); 13C NMR (D2O, 125 MHz) δ 159.0, 150.5,
150.2, 133.6, 133.6, 132.5, 132.5, 131.6, 130.6, 130.0, 126.8,
117.6, 117.1, 94.6, 89.8, 89.7, 86.5, 86.2, 84.2, 84.0, 68.5, 68.3,
64.8, 49.5, 47.2, 47.1, 35.7, 29.1, 28.6, 27.1, 26.9, 11.0; 31P NMR
HP LC An a lysis of th e Rea ction s. To the reaction mixture
(30 µL) was added TEAA buffer (2 M, pH 7.0, 10 µL), and the
resulting solution was evaporated. The residue was coevapo-
rated with H2O and partitioned between H2O and CHCl3. The
aqueous layer was filtered with a syringe filter (cellulose
acetate) and analyzed by HPLC [column YMS-ODS-M-80,
4.6 × 150 mm; 5-80% MeCN/0.1 M TEAA buffer (pH 7.0),
1.0 mL/min, 30 min; 254 nm]. Compounds 11, 12, and 14 were
eluted at 14.1, 14.7, and 15.8 min, respectively, which were
identified with the authentic samples synthesized previ-
ously,6,12 and a peak observed at 3.1 min was unknown
nonnucleosidic compound due to its UV spectrum.
N-1-[(1R,2S,3R,4R)-2,3-(Isop r op ylid en ed ioxy)-4-[(h y-
dr oxym eth yl)cyclopen tyl]-5′-O-(m on om eth oxytr ityl)-2′,3′-
O-isop r op ylid en ein osin e (28). Compound 28 (240 mg,
quant) was obtained from 20 (300 mg, 320 µmol) as described
for the synthesis of 23 after purification by column chroma-
tography (SiO2, 10% acetone in EtOAc): 1H NMR (CDCl3, 500
MHz) δ 7.85 (s, 1 H, H-8), 7.77 (s, 1 H, H-2), 7.38-6.76 (m, 14
H, Ar-H), 6.06 (d, 1 H, H-1′, J ) 2.5), 5.23 (dd, 1 H, H-2′, J )
2.5, 6.2), 5.04 (dd, 1 H, H-2′′, J ) 4.3, 6.6), 4.90 (dd, 1 H, H-3′,
J ) 3.0, 6.2), 4.75 (dd, 1 H, H-3′′, J ) 3.3, 6.6), 4.56 (ddd, 1 H,
H-1′′, J ) 4.3, 9.2, 9.2), 4.48 (ddd, 1 H, H-4′, J ) 3.0, 4.4, 5.9),
3.83 (m, 2 H, H-5′′), 3.79 (s, 3 H, OCH3), 3.35 (dd, 1 H, H-5′a,
J ) 5.9, 10.3), 3.30 (dd, 1 H, H-5′b, J ) 4.4, 10.3), 2.41 (m, 1
H, H-4′′), 2.35 (m, 2 H, H-6′′), 1.61, 1.55, 1.37, 1.30 (each s,
each 3 H, i-PrMe); NOE (CDCl3, 400 MHz) irradiated H-2,
observed H-1′′ (5.9%), H-2′′ (1.4%); 13C NMR (CDCl3, 125 MHz)
δ 158.6, 156.6, 146.7, 144.1, 143.9, 139.2, 135.1, 130.3, 128.3,
127.8, 127.0, 125.6, 114.5, 113.2, 113.0, 91.0, 86.7, 86.2, 84.6,
83.5, 82.5, 81.8, 66.1, 64.1, 63.9, 55.3, 46.8, 32.7, 30.9, 27.8,
27.2, 25.4, 25.3, 11.5; HRMS (FAB, positive) calcd for
1
(D2O, 125 MHz, decoupled with H) δ 1.81 (s), 17.9 (s); HRMS
(FAB, negative) calcd for C28H34BrN4O13P2S 807.0502 [(M -
H)-], found 807.0516; UV (H2O) λmax 246, sh 259, 284 nm.
Syn th esis of Cyclic 8-Br om o-IDP -Ca r bocyclic-Ribose
Dia ceton id e (12). Typ ica l P r oced u r e A (En tr y 4). A
solution of 15 (9.5 mg, 9.4 µmol, 142 OD260 units) in pyridine
(8.0 mL) was added slowly over 15 h, using a syringe pump,
to a mixture of I2 (50 mg, 190 µmol) and MS 3A (500 mg) in
pyridine (8.0 mL) at room temperature in the dark. The MS
C
42H47N4O9 751.3342 (MH+), found 751.3373; UV (MeOH) λmax
270 nm. Anal. Calcd for C42H46N4O9‚1/2H2O: C, 66.39; H, 6.23;
N, 7.37. Found C, 66.60; H, 6.36; N, 7.29.

Cyclic IDP- and 8-Bromo-IDP-Carbocyclic-Ribose
J . Org. Chem., Vol. 65, No. 17, 2000 5247
N-1-[(1R,2S,3R,4R)-2,3-(Isop r op ylid en ed ioxy)-4-[[(d i-
a n ilin op h osp h or yl)oxy]m eth yl]cyclop en tyl]-5′-O-(m on o-
m eth oxytr ityl)-2′,3′-O-isop r op ylid en ein osin e (29). Com-
pound 29 (245 mg, 85%) was obtained from 28 (220 mg, 293
µmol) as described for the synthesis of 25 after purification
by column chromatography (SiO2, 10% acetone in EtOAc): 1H
NMR (CDCl3, 270 MHz) δ 7.87 (s, 1 H), 7.71 (s, 1 H), 7.38-
6.75 (m, 24 H), 6.06 (d, 1 H, J ) 2.6), 5.91, 5.77 (each d, each
1 H, J ) 7.9), 5.22 (dd, 1 H, J ) 2.6, 6.6), 5.08 (dd, 1 H, J )
3.3, 6.6), 4.91-4.84 (m, 2 H), 4.49-4.31 (m, 4 H), 3.77 (s, 3
H), 3.33 (m, 1 H), 2.56-2.50 (m, 2 H), 2.29 (m, 1 H), 1.62, 1.54,
1.37, 1.28 (each s, each 3 H); 13C NMR (CDCl3, 100 MHz) δ
158.4, 156.4, 146.6, 146.5, 143.8, 143.6, 139.5, 139.1, 134.8,
130.2, 129.0, 129.0, 128.1, 128.1, 127.7, 127.6, 126.9, 126.8,
125.5, 121.6, 121.5, 117.9, 117.8, 114.3, 113.0, 113.0, 90.8, 86.6,
86.1, 84.5, 83.2, 81.9, 81.6,66.2, 66.1, 63.7, 55.2, 53.7, 45.5, 45.5,
32.1, 30.9, 29.2, 27.7, 27.2, 25.4, 25.2, 14.2; 31P NMR (CDCl3,
pH 7.0, 300 mL). Appropriate fractions were evaporated under
reduced pressure, and excess TEAA was removed by C18
reversed phase column chromatography (1.1 × 11 cm, 20%
aqueous CH3CN) to give pure 16 (53 mg, 65%) as a triethyl-
ammonium salt: 1H NMR (D2O, 500 MHz) δ 8.38 (s, 1 H, H-8),
8.20 (s, 1 H, H-2), 7.21-7.06 (m, 5 H, Ar-H), 6.29 (d, 1 H, H-1′,
J ) 2.0), 5.45 (dd, 1 H, H-2′, J ) 2.0, 6.1), 5.10 (dd, 1 H, H-3′,
J ) 2.0, 6.1), 5.04 (ddd, 1 H, H-1′′, J ) 1.6, 6.8, 7.6), 4.99(dd,
1 H, H-2′′, J ) 1.6, 6.9), 4.77 (dd, 1 H, H-3′′, J ) 1.9, 6.9), 4.68
(m, 1 H, H-4′), 4.27 (m, 1 H, H-5′a), 4.12 (m, 1 H, H-5′b), 3.98
(m, 2 H, H-5′′), 3.19 (q, 12 H, -CH2N, J ) 7.3), 2.51 (m, 1 H,
H-4′′), 2.39 (m, 1 H, H-6′′a), 2.16 (m, 1 H, H-6′′b), 1.64, 1.58,
1.42, 1.235 (each s, each 3 H, i-PrMe), 1.27 (t, 18 H, CH3CH2N,
J ) 7.3); 13C NMR (D2O, 125 MHz) δ 160.2, 150.1, 149.9, 134.9,
131.6, 130.2, 125.9, 117.5, 117.0, 93.3, 88.8, 86.6, 84.3, 76.2,
75.0, 68.2, 68.1, 64.9, 49.4, 47.1, 35.5, 29.2, 28.7, 27.0, 11.0;
31P NMR (D2O, 125 MHz, decoupled with 1H) δ 1.17 (s), 18.0
(s); HRMS (FAB, negative) calcd for C28H35N4O13P2S 729.1396
[(M - H)-], found 729.1417; UV (H2O) λmax 244, sh 270 nm.
Cyclic IDP -Ca r bocyclic-Ribose Dia ceton id e (32). Com-
pound 16 (4.4 mg, 4.7 µmol) was treated under the same
conditons as in entry 4 in Table 1 to give 32 (2.7 mg, 81%)
after purification as described for the synthesis of 12 (proce-
dure A): 1H NMR (D2O, 500 MHz) δ 8.52 (s, 1 H, H-8), 8.16
(s, 1 H, H-2), 6.32 (s, 1 H, H-1′), 5.72 (d, 1 H, H-2′, J ) 6.0),
5.47 (dd, 1 H, H-3′, J ) 6.0), 4.88 (m, 1 H, H-1′′), 4.74 (m, 2 H,
H-2′′, H-3′′), 4.56 (m, 1 H, H-4′), 4.14 (m, 1 H, H-5′′a), 4.04 (m,
2 H, H-5′), 3.74 (m, 1 H, H-5′′b), 3.19 (q, 12 H, -CH2N, J )
7.3), 2.88-2.80 (m, 2 H, H-4′′, H-6′′a), 2.62 (m, 1 H, H-6′′b),
1.64, 1.58, 1.45, 1.37 (each s, each 3 H, i-PrMe), 1.27 (t, 18 H,
CH3CH2N, J ) 7.3); 13C NMR (D2O, 125 MHz) δ 161.3, 149.5,
148.1, 145.0, 126.8, 117.2, 113.7, 94.2, 90.5, 89.0, 86.6, 85.6,
84.7, 71.2, 68.1, 67.9, 67.1, 49.4, 47.5, 29.7, 28.6, 27.0, 26.3,
22.8, 11.0; 31P NMR (D2O, 125 MHz, decoupled with 1H) δ
-10.20 (d, J ) 15.3), -10.60 (d, J ) 15.3); HRMS (FAB,
negative) calcd for C22H29N4O13P2 619.1206 [(M - H)-], found
619.1201; UV (H2O) λmax 250, sh 273 nm.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r op yliden ed ioxy)-
4-[[(bisp h en ylth iop h osp h or yl)oxy]m eth yl]cyclop en tyl]-
5′-O-(m on om e t h oxyt r it yl)-2′,3′-O-isop r op ylid e n e in o-
sin e (33). Compound 33 (165 mg, 75%) was obtained from 24
(166 mg, 200 µmol) as described for the synthesis of 27 after
purification by column chromatography (SiO2, 60% EtOAc in
hexane): 1H NMR (CDCl3, 500 MHz) δ 7.58-6.75 (m, 24 H),
7.48 (s, 1 H), 6.18 (d, 1 H, J ) 2.2), 5.47 (dd, 1 H, J ) 2.2, 6.4),
5.03 (dd, 1 H, J ) 3.7, 6.4), 4.87 (dd, 1 H, J ) 4.4, 6.7), 4.55
(m, 1 H), 4.49-4.40 (m, 3 H), 4.32 (m, 1 H), 3.32 (dd, 1 H, J )
6.9, 9.9), 3.25 (dd, 1 H, J ) 4.9, 9.9), 2.47 (m, 1 H), 2.27-2.21
(m, 2 H), 1.62, 1.54, 1.37, 1.27 (each s, each 3 H); 13C NMR
(CDCl3, 125 MHz) δ 158.5, 155.0, 147.7, 146.2, 144.3, 144.0,
137.8, 135.4, 135.4, 135.3, 130.3, 129.5, 129.4, 129.4, 129.0,
128.4, 128.3, 128.2, 127.7, 126.9, 126.9, 126.3, 126.2, 125.6,
125.3, 114.5, 113.5, 113.0, 91.4, 86.9, 86.3, 83.5, 82.8, 81.9, 80.9,
68.3, 68.3, 65.2, 63.9, 55.2, 45.3, 45.2, 32.8, 27.6, 27.2, 25.4,
25.3, 21.4; 31P NMR (CDCl3, 125 MHz, decoupled with 1H) δ
50.0 (s); HRMS (FAB, positive) calcd for C54H54BrN4NaO10PS2
1115.2100 (MNa+), found 1115.2070; UV (MeOH) λmax 272, 249,
sh 280 nm.
1
125 MHz, decoupled with H) δ 2.68 (s); HRMS (FAB, positive)
calcd for C54H58N6O10P 981.3951 (MH+), found 981.3895; UV
(MeOH) λmax 271, 236 nm. Anal. Calcd for C54H57N6O10P‚1/2H2-
O: C, 65.51; H, 5.90; N, 8.49. Found C, 65.49; H, 6.14; N, 8.14.
N-1-[(1R,2S,3R,4R)-2,3-(Isop r op ylid en ed ioxy)-4-[[(d i-
a n ilin op h osp h or yl)oxy]m eth yl]cyclop en tyl]-2′,3′-O-iso-
p r op ylid en ein osin e (30). Compound 30 (118 mg, 94%) was
obtained from 29 (175 mg, 178 µmol) as described for the
synthesis of 26 after purification by column chromatography
(SiO2, 4% MeOH in CHCl3): 1H NMR (CDCl3, 500 MHz) δ 8.01
(s, 1 H), 7.94 (s, 1 H), 7.18-6.87 (m, 10 H), 6.40 (d, 1 H, J )
8.7), 6.28 (d, 1 H, J ) 8.7), 5.90 (d, 1 H, J ) 2.1), 5.09-5.00
(m, 4 H), 4.58 (m, 1 H), 4.49 (m, 1 H), 4.35-4.23 (m, 2 H),
3.96 (dd, 1 H, J ) 1.4, 12.5), 3.80 (m, 1 H), 2.52 (m, 1 H), 2.39
(m, 1 H), 2.26 (m, 1 H), 1.64, 1.51, 1.37, 1.24 (each s, each 3
H); 13C NMR (CDCl3, 125 MHz) δ 156.4, 147.1, 146.2, 139.9,
139.6, 129.2, 129.2, 126.2, 121.9, 121.8, 118.2, 118.1, 118.1,
114.3, 113.3, 93.3, 86.2, 83.9, 83.2, 81.8, 81.3, 65.9, 63.0, 32.3,
27.6, 27.5, 25.2; 31P NMR (CDCl3, 125 MHz, decoupled with
1H) δ 2.81 (s); HRMS (FAB, positive) calcd for C34H42N6O9P
709.2750 (MH+), found 709.2743; UV (MeOH) λmax 274, 252
nm.
N-1-[(1R,2S,3R,4R)-2,3-(Isop r op ylid en ed ioxy)-4-[[(d i-
a n ilin op h osp h or yl)oxy]m et h yl]cyclop en t yl]-5′-O-[b is-
(p h en ylt h io)p h osp h or yl]-2′,3′-O-isop r op ylid en ein osin e
(31). Compound 31 (107 mg, 80%) was obtained from 30 (98
mg, 138 µmol) as described for the synthesis of 27 after
purification by column chromatography (SiO2, 90% EtOAc in
hexane): 1H NMR (CDCl3, 500 MHz) δ 7.91 (s, 1 H), 7.84 (s, 1
H), 7.50-6.85 (m, 20 H), 6.20, 6.06 (each d, each 1 H, J ) 8.5,
8.5), 6.05 (d, 1 H, J ) 2.6), 5.07 (m, 2 H), 4.92 (dd, 1 H, J )
2.6, 6.2), 4.82 (m, 1 H), 4.53 (m, 1 H), 4.45-4.40 (m, 3 H), 4.37-
4.25 (m, 2 H), 2.52 (m, 1 H), 2.43 (m, 1 H), 2.26 (m, 1 H), 1.61,
1.52, 1.36, 1.20 (each s, each 3 H); 13C NMR (CDCl3, 125 MHz)
δ 156.4, 147.0, 146.7, 139.7, 139.1, 135.2, 135.2, 135.0, 135.0,
129.7, 129.6, 129.4, 129.4, 129.0, 129.0, 125.6, 125.6, 125.5,
125.5, 121.6, 121.5, 118.0, 118.0, 114.7, 113.1, 90.5, 84.6, 84.5,
84.3, 83.2, 81.8, 80.9, 66.2, 65.5, 45.2, 45.2, 32.3, 27.6, 27.1,
25.2, 25.2; 31P NMR (CDCl3, 125 MHz, decoupled with 1H) δ
2.89 (s), 51.2 (s); HRMS (FAB, positive) calcd for C46H51N6O10
-
P2S2 973.2583 (MH)+, found 973.2547; UV (MeOH) λmax 267,
255, 233 nm.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r op yliden ed ioxy)-
4-[[(bisp h en ylth iop h osp h or yl)oxy]m eth yl]cyclop en tyl]-
2′,3′-O-isop r op ylid en ein osin e (34). Compound 34 (98 mg,
87%) was obtained from 33 (150 mg, 137 µmol) as described
for the synthesis of 26 after purification by column chroma-
tography (SiO2, 20% acetone in CHCl3): 1H NMR (CDCl3, 500
MHz) δ 7.97 (s, 1 H), 7.58-7.33 (m, 10 H), 6.09 (d, 1 H, J )
5.0), 5.18 (dd, 1 H, J ) 5.0, 6.1), 5.04 (dd, 1 H, J ) 1.1, 6.1),
4.93 (dd, 1 H, J ) 4.9, 6.4), 4.84 (m, 1 H), 4.64 (m, 1 H), 4.55
(m, 1 H), 4.47 (m, 1 H), 4.40-4.30 (m, 2 H), 3.93-3.77 (m, 2
H), 2.48-2.45 (m, 1 H), 2.27-2.21 (m, 2 H), 1.66, 1.52, 1.38,
1.27 (each s, each 3 H); 13C NMR (CDCl3, 125 MHz) δ 154.7,
147.2, 146.8, 135.3, 135.3, 129.5, 129.4, 126.2, 126.1, 126.1,
125.9, 114.4, 113.5, 93.1, 85.5, 82.8, 82.6, 81.0, 80.6, 68.0, 68.0,
65.0, 62.9, 53.8, 44.9, 44.9, 32.8, 29.2, 27.5, 27.5, 25.3, 25.2;
31P NMR (CDCl3, 125 MHz, decoupled with 1H) δ 49.9 (s);
N-1-[(1R,2S,3R,4R)-2,3-(Isopr opyliden edioxy)-4-[[(ph os-
p h or yl)oxy]m eth yl]cyclop en tyl]-5′-O-[(p h en ylth io)p h os-
p h or yl]-2′,3′-O-isop r op ylid en ein osin e (16). Using 31 (86
mg, 88 µmol) as a substrate, the reaction and purification were
carried out as described above for the synthesis of 15 to give
a mixture of 16 and a byproduct.21 The mixture was dissolved
in aqueous NaHCO3 (2%, 5 mL), and the solution was stirred
at 37 °C for 15 h. TEAA buffer (0.1 M, pH 7.0, 5.0 mL) was
added, and the resulting solution was applied to a C18 reversed
phase column (1.1 × 11 cm). The column was developed using
a linear gradient of 0-40% CH3CN in TEAA buffer (0.1 M,
(21) The HPLC analysis showed it included a byproduct, which
might be an acetylated product of 13 at the 5′-phospate moiety, since
treatment of the mixture with aqueous NaHCO3 gave the desired 5′-
phosphate 13 as a sole product.

5248 J . Org. Chem., Vol. 65, No. 17, 2000
Fukuoka et al.
HRMS (FAB, positive) calcd for C34H39BrN4O9PS2 821.1080
(MH+), found 821.1064; UV (MeOH) λmax 250, sh 274 nm.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r op ylid en edioxy)-
4-[[(bisp h en ylth iop h osp h or yl)oxy]m eth yl]cyclop en tyl]-
5′-O-(d ia n ilin op h osp h or yl)-2′,3′-O-isop r op ylid en ein o-
sin e (35). Compound 35 (90 mg, 80%) was obtained from 34
(88 mg, 107 µmol) as described for the synthesis of 25 after
purification by column chromatography (SiO2, 5% MeOH in
CHCl3): 1H NMR (CDCl3, 500 MHz) δ 7.71 (s, 1 H), 7.59-
6.76 (m, 20 H), 6.14 (d, 1 H, J ) 1.6), 5.29 (dd, 1 H, J ) 1.6,
5.3), 5.14 (dd, 1 H, J ) 3.4, 5.3), 4.93 (dd, 1 H, J ) 4.8, 6.7),
4.52 (m, 1 H), 4.47-4.45 (m, 2 H), 4.38-4.33 (m, 3 H), 4.23
(dd, 1 H, J ) 3.3, 10.4), 2.36 (m, 1 H), 2.05 (m, 2 H), 1.56,
1.53, 1.29, 1.19 (each s, each 3 H); 31P NMR (CDCl3, 125 MHz,
decoupled with 1H) δ 2.94 (s), 50.1 (s); HRMS (FAB, positive)
calcd for C46H50BrN6O10P2S2 1051.1688 (MH+), found 1051.1600;
UV (MeOH) λmax 232, sh 275, 257 nm.
8-Br om o-N-1-[(1R,2S,3R,4R)-2,3-(isop r opylid en ed ioxy)-
4-[[(p h en ylt h iop h osp h or yl)oxy]m et h yl]cyclop en t yl]-5′-
O-(p h osp h or yl)-2′,3′-O-isop r op ylid en ein osin e (13). Com-
pound 13 (47 mg, 75%) was obtained from 35 (90 mg, 86 µmol)
as described for the synthesis of 16: 1H NMR (D2O, 500 MHz)
δ 8.39 (s, 1 H, H-2), 7.57-7.20 (m, 5 H, Ar-H), 6.32 (d, 1 H,
H-1′, J ) 1.7), 5.70 (d, 1 H, H-2′, J ) 1.7, 6.5), 5.31 (dd, 1 H,
H-3′, J ) 4.0, 6.5),4.98 (m, 1 H, H-2′′), 4.95 (m, 1 H, H-1′′),
4.59 (m, 1 H, H-3′′), 4.48 (m, 1 H, H-4′), 4.07-3.97 (m, 4 H,
H-5′, H-5′′), 3.18 (q, 12 H, -CH2N, J ) 7.3), 2.41 (m, 1 H, H-4′′),
2.26-1.93 (m, 2 H, H-6′′), 1.65, 1.54, 1.44, 1.29 (each s, each
3 H, i-PrMe), 1.26 (t, 18 H, CH3CH2N, J ) 7.3); 13C NMR (D2O,
125 MHz) δ 159.6, 150.7, 149.4, 136.2, 131.8, 130.4, 126.8,
117.9, 116.7, 93.2, 88.9, 85.8, 83.8, 76.9, 74.6, 69.3, 67.2, 65.3,
63.5, 49.3, 46.6, 45.4, 35.2, 32.9, 30.8, 29.1, 28.7, 27.1, 10.9;
31P NMR (D2O, 125 MHz, decoupled with 1H) δ 0.62 (s), 17.5
(s); HRMS (FAB, negative) calcd for C28H34BrN4O13P2S 809.0481
[(M - H)-], found 809.0475; UV (H2O) λmax 249, sh 282 nm.
Cyclic 8-Br om o-IDP -Ca r bocyclic-Ribose (6). A solution
of 12 (48 OD254 units) in 60% aqueous HCO2H (1.0 mL) was
stirred at room temperature for 3.5 h. After the solvent was
evaporated, the residue was dissolved in H2O (50 mL) and
-
applied to a DEAE-Sephadex A-25 column (HCO3 form,
1.1 × 15 cm). The column was developed using a linear
gradient of 0-0.5 M TEAB buffer (pH 8.6, 200 mL). Appropri-
ate fractions were evaporated, and excess TEAB was coevapo-
rated with water. The residue was freeze-dried to give 6 (18
OD254 units, 37%) as a triethylammonium salt: 1H NMR (D2O,
500 MHz) δ 9.00 (s, 1 H, H-2), 6.17 (d, 1 H, H-1′, J ) 6.6), 5.24
(m, 1 H, H-2′), 5.17 (m, 1 H, H-1′′), 4.65 (m, 1 H, H-2′′), 4.60
(m, 1 H, H-3′), 4.41 (m, 1 H, H-4′), 4.26-4.07 (m, 5 H, H-3′′,
H-5′, H-5′′), 3.18 (q, 12 H, -CH2N, J ) 7.3), 2.91 (m, 1 H,
H-6′′a), 2.46 (m, 1 H, H-4′′), 2.20 (m, 1 H, H-6′′b), 1.27 (t, 18
H, CH3CH2N, J ) 7.3); 13C NMR (D2O, 125 MHz) δ 160.0,
151.4, 151.2, 130.8, 126.6, 93.6, 87.9, 87.8, 81.3, 75.7, 75.2, 73.6,
67.7, 61.7, 49.4, 44.9, 28.4, 11.0; 31P NMR (D2O, 125 MHz,
decoupled with 1H) δ -8.94 (d, J ) 12.0), -10.28 (d, J ) 12.0);
HRMS (FAB, negative) calcd for C16H20BrN4O13P2 616.9686
[(M - H)-], found 616.9716; UV (MeOH) λmax 256, sh 278 nm.
Ack n ow led gm en t . This investigation was sup-
ported in part by a grant from the Ministry of Educa-
tion, Science, Sports, and Culture of J apan. We are
grateful to Prof. Barry V. L. Potter (University of Bath)
for his helpful discussion.
Su p p or tin g In for m a tion Ava ila ble: 1H NMR spectral
charts of 6, 13, 15, 16, 23, 24, 26, 30, 31, 32, 33, 34, and 35
and HPLC charts of 3, 6, 11, 12, 13, 14, 15, 16, and 32. This
material is available free of charge via the Internet at
http://pubs.acs.org.
J O0000877