Synthesis of glucopyranoside-based ligands for D-myo-inositol 1,4,5-trisphosphate receptors

Article abstract of DOI:10.1016/S0008-6215(02)00103-9

Adenophostins A and B are naturally occurring glyconucleotides that interact potently with receptors for D-myo-inositol 1,4,5-trisphosphate, an important second messenger molecule in most cell types. Here we describe the design and synthesis of glucopyranoside-based analogues of adenophostin A lacking the adenine component. The key synthetic strategy involves glycosylation of selectively protected alcohols, derived from methyl β-D-ribofuranoside or 1,4-anhydroerythritol, using glycosyl donors synthesised from 2,6-di-O-benzyl-D-glucopyranose derivatives. Further elaboration and deprotection of the coupled products gave two trisphosphate analogues; methyl 3-O-α-D-glucopyranosyl-β-D-ribofuranoside 2,3′,4′-trisphosphate ("ribophostin") and (3′S,4′R)-3′-hydroxytetrahydrofuran-4′-yl α-D-glucopyranoside 3,4,3′-trisphosphosphate ("furanophostin"). The route to furanophostin was further modified to give (3′S,4′R)-3′-hydroxytetrahydrofuran-4′-yl α-D-glucopyranoside 3′-phosphate 3,4-bisphosphorothioate, the first phosphorothioate-containing adenophostin analogue.

Full text of DOI:10.1016/S0008-6215(02)00103-9

Carbohydrate Research 337 (2002) 1067–1082
www.elsevier.com/locate/carres
Synthesis of glucopyranoside-based ligands for
1,4,5-trisphosphate receptors
D-myo-inositol
Andrew M. Riley, David J. Jenkins, Rachel D. Marwood, Barry V.L. Potter*
Wolfson Laboratory of Medicinal Chemistry, Department of Pharmacy and Pharmacology, Uni6ersity of Bath, Cla6erton Down,
Bath BA2 7AY, UK
Received 10 December 2001; accepted 10 April 2002
Dedicated to the memory of Professor Roy H. Gigg (1930–2001).
Abstract
Adenophostins A and B are naturally occurring glyconucleotides that interact potently with receptors for
D
-myo-inositol
1,4,5-trisphosphate, an important second messenger molecule in most cell types. Here we describe the design and synthesis of
glucopyranoside-based analogues of adenophostin A lacking the adenine component. The key synthetic strategy involves
glycosylation of selectively protected alcohols, derived from methyl b-
donors synthesised from 2,6-di-O-benzyl- -glucopyranose derivatives. Further elaboration and deprotection of the coupled
products gave two trisphosphate analogues; methyl 3-O-a- -glucopyranosyl-b- -ribofuranoside 2,3%,4%-trisphosphate (‘‘ri-
bophostin’’) and (3%S,4%R)-3%-hydroxytetrahydrofuran-4%-yl a- -glucopyranoside 3,4,3%-trisphosphosphate (‘‘furanophostin’’). The
route to furanophostin was further modified to give (3%S,4%R)-3%-hydroxytetrahydrofuran-4%-yl a- -glucopyranoside 3%-phosphate
D-ribofuranoside or 1,4-anhydroerythritol, using glycosyl
D
D
D
D
D
3,4-bisphosphorothioate, the first phosphorothioate-containing adenophostin analogue. © 2002 Elsevier Science Ltd. All rights
reserved.
Keywords: Adenophostin; myo-Inositol; Glucose; Ribose; 1,4-Anhydroerythritol; Glycosylation; Sugar phosphates; Phosphorothioates
1. Introduction
-myo-Inositol 1,4,5-trisphosphate [Ins(1,4,5)P3, 1]
group. The most active of these analogues attained
similar potencies to that of Ins(1,4,5)P3, but none has
surpassed it.
1D
acts as a second messenger in most cells, where it binds
to tetrameric intracellular receptors [IP3Rs], resulting in
the opening of an intrinsic Ca2+ channel through
which Ca2+ flows from the lumen of the endoplasmic
reticulum into the cytosol.1 Since the discovery of the
second messenger function of Ins(1,4,5)P3, many syn-
thetic analogues of Ins(1,4,5)P3 have been prepared.2
Structure–activity studies of these have shown that all
high-affinity agonists of IP3Rs contain groups equiva-
lent to the 4R,5R-trans-diequatorial bisphosphate and
adjacent 6-hydroxyl group of Ins(1,4,5)P3, together
with an appropriately positioned non-vicinal phosphate
In 1993, adenophostins A and B, isolated3 from
culture broths of Penicillium bre6icompactum, were
shown to stimulate the release of Ca2+ from
Ins(1,4,5)P3-sensitive intracellular stores and to bind to
cerebellar IP3Rs with higher affinity than any other
known ligand, including Ins(1,4,5)P3. Adenophostins
A and B were identified as 3%-O-a-D-glucopyran-
osyladenosine 2%,3%%,4%%-trisphosphate (2a) and its 6%%-O-
acetyl ester (2b), respectively.4,5 Several total syntheses
of 2a have since appeared.6–8 It was quickly realised
that the glucose 3%%,4%%-bisphosphate/2%%-hydroxyl struc-
ture of the adenophostins was able to mimic the inosi-
tol 4,5-bisphosphate/6-hydroxyl triad of Ins(1,4,5)P3 at
the binding sites of IP3Rs,5 although the precise role of
the 2%-phosphorylated adenosine component, and how
this structure could confer enhanced affinity for IP3Rs,
was not clear.
* Corresponding author. Tel.: +44-1225-826639; fax: +
44-1225-826114.
E-mail address: prsbvlp@bath.ac.uk (B.V.L. Potter).
0008-6215/02/$ - see front matter © 2002 Elsevier Science Ltd. All rights reserved.
PII: S0008-6215(02)00103-9

1068
A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
Fig. 1. Structures of Ins(1,4,5)P3 (1), adenophostins A (2a) and B (2b), and synthetic analogues (3–6).
yl a-D-glucopyranoside 3%-phosphate-3,4-bisphospho-
Initial attempts to elucidate the role of the adenosine
-glucopyran-
rothioate (6) as a potential high-affinity partial agonist,
is described. Preliminary accounts of the syntheses of
412 and 513 have appeared, and 5 has been synthesised
by another group (Fig. 1).14 A comprehensive struc-
ture–activity study incorporating these ligands has
been published.15
led to the synthesis of 2-hydroxyethyl a-
D
oside 2%,3,4-trisphosphate9,10 (3) which was found to be
around tenfold less potent9–11 than Ins(1,4,5)P3. This
suggested that, while the pyranoside 3,4-bisphosphate/
2-hydroxyl component contained the essential struc-
tures responsible for binding and Ca2+ release, at least
part of the adenosine moiety was required for the high
potency of the adenophostins. Molecular modelling
simulations9 of
3
established that its flexible
2. Results and discussion
bimethylene chain did not allow the 2%-phosphate to
mimic accurately the corresponding phosphate of either
1 or 2a. In the present paper we describe the synthesis
For the synthesis of 4, the intermediate methyl 5-O-
benzyl-2-O-p-methoxybenzyl-b-
(Scheme 1) was required as a suitable glycosyl acceptor.
-Ribose was converted into the known16 methyl b-
D-
D
-ribofuranoside (13)
of methyl 3-O-a-
D
-glucopyranosyl-b-
D-ribofuranoside
D
2,3%,4%-trisphosphate (4) and (3%S,4%R)-3%-hydroxytetra-
ribofuranoside 8. The acid-catalysed reaction of 8 with
1.05 equivalents of p-methoxybenzaldehyde dimethyl
acetal17 at 70 °C in DMF with continuous removal of
the liberated MeOH gave the 2,3-O-p-methoxybenzyli-
dene derivative 9ab. Compound 9ab has been prepared
previously,18 but NMR data, showing it to be a ca. 3:2
diastereoisomeric mixture, are reported here for the first
time. Benzylation of 9ab with NaH and benzyl bromide
gave fully protected 10ab, again as a 3:2 diastereomeric
mixture. Cleavage of the p-methoxybenzylidene acetal
hydrofuran-4%-yl a-D-glucopyranoside 3,3%,4-trisphos-
phate (5),† in both of which the adenine ring of 2a has
effectively been deleted, but the third phosphate is held
on a furanoid ring as in 2a. In addition, the design and
preparation of (3%S,4%R)-3%-hydroxytetrahydrofuran-4%-
† In naming some compounds of this paper note that
primes have been used when not strictly necessary, to facili-
tate understanding of structure–activity arguments and NMR
spectral assignments.

A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
1069
Scheme 1. (a) MeOH, H2SO4; (b) p-MeOC6H4CH(OMe)2, PTSA, DMF, 70 °C; (c) NaH, BnBr, DMF; (d) DIBAL–H, CH2Cl2;
,
(e) Ac2O, pyridine; (f) DDQ, CH2Cl2, 3 A MS; (g) 80% acetic acid, 60 °C; (h) see Ref. 10; (i) Cl3CCN, K2CO3, CH2Cl2; (j)
Me3SiOSO2CF3, Et2O, 4 A MS; (k) DDQ, 12:1 CH2Cl2–H2O; (l) (BnO)2PNPr2, CH2Cl2, 1H-tetrazole then MCPBA, −78 °C to
i
,
rt; (m) H2, Pd–C, 40 psi, 4:1 MeOH–H2O. PMB=p-methoxybenzyl.
with LiAlH4–AlCl3 in refluxing tetrahydrofuran,19
NaCNBH3–Me3SiCl in acetonitrile17 or DIBAL–H in
dichloromethane20 all gave the required 13, but also the
more polar isomer 11, in approximately equal propor-
tions, the latter reagent giving by far the best yield. The
structures of 11 and 13 were confirmed by preparation
of acetates 12 and 14, respectively, the 1H NMR spectra
of which, respectively, revealed a deshielded doublet
corresponding to H-2, and a deshielded triplet corre-
sponding to H-3. The enantiomer of 11 has previously
been prepared as part of an anomeric mixture, but no
physical data were reported.21 Although the regioselec-
tivity of acetal cleavage was somewhat disappointing,
the unrequired isomer 11 was easily re-oxidised to 10ab
(interestingly, as a 92:8 diastereomeric mixture) using
2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in
dry dichloromethane.22
with 80% (v/v) aq acetic acid to give 15. Therefore, 10ab
appears to be a more suitable intermediate than methyl
2,3-O-isopropylidene-b-
D
-ribofuranoside to prepare
derivatives of methyl b-D-ribofuranoside substituted at
C-5.
With a suitable glycosyl acceptor in hand, an appro-
priate donor was required. Reaction of the known10 2,6
-di-O-benzyl-3,4-di-O-p-methoxybenzyl-D-glucopyran-
ose (16) with trichloroacetonitrile in the presence of
potassium carbonate24 resulted in the initial formation
of the required b anomer 17b, the kinetic product,
accompanied by slow conversion into the a anomer 17a,
which is the thermodynamic product. The reaction was
monitored closely by TLC and quenched when the
optimum conversion to the b anomer was observed,
before the formation of too much of the a anomer.
Flash chromatography yielded crystalline 17b in only
moderate yield (48%), accompanied by significant quan-
tities of 17a. Configurations of the two anomers were
A preparation of the corresponding 2-O- and 3-O-al-
lyl ribofuranosides by a different route has been re-
ported by Desai et al.23 This report described
anomerisation of methyl 5-O-benzyl-2,3-O-isopropyli-
1
easily assigned on the basis of their H NMR spectra.
The axial H-1 of the b anomer exhibited a typically large
coupling constant of 8.3 Hz and was upfield (l 5.78) of
the equatorial H-1 of the a anomer, (l 6.51, J1,2 3.3 Hz).
The trichloroacetimidate NH proton was also clear in
dene-b-D-ribofuranoside on acidic hydrolysis, to give a
ca. 1:4 a:b-anomeric mixture of products. We found that
the more labile p-methoxybenzylidene acetal of 10ab
could be removed without anomerisation by treatment
1
the H NMR spectra of both anomers.

1070
A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
Coupling of 13 and 17b was achieved using
activity of 4 relative to the adenophostins suggested
that the adenine (or similar) moiety was required to
engender potency greater than that of Ins(1,4,5)P3.
Analogues of 2a in which adenine has been replaced by
imidazole, purine, benzimidazole, uracil and other aro-
matic structures have subsequently been prepared by
this group.25–27 The demonstration of Ins(1,4,5)P3-like
potency for 4, however, raised the question as to
whether this compound represented the minimal struc-
ture for such activity in carbohydrate polyphosphates.
In particular, would conformational restraint of the
third phosphate using a tetrahydrofuran ring alone
engender comparable potency, or did the 4-hydrox-
ymethyl and/or 1-methoxyl groups of 4 somehow con-
tribute to activity? Such considerations led to the design
of 5.
The glycosyl acceptor required for the synthesis of 5,
(+)-22 (Scheme 2), was prepared from commercially
available 1,4-anhydroerythritol (21) by the optical reso-
lution of its racemic p-methoxybenzyl ether (9)-22.
Attempts to obtain (9)-22 by monoalkylation of 21
using NaH and p-methoxybenzyl chloride in DMF
failed, as only dialkylated material was formed. How-
ever, preparation of the p-methoxybenzylidene acetal
followed by reductive cleavage, similarly to reactions on
10ab, gave (9)-22 in excellent yield. Esterification of
(9)-22 with (−)-(S)-camphanic chloride gave the
chromatographically separable, crystalline diastereoiso-
mers 23 and 24. Saponification of the esters gave enan-
trimethylsilyl triflate as a promoter in ether at room
temperature, conditions which generally favour a-
stereoselectivity.24 The product ran as a single spot on
1
TLC, but the H NMR spectrum clearly demonstrated
that although the a-glucopyranosyl compound 18a had
been formed as the major product, the b-glucopyran-
osyl anomer 18b was present as a ca. 20% contaminant,
which could not be removed at this stage. However, on
treatment of the mixture with DDQ, the required crys-
talline triol 19a could be separated from the b-coupled
isomer 19b by column chromatography. Phosphityla-
tion of 19a with bis(benzyloxy)diisopropylamino-
phosphine followed by oxidation of the intermediate
trisphosphite triester with m-chloroperoxybenzoic acid
(MCPBA) gave the fully protected trisphosphate 20.
Compound 20 was deprotected by hydrogenolysis over
palladium on carbon to give the required trisphosphate
4 which was purified by ion-exchange chromatography
on Q Sepharose Fast Flow resin. Surprisingly, the
isolated triethylammonium salt of 4 was poorly soluble
in water, and it was therefore converted into the freely
soluble hexapotassium salt before use.
The activity of trisphosphate 4 in displacement of
[3H]Ins(1,4,5)P3 from the Ins(1,4,5)P3 receptors of hep-
atic membranes and in release of Ca2+ from hepato-
cytes was found to be very similar to that of
Ins(1,4,5)P3 itself, although still about 10- to 20-fold
lower than that of adenophostin A.11,15 The lower
Scheme 2. (a) p-MeOC6H4CH(OMe)2, PTSA, DMF, 70 °C; (b) DIBAL–H, CH2Cl2; (c) (−)-(S)-camphanic chloride, pyridine,
0 °C to rt; (d) NaOH, MeOH, reflux; (e) NaH, BnBr, DMF; (f) CF3COOH, CH2Cl2. PMB=p-methoxybenzyl.

A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
1071
i
,
Scheme 3. (a) AgClO4, ZnCl2, dioxane, toluene, 4 A MS; (b) CF3COOH, CH2Cl2; (c) (BnO)2PNPr2, 1H-tetrazole then MCPBA,
−78 °C to rt; (d) H2, Pd–C, 40 psi, 5:1 MeOH–H2O. PMB=p-methoxybenzyl.
tiomeric p-methoxybenzyl ethers (−)-22 and (+)-22,
which were highly crystalline, in contrast to the racemic
mixture. The absolute configurations of (−)-22 and
(+)-22 were established by converting (−)-22 into
monobenzyl ether 25, identified by comparison of its
optical rotation with that of its known28 enantiomer.
Glycosylation of (+)-22 (Scheme 3) was achieved by
reaction with dimethyl phosphite 26ab8 in the presence
of ZnCl2 and AgClO4.29 Glycosyl donor 26ab was
chosen rather than trichloroacetimidate 17b due to
greater ease of preparation and because phosphite-me-
diated coupling tends to give a higher proportion of
a-coupled products. In the present case, only the re-
quired a-glycoside 27 was isolated, in 74% yield. The
three p-methoxybenzyl ethers were smoothly removed
from 27 to give 28 using 10% trifluoroacetic acid in
dichloromethane,30 superior conditions in our hands to
the DDQ-mediated cleavage used on 18ab. Triol 28 was
phosphitylated and oxidised as described for triol 19a
giving 29, which was deprotected using catalytic hy-
drogenolysis to give the target compound 5.
although in adenophostin A itself it may still be in-
volved, as adenophostin A may interact with the recep-
tor differently to 4 and 5. Second, because 5 can be
viewed as a conformationally restricted analogue of 3,
but is more potent than it, the view that the limited
potency of 3 is related to the flexibility and/or over-ex-
tended conformation of the ethylphosphate structure9
receives strong support; clearly conformational restric-
tion alone can markedly enhance activity. Third, since 4
and 5 are essentially equipotent with Ins(1,4,5)P3, but
more potent than other disaccharide-based Ins(1,4,5)P3
analogues,11,15 it is probable that their common fura-
noid ring structure presents their 2- and 3%-phosphates,
respectively, in an optimal position for Ins(1,4,5)P3-like
potency. Finally, it is notable that 4 and 5, like the
adenophostins, appear to behave as full agonists of
hepatic Ins(1,4,5)P3 receptors, in that maximal doses of
4, 5 and Ins(1,4,5)P3 all mobilise the same portion of
the intracellular Ca2+ stores.
The replacement of phosphate groups in certain inos-
itol phosphates with phosphorothioates can give partial
agonists, which bind to Ins(1,4,5)P3 receptors, but re-
lease only a fraction of the Ins(1,4,5)P3-releasable Ca2+
pool.2,31,32 Such compounds could provide a step to-
wards the development of Ins(1,4,5)P3 receptor antago-
nists. In a recent example, replacement of the 4- and
5-phosphate groups of 3-deoxy-3-fluoro-Ins(1,4,5)P3
with phosphorothioates produced a partial agonist with
an affinity only tenfold less than Ins(1,4,5)P3 for type 1
Ins(1,4,5)P3 receptors.33 We reasoned that adeno-
phostin analogues, such as 5, might be promising candi-
dates for this approach in that they are related to C-3
modified Ins(1,4,5)P3 analogues [hydroxymethyl of glu-
cose replacing 3-hydroxyl of Ins(1,4,5)P3)] and retain
When tested for Ca2+ release from permeabilised
hepatocytes, 5 behaved as a full agonist with a potency
similar to Ins(1,4,5)P3 and to 4.13,15 Several conclusions
may be drawn relating to the structural basis for the
activity of 3, 4, 5 and adenophostin A. First, the similar
behaviour of 4 and 5 indicates that the 1-methoxyl
group of 4 does not hinder activity, but neither does it
enhance it. Subsequent studies have shown that even
when this methoxyl group is replaced by imidazole,
giving
a
compound more obviously similar to
adenophostin A, the activity is not substantially in-
creased.26 Similarly, the 4-hydroxymethyl group of 4 is
not essential for high potency at Ins(1,4,5)P3 receptors,

1072
A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
high affinity for the receptor. Furthermore, their struc-
ture (non-vicinal phosphate located on a separate ring)
has advantages in terms of convergent synthetic strat-
egy for creating novel ligands with the 2%-phosphate and
3,4-bisphosphorothioate pattern. In 6, the two vicinal
phosphate groups of furanophostin (5) have been re-
placed by phosphorothioates to give the first phospho-
rothioate-containing adenophostin analogue, fura-
nophostin-PS2.
The synthetic route to 6 (Scheme 4) required a glyco-
syl donor in which the 3- and 4-hydroxyl groups of
glucose could selectively be exposed in the final stages
of the synthesis, allowing late introduction of the sensi-
tive vicinal bisphosphorothioate structure. This was
conveniently achieved using the glycosyl donor 30ab,26
in which O-3 and O-4 of glucose are protected as
acetate esters. Thus, ZnCl2/AgClO4-mediated glycosyla-
tion of (+)-22 with 30ab was employed, giving solely
the a-coupled product 31. The two acetate groups have
a deactivating effect on the glycosyl donor,34 and the
reaction was considerably slower than the correspond-
ing glycosylation of (+)-22 with 26ab. The single p-
methoxybenzyl ether of 31 was smoothly cleaved using
10% trifluoroacetic acid in dichloromethane30 without
anomerisation to give the crystalline alcohol 32, and the
exposed hydroxyl group was subjected to phosphityla-
tion followed by oxidation as before giving 33. Cleav-
age of the two acetate esters on glucose using
ammonia-saturated MeOH at room temperature re-
quired overnight reaction, conditions which resulted in
the formation of more polar products, presumably
from unwanted attack on the dibenzylphosphate ester.
However, the required diol 34 was isolated in moderate
(64%) yield. Phosphitylation of 34 with bis(benzy-
loxy)diisopropylaminophosphine as before now gave an
intermediate bisphosphite, which was reacted with ele-
mental sulphur in pyridine–DMF35 to give fully-pro-
tected 35. Total deprotection using sodium in liquid
ammonia, and final purification by ion-exchange chro-
matography as before gave the target compound 6. The
31P NMR spectrum of 6 was distinctive, showing a
single peak corresponding to the 3%-phosphate group at
high field (0.68 ppm) with the phosphorus atoms of the
3- and 4-phosphorothioate groups resonating much
further downfield at 51.42 and 50.01 ppm.
In displacement of [3H]Ins(1,4,5)P3 from the
Ins(1,4,5)P3 receptors of hepatic membranes,15 6 was
found to be around fivefold weaker than the corre-
sponding trisphosphate 5, demonstrating that, as ex-
pected from studies with inositol polyphosphates,
phosphorothioate substitution of the vicinal bisphos-
phate leads to a decrease in affinity for Ins(1,4,5)P3
receptors. However, maximal concentrations of
Ins(1,4,5)P3 and 6 each caused similar amounts of
Ca2+ to be released from the intracellular stores of
permeabilised hepatocytes.15 These preliminary results
suggest that 6 behaves as a full agonist of hepatic
Ins(1,4,5)P3 receptors, although rapid measurements of
rates of Ca2+ release will be required to establish the
efficacy of 6 unequivocally. A possible explanation for
the apparent high efficacy of 6 may be that its hydrox-
ymethyl group closely mimics the 3-hydroxyl of
i
,
Scheme 4. (a) AgClO4, ZnCl2, dioxane, toluene, 4 A MS; (b) CF3COOH, CH2Cl2; (c) (BnO)2PNPr2, 1H-tetrazole, CH2Cl2, then
MCPBA, −78 °C to rt; (d) NH3–satd MeOH; (e) (BnO)2PNPri2, CH2Cl2, 1H-tetrazole then S8, DMF, pyridine; (f) Na, liquid
NH3, −78 °C. PMB=p-methoxybenzyl.

A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
1073
Ins(1,4,5)P3 and therefore does not provide sufficient
structural perturbation2,33 around the pseudo-3 position
to significantly reduce efficacy. Future attempts to de-
velop phosphorothioate-containing adenophostin ana-
logues as partial agonists or antagonists may therefore
require more substantial modification to C-5 of the
pyranoside ring.
EX400 NMR spectrometers. 31P NMR spectra were
recorded on JEOL FX90Q or EX400 NMR spectrome-
ters and 31P NMR chemical shifts were measured in
ppm relative to external 85% H3PO4. Melting points
(uncorrected) were determined using a Reichert–Jung
Thermo Galen Kofler block. Microanalysis was carried
out at the University of Bath Microanalysis Service.
Mass spectra were recorded at the University of Bath
using m-nitrobenzyl alcohol (NBA) as the matrix. Opti-
cal rotations were measured at rt using an Optical
Activity Ltd. AA-10 polarimeter. Ion-exchange chro-
matography was performed on an LKB-Pharmacia
medium pressure ion-exchange chromatograph using Q
Sepharose Fast Flow resin and gradients of triethylam-
monium hydrogen carbonate (TEAB) as eluent. Com-
pounds containing phosphates were assayed quan-
titatively using the Ames phosphate assay38 or by a
modification of the Briggs phosphate assay.39
In summary, we have described the synthesis of three
glucopyranoside-based Ins(1,4,5)P3 receptor ligands 4, 5
and 6 related to the adenophostins but lacking the
adenine. In 6, the important vicinal bisphosphate struc-
ture common to the adenophostins and Ins(1,4,5)P3 has
been replaced with a bisphosphorothoioate to give the
first phosphorothioate-containing adenophostin ana-
logue. Compounds 4 and 5 (ribophostin and fura-
nophostin) interact potently with Ins(1,4,5)P3 receptors,
although with equilibrium binding affinities lower than
that of adenophostin A itself, and similar to that of the
natural ligand Ins(1,4,5)P3. The 3,4-bisphosphoroth-
ioate analogue of 5 (furanophostin-PS2, 6) has lower
affinity for hepatic Ins(1,4,5)P3 receptors and, at least in
initial experiments, appears to behave as a full agonist.
Evidence is now emerging that, under some condi-
tions, adenophostin analogues such as 4 and 5 may not
behave simply as mimics of Ins(1,4,5)P3, but are more
similar to the adenophostins. A recent electrophysiolog-
ical study of the effects of 4 and 5 in Xenopus oocytes36
showed that in the absence of ATP, 4 and 5 activated
Ins(1,4,5)P3 receptor channels with gating properties
similar to those of adenophostin A, and unlike those of
Ins(1,4,5)P3. Furthermore, electrophysiological studies
in rat basophilic leukaemia (RBL-1) cells have now
shown that under physiological conditions of low intra-
cellular Ca2+ buffering, ribophostin (4) behaves simi-
larly to adenophostin A in activating the store-operated
Ca2+ current (ICRAC) while Ins(1,4,5)P3 is largely inac-
tive.37 Further studies using 5, 6 and other analogues
are in progress. Thus, it appears that in some cases,
adenophostin A has qualitatively different effects on
Ca2+ signalling to Ins(1,4,5)P3 and that, surprisingly,
adenophostin analogues such as 4 and 5 may sometimes
behave as adenophostin mimics rather than as mimics
of Ins(1,4,5)P3. These compounds may therefore be
useful tools for the investigation of intracellular Ca2+
signalling.
Methyl
2,3-O-p-methoxybenzylidene-i-D-ribofura-
noside (9ab).—A 100 mL flask containing methyl b-
D
-
ribofuranoside 816 (4.23 g, 25.8 mmol), dry DMF (50
mL), p-methoxybenzaldehyde dimethyl acetal17 (4.9 g,
27 mmol) and p-toluenesulfonic acid (50 mg) was fitted
with an air condenser, attached to a water pump and
evacuated. The solution was stirred at 70 °C until
MeOH ceased to condense (4 h), then NaHCO3 (0.5 g)
was added and the suspension was allowed to cool to
rt. The solvents were evaporated and the colourless oil
was extracted with ether (2×150 mL). The combined
organic extracts were washed with water (150 mL),
dried (MgSO4), filtered and concentrated to give the
title compound as a colourless oil, which was shown by
1H NMR to be a ca. 3:2 diastereoisomeric mixture (6.80
g, 93%); [h]D −43° (c 3.1, CHCl3), lit.18 −61°; 1H
NMR (CDCl3; 400 MHz):l 7.43–7.37 (m, 2 H, ortho-H
of p-methoxyphenyl), 6.92–6.89 (m, 2 H, meta-H of
p-methoxyphenyl), 5.92 (s, 0.4 H, ArCHOm2 in), 5.72 (s,
0.6 H, ArCHOm2 aj), 5.12 (s, 0.6 H, H-1maj), 5.09 (s, 0.4
H, H-1min), 4.96, 4.70 (AB, 0.8 H, J2,3 5.6 Hz, H-2min
and H-3min), 4.88, 4.66 (AB, 1.2 H, J2,3 6.3 Hz, H-2maj
and H-3maj), 4.60 (t, 0.6 H, J 2.9 Hz, H-4maj), 4.52 (t,
0.4 H, J 2.9 Hz, H-4min), 3.80 (s, 3 H, ArOMe),
3.74–3.65 (m, 2 H, H-5a, H-5b), 3.46 (s, 3 H, OMe),
3.32 (dd, 0.6 H, J 10.5, 3.4 Hz, exch D2O, OHmaj), 3.16
(dd, 0.4 H, J 9.8, 3.4 Hz, exch D2O, OHmin); 13C NMR
(CDCl3; 100.4 MHz): l 160.84, 160.68 (2×para-C),
132.00 (ipso-C), 128.35 (ortho-Cmaj), 128.07 (ortho-
Cmin), 113.83 (meta-C), 109.64 (C-1maj), 105.74
(ArCHOm2 aj), 104.08 (ArCHOm2 in), 88.11, 86.16, 84.98,
82.33, 80.96 (C-2ꢀC-4), 64.04 (C-5min), 63.95 (C-5maj),
55.30, 55.56 (2×OMe). The ‘‘min’’ and ‘‘maj’’ super-
scripts denote signals arising from the minor and major
diastereoisomers, respectively.
3. Experimental
General
methods.—Thin-layer
chromatography
(TLC) was performed on pre-coated plates (E. Merck
aluminium sheets silica 60 F254). Products were visu-
alised by spraying with phosphomolybdic acid in
MeOH followed by heating. Flash chromatography was
Methyl 5-O-benzyl-2,3-O-p-methoxybenzylidene-i-D-
ribofuranoside (10ab).—A solution of 9ab (6.1 g, 21.6
1
carried out using Sorbsil C60 Silica Gel. H and 13C
NMR spectra were recorded on JEOL JNM EX270 or
mmol) in dry DMF (250 mL) was stirred at rt with

1074
A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
NaH (1.08 g of a 60% w/w dispersion in mineral oil,
27.0 mmol) and benzyl bromide (2.8 mL, 23.8 mmol)
for 2.5 h, when TLC (EtOAc) indicated consumption of
the starting material (Rf 0.35) to give a product (Rf 0.7).
MeOH (20 mL) was added and stirring was continued
for 30 min. The solvents were evaporated and the
mixture was extracted with ether (2×200 mL). The
combined organic layer was washed with water (200
mL), dried, filtered and concentrated. The syrup thus
obtained was purified by flash chromatography (eluent
9:1 then 7:3 hexane–EtOAc) to give the title compound
4.67–4.50 (m, 4 H, 2 overlapping ArCH2O AB sys-
tems), 4.17–4.07 (br m, 2 H, sharpens on D2O exch,
H-3, H-4), 3.83 (dd, 1 H, J2,3 3.7 Hz, H-2), 3.79 (s, 3 H,
ArOMe), 3.63 (dd, 1 H, J5a,5b 10.4, J5a,4 3.5 Hz, H-5a),
3.54 (dd, 1 H, J5b,4 6.1 Hz, H-5b), 3.32 (s, 3 H, OMe),
2.70–2.50 (br s, 1 H, exch D2O, OH); 13C NMR
(CDCl3; 67.8 MHz): l 159.56 (para-C of PMB), 138.22
(ipso-C of Bn), 129.64 (Ar), 129.21 (ipso-C of PMB),
128.33, 127.61,127.54 (Ar), 113.97 (meta-C of PMB),
105.85 (C-1), 83.17, 81.62 (C-2, C-4), 73.28, 72.53 (2×
ArCH2O), 71.71 (C-3), 71.61 (C-5), 55.25, 55.16 (2×
OMe); FABMS (positive ion): m/z 374 ([M+], 10%),
121 (100). Anal. Calcd for C21H26O6: C, 67.35; H, 7.00.
Found: C, 67.4; H, 7.05.
1
as a pale yellow oil, which was shown by H NMR to
be a ca. 3:2 diastereoisomeric mixture (6.5 g, 81%); [h]D
1
−22.6° (c 3.4, CHCl3); H NMR (CDCl3; 270 MHz): l
7.44–7.24 (m, 7 H, Ar), 6.92–6.85 (m, 2 H, meta-H of
p-methoxyphenyl), 5.92 (s, 0.4 H, ArCHOm2 in), 5.73 (s,
0.6 H, ArCHOm2 aj), 5.11 (s, 0.6 H, H-1maj), 5.07 (s, 0.4
H, H-1min), 4.89–4.42 (m, 5 H, H-2, H-3, H-4,
PhCH2O), 3.79 (s, 3 H, ArOMe), 3.57–3.50 (m, 2 H,
H-5a, H-5b), 3.32 (s, 3 H, OMe); 13C NMR (CDCl3;
100 MHz): l 160.77 (para-Cmaj of p-methoxyphenyl),
160.61 (para-Cmin of p-methoxyphenyl), 137.98 (ipso-
Cmaj of Bn), 137.91 (ipso-Cmin of Bn), 128.38, 128.35,
128.16, 128.09, 127.69, 127.63 (Ar), 113.77 (meta-C of
p-methoxyphenyl), 108.94 (C-1maj), 108.81 (C-1min),
106.02 (ArCHO2maj), 104.08 (ArCHOm2 in), 85.72, 84.91,
84.51, 84.18, 82.64, 81.86 (C-2–C-4), 73.24
(PhCH2Omin), 73.19 (PhCH2Omaj), 71.05 (C-5min), 70.94
(C-5maj), 55.26, 54.77, (2×OMe). The ‘‘min’’ and
‘‘maj’’ superscripts denote signals arising from the mi-
nor and major diastereoisomers, respectively. FABMS
(positive ion): m/z 373 ([M+1]+, 40%), 91 (100). Anal.
Calcd for C21H24O6: C, 67.71; H, 6.50. Found: C, 67.6;
H, 6.45.
A sample of 13 was converted into its acetate 14 with
Ac2O in pyridine; Rf 0.55 (10:1 CHCl3–Me2CO); [h]D
+17.5° (c 2.4, CHCl3); H NMR (CDCl3; 270 MHz): l
1
7.34–7.26 (m, 5 H, Ph), 7.25–7.20 (m, 2 H, ortho-H of
PMB), 6.90–6.82 (d, 2 H, meta-H of PMB), 5.13 (t, 1
H, J3,2=J3,4=5.3 Hz, H-3), 4.89 (d, 1 H, J1,2 2.0 Hz,
H-1), 4.62–4.48 (m, 4 H, 2×overlapping ArCH2O AB
systems), 4.32 (q, 1 H, J4,5a=J4,5b=5.3 Hz, H-4), 4.06
(dd, 1 H, H-2), 3.79 (s, 3 H, ArOMe), 3.58–3.56 (m, 2
H, H-5a, H-5b), 3.34 (s, 3 H, OMe), 2.07 (s, 3 H,
MeCO2); FABMS (positive ion): m/z 416 ([M+], 25%),
121 (100). Anal. Calcd for C23H28O7: C, 66.32; H, 6.78.
Found: C, 66.6; H, 6.69.
Further elution gave 11 as a pale yellow syrup (371
mg, 33%); Rf 0.3 (10:1 CHCl3–Me2CO); [h]D −28.8° (c
1
1.6, CHCl3); H NMR (CDCl3; 400 MHz): l 7.35–7.19
(7 H, m, Ar); 6.88–6.82 (m, 2 H, meta-H of PMB), 4.85
(s, 1 H, H-1), 4.56 (s, 2 H, ArCH2O), 4.49 (s, 2 H,
ArCH2O), 4.20 (q, 1 H, J4,3=J4,5a=J4,5b=5.8 Hz,
H-4), 4.04 (dd, 1 H, J3,2 4.9 Hz H-3), 3.99 (d, 1 H, H-2),
3.78 (s, 3 H, ArOMe), 3.54–3.49 (m, 2 H, H-5a, H-5b),
3.31 (s, 3 H, OMe), 2.80–2.26 (br s, 1 H, exch D2O,
OH); 13C NMR (CDCl3; 67.8 MHz): l 159.58 (para-C
of PMB), 138.15 (ipso-C of Bn), 129.66 (Ar), 129.17
(ipso-C of PMB), 128.33, 127.61 (Ar), 113.95 (meta-C
of PMB), 108.52 (C-1), 80.54, 79.15 (C-2–C-4), 73.24,
72.46, 71.62 (C-5, 2×ArCH2O), 55.25, 54.99 (2×
OMe); FABMS (positive ion): m/z 374 ([M+], 20%),
121 (100). Anal. Calcd for C21H26O6: C, 67.35; H, 7.00.
Found: C, 67.5; H, 7.07.
Methyl 5-O-benzyl-2-O-p-methoxybenzyl-i-
furanoside (13) and methyl 5-O-benzyl-3-O-p-methoxy-
benzyl-i- -ribofuranoside (11).—A solution of
D-ribo-
D
DIBAL–H (1.0 M in CH2Cl2; 15 mL, 15.0 mmol) was
added dropwise to a solution of acetal 10ab (1.12 g, 3.0
mmol) in dry CH2Cl2 (10 mL) at −78 °C. The solution
was stirred at −78 °C for 10 min, then was warmed to
0 °C over 90 min. MeOH (10 mL) was added dropwise
and the system solidified to a gel. 10% w/v aq KOH (30
mL) was added to dissolve the gel and the resultant
biphasic solution was diluted with CH2Cl2 (100 mL)
and water (100 mL). The organic layer was washed
with water (100 mL) and the combined aqueous layers
were re-extracted with CH2Cl2 (100 mL). The combined
organic layers were dried (MgSO4), filtered and concen-
trated. The residue thus obtained was subjected to flash
chromatography (eluent 15:1 CHCl3–Me2CO) to give
13 (480 mg, 43%); Rf 0.45 (10:1 CHCl3–Me2CO); mp
42–43 °C (i-PrOH); [h]D +34.6° (c 2.8, CHCl3); 1H
NMR (CDCl3; 270 MHz): l 7.34–7.28 (m, 5 H, Ph),
7.27–7.24 (m, 2 H, ortho-H of PMB), 6.92–6.86 (m, 2
H, meta-H of PMB), 4.88 (d, 1 H, J1,2 0.5 Hz, H-1),
A sample of 11 was converted into its acetate 12 with
Ac2O in pyridine; Rf 0.5 (10:1 CHCl3–Me2CO); [h]D
1
+21.5° (c 1.2, CHCl3); H NMR (CDCl3; 270 MHz): l
7.34–7.25 (m, 5 H, Ph), 7.22–7.14 (m, ortho-H of
PMB), 6.85–6.79 (m, 2 H, meta-H of PMB), 5.18 (d, 1
H, J2,3 4.4 Hz, H-2), 4.87 (s, 1 H, H-1), 4.57, 4.54 (AB,
2 H, JAB 12.3 Hz, ArCH2O), 4.51, 4.34 (AB, 2 H, JAB
11.1 Hz, ArCH2O), 4.20 (1 H, ddd, J4,3 7.7, J4,5b 5.7,
J4,5a 3.6 Hz, H-4), 4.11 (dd, 1 H, H-3), 3.77 (s, 3 H,
ArOMe), 3.59 (dd, 1 H, J5a,5b 10.7 Hz, H-5a), 3.48 (dd,
1 H, H-5b), 3.33 (s, 3 H, OMe), 2.12 (s, 3 H, MeCO2);
FABMS (positive ion): m/z 416 ([M+], 30%), 121 (100).

A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
1075
Anal. Calcd for C23H28O7: C, 66.32; H, 6.78. Found: C,
66.1; H, 6.82.
Regeneration of 10ab.—DDQ (591 mg, 2.6 mmol)
was added to a solution of 11 (811 mg, 2.2 mmol) in
(CꢁNH), 159.20 (para-C of PMB), 138.11, 138.02 (ipso-
C of Bn), 130.63, 130.19 (ipso-C of PMB), 129.64,
129.46, 128.47, 128.36, 127.93, 127.89, 127.76, 127.61
(ArCH), 113.79, (meta-C of PMB), 98.35 (C-1), 75.90,
77.03, 81.00, 84.29 (C-2–C-5), 75.32, 74.91, 74.60, 73.35
(4×OCH2Ar), 68.21 (C-6), 55.27 (2×OCH3); FABMS
(negative ion): m/z 744 ([M−H]−, 34%), 311 (73), 188
(100). Anal. Calcd for C38H40N1O8Cl3: C, 61.26; H,
5.41; N, 1.88. Found: C, 61.4; H, 5.41; N 1.86.
Further elution gave the syrupy a-anomer 17a (0.25
g, 20%); [h]D +13.6° (c 1.3, CHCl3); 1H NMR (CDCl3;
270 MHz): l 8.57 (s, 1 H, CꢁNH), 7.32–7.23 (m, 12 H,
ArCH), 7.08–7.05 (m, 2 H, ortho-H of PMB), 6.85–
6.79 (m, 4 H, meta-H of PMB), 6.51 (d, 1 H, J1,2 3.3
Hz, H-1), 4.87, 4.76 (AB, 2 H, JAB 10.4 Hz, OCH2Ar),
4.74, 4.69 (AB, 2 H, JAB 11.7 Hz, OCH2Ar), 4.60, 4.47
(AB, 2 H, JAB 12.1 Hz, OCH2Ar), 4.77, 4.45 (AB, 2 H,
JAB 10.3 Hz, OCH2Ar), 4.06–3.94 (m, 2 H, H-3, H-5),
3.79, 3.78 (2 s, 6 H, 2×OCH3), 3.80–3.71 (m, 3 H,
H-2, H-4, H-6a), 3.65 (dd, 1 H, J6b,6a 10.9, J6b,5 1.9 Hz,
H-6b); 13C NMR (CDCl3; 100 MHz): l 161.32 (s,
CꢁNH), 159.31, 159.12 (para-C of PMB), 138.04,
137.91 (ipso-C of Bn), 130.85, 130.28 (ipso-C of PMB),
129.74, 129.68, 128.36, 127.94, 127.69, 127.59 (ArCH),
113.83, 113.77 (meta-C of PMB), 94.42 (C-1), 81.07,
79.43, 76.50, 73.17 (C-2ꢀC-5), 75.31, 74.94, 73.46, 72.88
(OCH2Ar), 68.03 (C-6), 55.27 (2×OCH3); FABMS
(negative ion): m/z 744 ([M−H]−, 1%), 121 (100). A
satisfactory elemental analysis could not be obtained
for this compound.
,
dry CH2Cl2 (5 mL) containing freshly activated 3 A
molecular sieves. The mixture, which rapidly turned
black, was stirred at rt for 3 h, when TLC (10:1
CHCl3–Me2CO) indicated consumption of starting ma-
terial (Rf 0.3) to give a product (Rf 0.6). 10% w/v aq
Na2SO3 (50 mL) and CH2Cl2 (100 mL) were added and
the mixture was stirred vigorously for 10 min. The
organic layer was collected and washed with satd aq
NaHCO3 (2×100 mL) and satd aq NaCl (100 mL),
dried (MgSO4), filtered and concentrated. Flash chro-
matography (eluent 19:1 hexane–EtOAc then 7:3) gave
1
acetal 10ab, which was shown by H NMR to be a 92:8
diastereoisomeric mixture (569 mg, 71%); [h]D −26.4°
(c 3.3, CHCl3).
Methyl 5-O-benzyl-i- -ribofuranoside (15).—A solu-
D
tion of acetal 10 (216 mg, 0.6 mmol) in 80% v/v aq
AcOH (preheated to 60 °C, 23 mL) was stirred at 60 °C
for 25 min, then rapidly cooled (ice-bath). Toluene (50
mL) was added and the mixture was evaporated to
dryness. The orange syrup thus obtained was subjected
to flash chromatography (eluent 9:1 hexane–EtOAc to
remove p-methoxybenzaldehyde then 1:4) to give the
title compound as a pale yellow syrup, which TLC (cf.
23) and 1H NMR showed to be exclusively the b
anomer (125 mg, 85%); [h]D −42.0° (c 4.9, CHCl3)
lit.23 −47.7°.
2,6-Di-O-benzyl-3,4-di-O-p-methoxybenzyl-i-
glucopyranosyl trichloroacetimidate (17b) and 2,6-di-O-
benzyl-3,4-di-O -p-methoxybenzyl-h- -glucopyranosyl
D-
Methyl
2%,5,6%-tri-O-benzyl-3-O-
D
-glucopyranosyl-
- ribofuranosides
2,3%,4% - tri - O - p - methoxybenzyl - i -
D
D
(18ab).—A mixture of 17b (188 mg, 0.25 mmol), and
13 (86 mg, 0.23 mmol) was stirred in dry ether (2.5 mL)
trichloroacetimidate (17a).—To a solution of 1610 (1.00
g, 1.67mmol) in freshly distilled, dry CH2Cl2 (10 mL)
was added freshly flame-dried K2CO3 (1.00 g, 7.25
mmol), followed by freshly distilled trichloroacetonitrile
(1.00 mL). The mixture was left to stir at rt under an
atmosphere of nitrogen for 140 min, after which time
TLC (30:1 CHCl3–Me2CO) indicated a small amount
of starting material (Rf 0.14), a major product (Rf 0.47)
and a minor product (Rf 0.58). The reaction mixture
was filtered through a pad of Celite and concentrated to
a colourless oil. This oil was purified by flash chro-
matography (eluent 50:1 CHCl3–Me2CO), to give the b
anomer 17b (0.59 g, 48%), which was crystallised from
a minimum volume of 1:1 ether–petroleum ether at
,
at rt with 4 A molecular sieves (90 mg) for 30 min,
whereupon trimethylsilyl triflate (0.01 mL of a 0.2 M
solution in ether, 2 nmol) was added. After 5 min TLC
(30:1 CHCl3–Me2CO) showed formation of a product
(Rf 0.26) from the imidate (Rf 0.32), and the glycosyl
acceptor (Rf 0.23). The reaction was quenched with
Et3N (6 drops), and the mixture was concentrated. The
resulting clear oil was subjected to flash chromatogra-
phy (eluent 30:1 CHCl3–Me2CO), and again (eluent
35:1 CHCl3–Me2CO), to give an inseparable glucopy-
ranosyl anomeric mixture of the title compound in a 4:1
1
a:b anomeric ratio, as calculated from H NMR inte-
1
1
gral ratios (120 mg, 54%); Selected H NMR data for
−4 °C; mp 80–81 °C; [h]D +16.5° (c 4.7, CHCl3); H
a-coupled product: 1H NMR (400 MHz; CDCl3): l
5.09 (d, 1 H, J1%,2% 3.4 Hz, H-1%), 4.93 (d, 1 H, J1,2 2.0
Hz, H-1); FABMS (negative ion): m/z 1109 ([M+
NBA]−, 100%). Anal Calcd for C57H64O13: C, 71.53; H,
6.74. Found: C, 71.5; H, 6.72.
NMR (CDCl3; 270 MHz): l 8.69 (s, 1 H, CꢁNH),
7.31–7.20 (m, 12 H, Ar), 7.09 (m, 2 H, ortho-H of
PMB), 6.85–6.79 (m, 4 H, meta-H of PMB), 5.78 (d, 1
H, J1,2 8.3 Hz, H-1), 4.93 (AB, 1 H, JAB 11.0 Hz,
OCHHAr), 4.82 (AB, 1 H, JAB 10.4 Hz, OCHHAr),
4.78–4.47 (m, 6 H, 3×OCH2Ar), 3.80, 3.79 (2 s, 6 H,
2×OCH3), 3.73–3.56 (m, 6 H, H-2, H-3, H-4, H-5,
H-6a, H-6b); 13C NMR (CDCl3; 100.4 MHz): l 161.23
Methyl 2%,5,6%-tri-O-benzyl-3-O-i-
i- -ribofuranoside (19b) and methyl 2%,5,6%-tri-O-ben-
zyl-3-O-h- -glucopyranosyl-i- -ribofuranoside (19a).
D-glucopyranosyl-
D
D
D

1076
A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
—A solution of 18ab (379 mg, 0.40 mmol) in CH2Cl2
(12 mL) and water (1 mL) was stirred for 20 min,
whereupon DDQ (551 mg, 2.38 mmol) was added.
After 60 min TLC (30:1 CHCl3–Me2CO) showed con-
sumption of starting material (Rf 0.26). The reaction
mixture was diluted with CH2Cl2 (60 mL), and the
organic layer washed with aq 10% w/v Na2SO3 (3×50
mL), followed by 50 mL each of satd aq NaHCO3 and
satd aq NaCl. The organic layer was dried (MgSO4)
filtered and concentrated to give a clear oil, which was
subjected to flash chromatography (eluent 7:3 EtOAc–
The system was cooled to −78 °C, MCPBA (432 mg,
2.15 mmol) was added, the cooling bath was removed,
and the mixture was allowed to warm to rt. The
mixture was diluted with CH2Cl2 (100 mL) and the
organic extract was separated and washed with 10% aq
Na2SO3 (50 mL), satd aq NaHCO3 (2×50 mL), and
satd aq NaCl (50 mL). The organic solution was dried
(MgSO4), filtered and concentrated to give a white solid
which was purified by flash chromatography (eluent
20:1 CHCl3–Me2CO then 10:1, then 4:1) to give the
title compound as a colourless oil (220 mg, 89%); [h]D
1
1
hexane), to give the b anomer 19b (27 mg, 11%); H
+34.7° (c 8.07, CHCl3); H NMR (CDCl3; 400 MHz):
NMR (CDCl3; 400 MHz): l 7.35–7.23 (m, 15 H,
ArCH), 4.90 (s, 1 H, H-1), 4.81, 4.58 (AB, 2 H, JAB
11.5 Hz, OCH2Ar), 4.54–4.50 (m, 4 H, 2×OCH2Ar),
4.45 (d, 1 H, J1%,2% 7.8 Hz, H-1%), 4.33–4.28 (m, 1 H,
H-4), 4.18 (dd, 1 H, J3,4 6.8, J3,2 4.4 Hz, H-3), 4.11 (d,
1 H, H-2), 3.70 (dd, 1 H, J6%a,6%b 10.5, J6%a,5 3.2 Hz,
H-6%a), 3.63–3.59 (m, 2 H, H-5a, H-6%b), 3.56 (dd, 1 H,
J5b,5a 10.5, J5b,4 5.6 Hz, H-5b), 3.49–3.40 (m, 3 H, H-3%,
H-4%, H-5%), 3.33 (s, 3 H, OCH3), 3.27–3.23 (m, 1 H,
H-2%), 3.06, 2.86, 2.30 (3×br. s, 3 H, 3×OH).
Further elution gave the a anomer 19a (135 mg,
57%), which crystallised spontaneously on standing; mp
103–105 °C; [h]D +28.3° (c 3.7, CHCl3); 1H NMR
(CDCl3; 400 MHz): l 7.36–7.23 (m, 15 H, ArCH), 4.88
(s, 1 H, H-1), 4.74, 4.69 (AB, 2 H, J 11.7 Hz, OCH2Ar),
4.69 (d, 1 H, J1%,2% 3.4 Hz, H-1%), 4.51 (s, 2 H, OCH2Ar),
4.52, 4.44 (AB, 2 H, JAB 12.2 Hz, OCH2Ar), 4.22 (m, 2
H, H-2, H-4), 4.01 (m, 1 H, H-3), 3.92 (t, 1 H,
J3%2%=J3%,4%=9.3 Hz, H-3%), 3.74 (dt, 1 H, J5%,4% 9.8, J5%,6%a
3.9, J5%,6%b 3.9 Hz, H-5%), 3.57–3.45 (m, 5 H, H-4%, H-5a,
H-5b, H-6%a, H-6%b), 3.38 (dd, 1 H, H-2%), 3.32 (s, 3 H,
OCH3), 2.87, 2.74 (2 br s, 2 H, D2O exch, OH), 1.69 (br
s, 1 H, D2O exch, OH); 13C NMR (CDCl3; 100 MHz):
l 138.06, 137.86, 137.18 (ipso-C of Bn), 128.75, 128.51,
128.42, 128.33, 127.74, 127.69, 127.63, 127.57 (ArCH),
108.34 (C-1), 97.79 (C-1%), 80.27 (C-2 or C-4), 79.11
(C-2 or C-4), 78.35 (C-2%), 74.14, 73.55, 73.32
(OCH2Ar), 73.28 (C-3), 73.24 (C-3%), 71.69 (C-5 or
C-6%), 70.84 (C-5%), 70.74 (C-4%), 69.00 (C-5 or C-6%),
55.03 (OCH3); FABMS (positive ion): m/z 597 ([M+
1]+, 12%), 565 (48), 343 (3), 255 (2). HRFABMS
(positive ion): Calcd for C33H40O10 [M+]: 596.262.
Found: 596.259.
l 7.35–7.01 (m, 45 H, ArCH), 5.09 (d, 1 H, J1%,2% 3.4
Hz, H-1%), 5.03–4.80 (m, 13 H, H-1, H-3%, 11×
OCH2Ar), 4.77–4.67 (m, 3 H, 2×OCH2Ar, H-2), 4.60
(q, 1 H, J4%,3%:J4%,5%:JHP:9.5 Hz, H-4%), 4.53–4.34
(m, 5 H, 4×OCH2Ar, H-3), 4.31–4.28 (AB, 2 H, JAB
11.7 Hz, OCHHAr overlapping with H-4), 3.84–3.82
(m, 1 H, H-5%), 3.65 (ABX, 2 H, JAB 10.4, J6%a,5%
=
J6%b,5%=3.9 Hz, H-6%a and H-6%b), 3.60–3.55 (m, 2 H,
H-2%, H-5a), 3.52 (dd, 1 H, J5b,5a 10.5, J5b,4 5.1 Hz,
H-5b), 3.25 (s, 3 H, OCH3); 31P NMR (CDCl3; 162
1
MHz; H decoupled) l −1.22, −1.94, −2.25 (3 s);
FABMS (positive ion): m/z 1377 ([M+], 4%), 91 (100).
HRFABMS (positive ion): Calcd for C75H80O19P3
[M+]: 1377.450. Found: 1377.451.
Methyl 3-O-h-D-glucopyranosyl-i-D-ribofuranoside
2,3%,4%-trisphosphate (4).—10% palladium on activated
charcoal (200 mg), was added to a solution of 20 in
MeOH (40 mL) and water (10 mL). This mixture was
shaken under 40 psi pressure in an atmosphere of H2
for 18 h, after which it was filtered through Celite. The
filtrate was concentrated to a glassy clear solid. The
residue was dissolved in de-ionised water (300 mL) and
purified by ion-exchange chromatography on Q Sepa-
rose Fast Flow resin, eluting with a gradient of TEAB
buffer (0–1 M), pH 7.5. The triethylammonium salt of
the title compound eluted over 800–850 mM buffer.
After concentration of the appropriate fractions, the
triethylammonium salt of 4 was found to have very low
solubility in water. Therefore 4 was converted into its
potassium salt with 0.1 M aq KOH (2 mL), and
subsequently quantified by a modification of the Briggs
total phosphate assay39 (60 mmol, 78%); [h]D +79.1° (c
1
1.70 calculated for free acid, MeOH); H NMR (tri-
Methyl 2%,5,6%-tri-O-benzyl-3-O-h-
2,3%,4%-tris-O-(dibenzyloxyphosphoryl)-i-
D
-glucopyranosyl-
-ribofurano-
ethylammonium salt, CD3OD; 400 MHz): l 5.13 (d, 1
H, J1%,2% 3.7 Hz, H-1%), 4.94 (s, 1 H, H-1), 4.58 (dd, 1 H,
D
side (20).—A mixture of bis(benzyloxy)-(diisopropy-
lamino)phosphine (372 mg, 1.08 mmol), dry CH2Cl2 (3
mL) and 1H-tetrazole (113 mg, 1.62 mmol) was stirred
at rt for 30 min, whereupon a solution of 19a (107 mg,
0.18 mmol) in dry CH2Cl2 (2 mL) was added and
stirring was continued for a further 30 min. TLC (7:3
EtOAc–hexane) indicated complete conversion of start-
ing material (Rf 0.14) into a product (Rf 0.49), and 31P
NMR spectroscopy showed phosphite triester signals.
JHP 9.5, J2,3 4.3 Hz, H-2), 4.45 (q, 1 H, J3%,2%:J3%,4%:
JHP:9 Hz, H-3%), 4.44 (dd, 1 H, J3,4 7.3 Hz, H-3),
4.11–4.04 (m, 2 H, H-4, H-4%), 3.93 (ABX, 1 H, J6%a,6%b
13.0, J6%a,5 3.5 Hz, H-6%a), 3.73–3.69 (m, 3 H, H-5a,
H-5%, H-6%b), 3.62 (dd, 1 H, H-2%), 3.54 (ABX, 1 H,
J5b,5a 11.9, J5b,4 6.4, Hz, H-5b), 3.35 (s, 3 H, OCH3); 13
C
NMR (CDCl3; 100 MHz): l 108.96 (3JCP 3.7, C-1),
98.93 (C-1%), 82.71 (C-4), 78.83, 76.46, 76.29, 73.78,
73.52, 73.32 (C-2, C-3, C-2%ꢀC-5%), 64.87, 61.98 (C-5,

A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
1077
1
C-6%), 55.18 (OCH3); 31P NMR (CD3OD; 162 MHz; H
decoupled) lP 1.10, 1.05, −0.38, (3 s); FABMS (nega-
tive ion): m/z 565 ([M−H]− 100%); HRFABMS (neg-
ative ion): Calcd for C12H24O19P3 [M−H]−: 565.012.
Found: 565.012.
(3S,4R)-3-[(−)-Camphanoyloxy]-4-(p-methoxybenz-
yloxy)-tetrahydrofuran (23) and (3R,4S)-3-[(−)-cam-
phanoyloxy] - 4 - (p - methoxybenzyloxy) - tetrahydrofuran
(24).—To a stirred solution of the racemic alcohol
(9)-22 (7.0 g, 31.2 mmol) in anhyd pyridine (60 mL) at
0 °C was added (−)-(S)-camphanic chloride (8.0 g,
36.9 mmol). After 5 min, the cooling bath was removed
and the mixture was stirred for a further 1 h, after
which time TLC (ether) showed complete conversion of
starting material (Rf 0.32) into two products (Rf 0.40
and 0.48). Excess camphanic chloride was destroyed by
addition of water (10 mL) and the solvents were re-
moved by evaporation under reduced pressure. The
residue was taken up in Et2O (200 mL) and water (200
mL). The organic layer was separated and washed
sequentially with 1 M HCl and satd aq NaHCO3 (200
mL of each), dried (MgSO4) and concentrated by evap-
oration under reduced pressure to give an oil. The
diastereoisomers were separated by flash chromatogra-
phy (2:1 Et2O–pentane) followed by crystallisation.
The less polar diastereoisomer 24 was crystallised
from Et2O (5.09 g, 12.6 mmol, 80% of this diastereoiso-
mer); mp 67–68 °C; Rf 0.24 (2:1 Et2O–pentane); [h]D
cis - 4 - (p - Methoxybenzyloxy) - tetrahydrofuran - 3 - ol
[(9)-22].—To a solution of 1,4-anhydroerythritol (21)
(10.4 g, 100 mmol) in dry DMF (100 mL) in a 250 mL
round bottom flask was added p-methoxbenzaldehyde
dimethyl acetal (19.1 g, 105 mmol) and a catalytic
amount of PTSA (100 mg). The flask was fitted with a
250 mm air condenser connected to a filter pump and
the solution was stirred at 70 °C under reduced pressure
for 3 h, after which time TLC (Et2O) showed the
reaction to be complete, with complete conversion of
starting material into two products (Rf 0.52 and 0.58).
Excess NaHCO3 (500 mg) was added and the mixture
was allowed to cool. The solvents were removed by
evaporation under reduced pressure and the oily residue
was taken up in Et2O (500 mL), washed with water (300
mL), and dried (MgSO4). A few drops of Et3N were
added, and the solution was concentrated by evapora-
tion under reduced pressure to give the crude mixture
of epimeric acetals as a yellow oil (23.0 g). A portion of
this product (8.10 g) was dissolved in dry CH2Cl2 (100
mL) and stirred at −78 °C under N2. A solution of
DIBAL–H (90 mL of a 1.0 M solution in CH2Cl2, 90
mmol) was added dropwise over 15 min. After 4 h,
TLC (1:1 EtOAc–hexane) showed the reaction to be
almost complete with conversion of the two epimeric
acetals into a single, more polar product (Rf 0.26). The
cooling bath was removed, and after a further 45 min
the mixture was poured into a rapidly stirring mixture
of EtOH (20 mL) and CH2Cl2 (200 mL) at 0 °C
[CARE! FIZZING!]. NaOH (0.5 M, 300 mL) was
added and stirring continued to dissolve the gelatinous
material that had formed. The organic layer was re-
moved and the aqueous layer was extracted with
CH2Cl2 (2×300 mL). The combined organic extracts
were dried (MgSO4) and concentrated by evaporation
under reduced pressure to give an oil. Purification by
flash chromatography (2:3 EtOAc–hexane) gave the
racemic alcohol (9)-22 as a colourless oil (7.12 g, 31.7
mmol, 90% yield from 21); 1H NMR (CDCl3, 400
MHz) l 7.28–7.25 (m, 2 H, ortho-H of PMB), 6.92–
6.88 (m, 2 H, meta-H of PMB), 4.55, 4.53 (AB, 2 H,
JAB 11.3 Hz, OCH2Ar), 4.25–4.20 (m, 1 H, H-3), 4.05
(q, 1 H, J4,3:J4,5a:J4,5b:5.5 Hz, H-4), 3.90–3.86 (m,
2 H, H-2a and H-5a), 3.81 (s, 3 H. ArOCH3), 3.77–3.72
(m, 2 H, H-2b and H-5b), 2.79 (d, 1 H, J 5.5 Hz, D2O
exch, 3-OH); 13C NMR (CDCl3, 100 MHz) l 159.62
(para-C of PMB), 129.63 (ortho-C of PMB), 129.24
(ipso-C of PMB), 114.03 (meta-C of PMB), 78.00 (C-4),
73.48 (CH2), 72.33 (CH2), 70.28 (C-3), 70.03 (CH2),
55.30 (ArOCH3); FABMS (positive ion): m/z 224 ([M+
], 20%); 121 (100).
1
−41° (c 1, CHCl3); H NMR (CDCl3, 270 MHz) l
7.26–7.21 (m, 2 H, ortho-H of PMB), 6.90–6.85 (m, 2
H, meta-H of PMB), 5.47 (dt, 1 H, J3,4 4.8, J3,2a 4.8,
J3,2b 2.6 Hz, H-3), 4.54, 4.43 (AB, 2 H, JAB 11.2 Hz,
OCH2Ar), 4.20 (dt, 1 H, J4,5b 7.5, J4,5a 4.9 Hz, H-4),
4.09 (dd, 1 H, J2a,2b 10.8 Hz, H-2a), 3.98–3.92 (m, 2 H,
H-2b and H-5a), 3.80 (s, 3 H, ArOCH3), 3.66 (dd, 1 H,
J5b,5a 8.3 Hz, H-5b), 2.48–2.37 (m, 1 H, camph CH2),
2.02–1.84 (m, 2 H, camph CH2), 1.72–1.60 (m, 1 H,
camph CH2), 1.10 (s, 3 H, camph CH3), 0.99 (s, 3 H,
camph CH3), 0.96 (s, 3 H, camph CH3); 13C NMR
(CDCl3, 68 MHz) l 178.15 (CꢁO), 166.94 (CꢁO),
159.44 (para-C of PMB), 129.56 (ortho-C of PMB),
129.40 (ipso-C of PMB), 113.82 (meta-C of PMB),
91.18 (camph quaternary C), 77.20 (C-4), 72.74 (C-3),
72.62 (OCH2Ar), 71.05 (CH2), 69.31 (CH2), 55.29
(ArOCH3), 54.91 (camph quaternary C), 54.19 (camph
quaternary C), 30.77 (camph CH2), 28.85 (camph CH2),
16.70 (camph CH3), 16.59 (camph CH3), 9.70 (camph
CH3); FABMS (positive ion): m/z 426 ([M+Na]+,
40%), 404 ([M+], 100%); FABMS (negative ion): 197
[(camphO)−, 100%]; (camph=camphanoyl); Anal.
Calcd for C22H28O7: C, 65.33; H 6.98, Found C, 65.5;
H, 7.09.
The more polar diastereoisomer 23 was crystallised
from diisopropyl ether; (5.21 g, 12.9 mmol, 82% of this
diastereoisomer) mp 81–83 °C; Rf 0.18 (2:1 Et2O–pen-
1
tane); [h]D +27° (c 1, CHCl3); H NMR (CDCl3, 270
MHz) l 7.28–7.22 (m, 2 H, ortho-H of PMB), 6.89–
6.84 (m, meta-H of PMB), 5.50 (dt, 1 H, J3,4 4.8, J3,2a
4.8, J3,2b 2.6 Hz, H-3), 4.57, 4.44 (AB, 2 H, JAB 11.5
Hz, OCH2Ar), 4.22–4.15 (m, 1 H, H-4), 4.09 (dd, 1 H,
J2a,2b 10.6 Hz, H-2a), 3.97–3.90 (m, 2 H, H-2b and

1078
A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
H-5a), 3.80 (s, 3 H, ArOCH3), 3.66 (dd, 1 H, J5b,5a 8.4,
J5b,4 8.1 Hz, H-5b), 2.46–2.35 (m, 1 H, camph CH2),
2.07–1.86 (m, 2 H, camph CH2), 1.74–1.64 (m, 1 H,
camph CH2), 1.10 (s, 3 H, camph CH3), 1.05 (s, 3 H,
camph CH3), 0.89 (s, 3 H, camph CH3); 13C NMR
(CDCl3, 68 MHz) l 178.04 (CꢁO), 166.75 (CꢁO),
159.44 (para-C of PMB), 129.58 (ortho-C of PMB),
129.37 (ipso-C of PMB), 113.80 (meta-C of PMB),
91.09 (camph quaternary C), 76.99 (C-4), 72.64 (C-3),
72.59 (CH2), 71.02 (CH2), 69.23 (CH2), 55.29
(ArOCH3), 54.85 (camph quaternary C), 54.20 (camph
quaternary C), 30.73 (camph CH2), 28.95 (camph CH2),
16.59 (camph CH3), 16.36 (camph CH3), 9.68 (camph
CH3); FABMS (positive ion): m/z 426 ([M+Na]+,
55%), 404 ([M+], 100%); (camph=camphanoyl); Anal.
Calcd for C22H28O7: C, 65.33; H 6.98, Found C, 65.5;
H, 7.00.
(3R,4S) - 4 - (p - Methoxybenzyloxy) - tetrahydrofuran -
3-ol [(+)-22].—To a solution of the camphanate ester
24 (3.10 g, 7.66 mmol) in MeOH (100 mL) were added
NaOH pellets (2.0 g, 50 mmol). The mixture was heated
at reflux for 1 h and then allowed to cool. The NaOH
was neutralised by careful addition of solid CO2, and
water (100 mL) was added. The MeOH was removed
by evaporation under reduced pressure and the remain-
ing aqueous solution was extracted with CH2Cl2 (3×
100 mL). The combined extracts were dried (MgSO4)
and concentrated by evaporation under reduced pres-
sure to give an oil which slowly crystallised. Crystallisa-
tion from Et2O at −20 °C gave pure (+)-22 as
colourless needles (1.62 g, 7.22 mmol, 94% yield); mp
53–54.5 °C; [h]D +13° (c 1, CHCl3); Anal. Calcd for
C12H16O4: C, 64.29; H 7.19, Found C, 64.6; H, 7.21.
Spectroscopic data were identical to those for (9)-2.
(3S,4R) - 4 - (p - Methoxybenzyloxy) - tetrahydrofuran-
3-ol [(−)-22].—Saponification of 23 (2.20 g, 5.43
mmol) and crystallisation as described for 24 gave
(−)-22 as colourless needles (1.18 g, 5.26 mmol, 97%
yield); mp 53–54.5 °C; [h]D −13° (c 1, CHCl3); Anal.
Calcd for C12H16O4: C, 64.29; H 7.19, Found C, 64.4;
H, 7.17. Spectroscopic data were identical to those for
(9)-22.
were removed by evaporation under reduced pressure
and the residue was taken up in CH2Cl2 (50 mL),
washed with satd aq NaHCO3 (50 mL), dried (MgSO4)
and concentrated to give a yellow oil which was
purified by flash chromatography (eluent 4:1 Et2O–hex-
ane) yielding 25 as a colourless liquid [336 mg, 1.73
mmol, 87% yield from (−)-22]; [h]D −26.5° (c 1,
MeOH); Lit.28 +27.52° for the enantiomer. Spectro-
scopic data were identical to those reported for the
enantiomer.28
(3%S,4%R) - 3% - (p - Methoxybenzyloxy)tetrahydrofuran -
4%-yl
2,6-di-O-benzyl-3,4-di-O-p-methoxybenzyl-h-D-
glucopyranoside (28).—A mixture of 26ab8 (1.85 g, 2.68
,
mmol), (+)-22 (0.30 g, 1.34 mmol) and 4 A molecular
sieves (1.50 g) in toluene (5 mL) and dioxane (15 mL)
was stirred for 2 h under an atmosphere of N2. ZnCl2
(0.44 g) and AgClO4 (1.33 g) were added and the flask
was wrapped in foil. After a further 2 h TLC (1:4
EtOAc–toluene) indicated the formation of one major
product (Rf 0.44). The foil was removed, water (25 mL)
was added, the resulting pale pink suspension was
filtered through Celite and the residue was well washed
with EtOAc. The filtrate and washings were transferred
to a separating funnel containing EtOAc (150 mL) and
water (100 mL). The organic layer was washed with
satd aq NaCl (100 mL), dried (MgSO4), filtered and
concentrated. The residue was subjected to flash chro-
matography (eluent 1:9 EtOAc–toluene) yielding the
title compound as a colourless oil which solidified on
standing (0.82 g, 76%); mp 80–83 °C (Et2O–hexane);
[h]D +19.0° (c 0.2, CHCl3); 1H NMR (CDCl3; 400
MHz): l 7.32–7.21 (m, 14 H, ArCH), 7.05–7.02 (m, 2
H, ortho-H of PMB), 6.83–6.77 (m, 6 H, meta-H of
PMB), 5.18 (d, 1 H, J1,2 3.4 Hz, H-1), 4.89–4.36 (m, 10
H, 5×OCH2Ar), 4.20 (q, 1 H, J4%,3%:J4%,5%a:J4%,5%b
:
5.5 Hz, H-4%), 4.07 (q, 1 H, J3%,2%a:J3,2%b:5.5 Hz, H-3%),
4.02–3.93 (m, 3 H, H-2%a, H-3, H-5%a), 3.87–3.68 (m,
13 H, 3×OCH3, H-2%b, H-5, H-5%b, H-6a), 3.62–3.54
(m, 3 H, H-2, H-4, H-6b); 13C NMR (CDCl3; 100
MHz): l 159.17, 159.13, 159.06 (para-C of PMB),
138.34, 137.83 (ipso-C of Bn), 130.99, 130.36, 130.09
(ipso-C of PMB) 129.54, 129.47,128.32, 128.23, 127.84,
127.73, 127.64, 127.51 (ArCH), 113.69 (meta-C of
PMB), 96.90 (C-1), 81.33 (C-3), 79.74 (C-2), 77.33
(C-3%), 77.17 (C-4), 75.94 (C-4%), 75.24, 74.64, 73.38,
72.30, 72.01 (OCH2Ar), 70.67 (C-5), 70.45 (C-2%, or
C-5%), 70.23 (C-2%, or C-5%), 68.33 (C-6), 55.18, 55.17
(2×OCH3); FABMS (positive ion): m/z 829 ([M+
Na]+, 3%); 121 (100). Anal Calcd for C48H54O11: C,
71.45; H, 6.74. Found: C, 71.3; H, 6.75.
Determination of absolute configuration of (−)-22.—
To a solution of the alcohol (−)-22 (449 mg, 2.00
mmol) in dry DMF (10 mL) was added NaH (80 mg of
a 60% dispersion in mineral oil, 4.0 mmol) followed by
benzyl bromide (0.30 mL, 2.5 mmol). The mixture was
stirred overnight at rt and then water (2 mL) was
carefully added to destroy excess NaH. The solvents
were removed by evaporation under reduced pressure
and the residue was taken up in Et2O (50 mL), washed
with water (50 mL), dried (MgSO4) and concentrated
by evaporation under reduced pressure to give an oil.
Dry CH2Cl2 (9 mL) was added followed by TFA (1
mL), and after 1 h at rt, TLC (ether) showed total
conversion into a single product (Rf 0.26). The solvents
(3%S,4%R)-3%-Hydroxytetrahydrofuran-4%-yl 2,6-di-O-
benzyl-h- -glucopyranoside (28).—Trifluoroacetic acid
D
(2 mL) was added to a solution of 27 (500 mg, 0.62
mmol) in CH2Cl2 (18 mL). The resulting purple solu-
tion was stirred at rt for 10 min and then poured slowly
into satd aq NaHCO3 (300 mL). The aqueous layer was

A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
1079
extracted with CH2Cl2 (3×100 mL) and the combined
organic layer was dried (MgSO4), filtered and concen-
trated, leaving a yellow oil which was subjected to flash
chromatography (eluent 7:3 EtOAc–hexane), to give
the title compound as a white solid (234 mg, 84%); mp
83–85 °C (Et2O); [h]D +70.0° (c 0.4, CHCl3); 1H
NMR (CDCl3; 400 MHz): l 7.36–7.22 (m, 10 H, Ph),
4.75 (d, 1 H, J1,2 3.7 Hz, H-1), 4.76, 4.63 (AB, 2 H, JAB
11.7 Hz, OCH2Ph), 4.53, 4.49, (AB, 2 H, JAB 12.2 Hz,
OCH2Ph), 4.44 (br s, 1 H, D2O exch, 3-OH), 4.23–4.17
(m, 1 H, H-3%), 4.11–4.07 (m, 2 H, D2O exch, 3%-OH,
4-OH), 3.99 (q, 1 H, J4%,3%:J4%,5%a:J4%,5%b:5.4 Hz, H-
4%), 3.93 (dt, 1 H, J3,4 9.0, J3,2 9.0, J3,OH 3.9 Hz, H-3),
3.90–3.82 (m, 2 H, H-2%a, H-5%a), 3.79–3.74 (m, 2 H,
H-5, H-5%b), 3.69 (dd, 1 H, J2%b,2%a 9.8, J2%b,3% 4.4 Hz,
H-2%b), 3.65–3.60 (m, 2 H, H-6a, H-6b), 3.47 (dt, 1 H,
J4,5 9.3, J4,OH 3.9 Hz, H-4), 3.37 (dd, 1 H, J2,3 9.5, H-2);
13C NMR (CDCl3; 100.4 MHz): d 137.75, 137.11 (ipso-
C of Bn), 128.48, 128.33, 128.19, 127.46, 127.42 (Ph),
98.4 (C-1), 78.90 (C-4%), 78.81 (C-2), 73.93, 73.32
(OCH2Ar), 72.92 (C-3), 72.48 (C-5%), 71.08 (C-5), 70.60
(C-3%), 70.31 (C-2%), 70.23 (C-4), 68.94 (C-6); FABMS
(positive ion): m/z 829 ([M+Na]+, 3%), 121 (100);
Anal Calcd for C24H30O8: C, 64.56; H, 6.77. Found: C
64.4; H 6.78.
(3%S,4%R)-3%-Hydroxytetrahydrofuran-4%-yl h-
D
-glu-
copyranoside 3,3%,4-trisphosphate (5).—Moist palla-
dium on carbon 10% (200 mg) was added to a solution
of 29 (75 mg, 61 mmol) in MeOH (50 mL) and water
(10 mL). This mixture was shaken in an atmosphere of
H2 at 50 psi for 25 h. The catalyst was removed by
filtration through a PTFE membrane filter, and the
filtrate was concentrated to a clear residue. The crude
product was purified by ion exchange chromatography
on Q Separose Fast Flow resin, eluting with a gradient
of TEAB buffer (0–1 M), pH 8.0. The triethylammo-
nium salt of the title compound eluted between 560–
620 mM buffer (57 mmol, 93%); [h]D +74.8° (c 0.6
1
calculated for free acid, MeOH); H NMR (D2O; 400
MHz) l 5.25 (d, 1 H, J1,2 3.2 Hz, H-1), 4.89–4.80 (m,
1 H, H-3%), 4.50–4.43 (m, 2 H, H-3, H-4%), 4.09–4.01
(m, 3 H, H-2%a, H-4, H-5%a), 3.94–3.78 (m, 5 H, H-2%b,
H-5, H-5%b, H-6a, H-6b), 3.74 (dd, 1 H, J2,3 9.0, H-2);
1
31P NMR (CD3OD; 162 MHz; H-coupled): l 1.08 (d,
JHP 9.8 Hz), 0.82 (d, JHP 7.6 Hz), 0.04 (d, JHP 7.3 Hz);
FABMS (negative ion): m/z 505([M−H]−, 100%);
HRFABMS (negative ion): Calcd for C10H20O17P3
[M−H]−: 504.9913. Found: 504.9890.
(3%S,4%R) - 3% - (p - Methoxybenzyloxy)tetrahydrofuran-
4%-yl 3,4-di-O-acetyl-2,6-di-O-benzyl-h-
D-glucopyran-
(3%S,4%R) - 3% - Dibenzyloxyphosphoryloxytetrahydro-
furan-4%-yl 2,6-di-O-benzyl-3,4-bis-O-(dibenzyloxyphos-
oside (31).—A mixture of 30ab26 (1.81 g, 3.37 mmol),
,
(+)-22 (567 mg, 2.53 mmol) and 4 A molecular sieves
phoryl)-h-
D
-glucopyranoside (29).—A mixture of bis-
(1.50 g) in toluene (5 mL) and dioxane (15 mL) was
stirred for 2 h under an atmosphere of N2. ZnCl2 (506
mg) and AgClO4 (1.54 g) were added and the flask was
wrapped in foil. After stirring for a further 18 h TLC
(20:1 CH2Cl2–Me2CO) indicated the formation of one
major product (Rf 0.44). The foil was removed, toluene
(75 mL) was added, the resulting suspension was
filtered through Celite and the residue was well washed
with toluene. The filtrate and washings were transferred
to a separating funnel and washed with water, satd aq
NaHCO3 and satd aq NaCl (100 mL of each). The
organic layer was dried (MgSO4) and concentrated to
give a colourless residue. Purification by flash chro-
matography (eluent 30:1 CH2Cl2–Me2CO) gave the
title compound as a colourless glass (1.04 g, 1.60 mmol,
(benzyloxy)(diisopropylamino)phosphine (325 mg, 0.94
mmol) and 1H-tetrazole (99 mg, 1.41 mmol) in dry
CH2Cl2 (5 mL) was stirred at rt for 30 min whereupon
triol 28 (70 mg, 0.16 mmol) was added. The mixture
stirred for a further 30 min, then cooled to −78 °C,
and MCPBA (406 mg, 57%, 1.34 mmol) was added.
The cooling bath was removed and the mixture was
allowed to warm to rt. The reaction mixture was di-
luted with CH2Cl2 (50 mL) and was washed with 25 mL
each of 10% aq Na2SO3, satd aq NaHCO3 and satd aq
NaCl. The organic layer was dried (MgSO4), filtered
and concentrated to give an off-white solid. Flash
chromatography (eluent 3:2 EtOAc–hexane) gave the
title compound as a colourless oil (188 mg, 98%); [h]D
1
1
+30.0° (c 1.5, CHCl3); H NMR (CDCl3; 400 MHz) l
63%); [h]D+84.3° (c 1.3, CHCl3); H NMR (CDCl3;
7.35–7.03 (m, 40 H, Ph), 5.05–4.80 (m, 14 H, 5.5×
OCH2Ph, H-1, H-3, H-3%), 4.73 (AB, 1 H, JAB 11.9, JH,P
8.2 Hz, POCH2Ph), 4.63–4.50 (m, 3 H, H-4, OCH2Ph),
4.48, 4.36 (AB, 2 H, JAB 12.1 Hz, OCH2Ph), 4.08 (q, 1
H, J4%,3%:J4%,5%a:J4%,5%b:5.5 Hz, H-4%), 3.92 (dd, 1 H,
J5%a,5%b 9.2, H-5%a), 3.90–3.85 (m, 2 H, H-2%a, H-2%b),
3.82–3.77 (m, 2 H, H-5, H-5%b), 3.75–3.69 (m, 2 H,
H-6a, H-6b), 3.56 (dd, 1 H, J2,3 9.8, J2,1 3.7 Hz, H-2);
31P NMR (CDCl3; 161.7 MHz; 1H decoupled): l
−1.10, −1.94, −2.25, (3 s); FABMS (positive ion):
m/z 1227 ([M+1]+, 9%), 91 (100); HRFABMS (posi-
tive ion): Calcd for C66H70O17P3 [M+1]+: 1227.382.
Found: 1227.382.
400 MHz): l 7.34–7.15 (m, 12 H, Ar), 6.85–6.81 (m, 2
H, meta-H of PMB), 5.48 (t, 1 H, J3,2=J3,4=9.8 Hz,
H-3), 5.21 (d, 1 H, J1,2 3.4 Hz, H-1), 5.07 (t, 1 H, J4,5
9.8 Hz, H-4), 4.60–4.41 (m, 6 H, 3×AB systems of
OCH2Ar), 4.20 (q, 1 H, J:5.4 Hz, H-3% or H-4%), 4.06
(q, 1 H, J:5.9 Hz, H-3% or H-4%), 3.99–3.79 (m, 5 H,
H-5, H-2%a, H-2%b, H-5%a and H-5%b), 3.76 (s, 3 H,
ArOCH3), 3.58 (dd, 1 H, H-2), 3.50– 3.42 (m, 2 H,
H-6a and H-6b), 2.00 (s, 3 H, MeCO2), 1.89 (s, 3 H,
MeCO2); 13C NMR (CDCl3; 68 MHz): l 170.12, 169.73
(2×CꢁO), 159.27 (para-C of PMB), 137.87, 137.48
(ipso-C of Bn), 129.97 (ipso-C of PMB), 129.61, 128.31,
128.26, 127.88, 127.68, 127.55 (ArCH), 113.77 (meta-C

1080
A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
of PMB), 96.61 (C-1), 77.60, 76.34 (2×CH), 73.43,
72.35, 72.05 (OCH2Ar), 71.91 (CH), 70.45, 70.04 (C-2%
and C-5%), 69.04, 68.70 (2×CH), 67.76 (C-6), 55.19
(OCH3), 20.84, 20.63 (CH3CO2); FABMS (positive
ion): m/z 673 ([M+Na]+, 90%); 121 (100), 91 (65);
FABMS (negative ion): m/z 803 ([M+NBA]−, 100%);
Anal Calcd for C36H42O11: C, 66.45; H, 6.51. Found: C,
66.3; H, 6.60.
CH2Cl2–Me2CO) gave the title compound as a colour-
less oil (407 mg, 0.515 mmol, 82%); [h]D +89.7° (c 1,
CHCl3); H NMR (CDCl3; 270 MHz) l 7.31–7.22 (m,
1
20 H, Ph); 5.42 (t, 1 H, J 9.9 Hz, H-3), 5.10–5.00 (m,
6 H, 2 x OCH2Ph, H-1 and H-4), 4.91–4.83 (m, 1H,
H-3%), 4.63–4.41 (two overlapping ABq, 4 H, OCH2Ph),
4.21–4.13 (m, 1 H, H-4%), 4.00–3.79 (m, 5 H, H-5,
H-2%a H-2%b, H-5a% and H-5b%), 3.55 (dd, 1 H, J 10.1,
3.7 Hz, H-2), 3.52–3.41 (m, 2 H, H-6a and H-6b), 1.94
(s, 3 H, CH3CO2), 1.87 (s, 3 H, CH3CO2); 31P NMR
(CDCl3; 162 MHz, proton coupled) l –1.34 (apparent
(3%S,4%R)-3%-Hydroxytetrahydrofuran-4%-yl 3,4-di-O-
acetyl-2,6-di-O-benzyl-h-
D
-glucopyranoside
(32).—
Trifluoroacetic acid (2 mL) was added to a solution of
31 (750 mg, 1.15 mmol) in CH2Cl2 (18 mL). The
resulting purple solution was stirred at rt for 30 min,
and then poured slowly, with vigorous stirring, into
satd aq NaHCO3 (50 mL). The organic layer was
removed, dried (MgSO4), and concentrated to give an
oil. Purification by flash chromatography (eluent 10:1
CH2Cl2–Me2CO) gave the title compound as a colour-
less oil (493 mg, 0.929 mmol, 81%) which crystallised
after one week at rt; mp 64–65 °C (diisopropyl ether);
[h]D+104° (c 0.8, CHCl3); 1H NMR (CDCl3; 400
MHz): l 7.38–7.26 (m, 10 H, ArH); 5.44 (t, 1 H,
3
sextet, 1P, JHPꢀ8 Hz); FABMS (positive ion): m/z
813.4 ([M+Na]+, 50%), 791.4 ([M+H]+, 80%), 91
(100); FABMS (negative ion): m/z 943.3 ([M+NBA]−,
90%], 699.2 ([M−C7H7]−, 90%], 277.1 (40); Anal
Calcd for C42H47O13P: C, 63.79; H, 5.99. Found: C
63.9; H 6.00.
(3%S,4%R) - 3% - Dibenzyloxyphosphoryloxytetrahydro-
furan-4%-yl 2,6-di-O-benzyl-h- -glucopyranoside (34).—
D
A solution of 33 (360 mg, 0.455 mmol) in NH3-satu-
rated anhyd MeOH (20 mL) was stirred at rt in a sealed
Pyrex autoclavable bottle for 18 h. TLC (EtOAc) indi-
cated complete consumption of starting material (Rf
0.48) and the appearance of a more polar product (Rf
0.30). The solution was concentrated and the residue
was purified by flash chromatography (eluent EtOAc–
hexane 5:1) to give diol 34 as a colourless oil (204 mg,
0.289 mmol, 64%); [h]D +71.8° (c 0.7, CHCl3); 1H
NMR (CDCl3; 270 MHz) l 7.36–7.25 (m, 20 H, Ph),
5.11–4.95 (m, 5 H, H-1 and 2×OCH2Ph), 4.91–4.84
(m, 1 H, JHP 7.1 Hz, H-3%), 4.60, 4.55 (ABq, 2 H, JAB
12.3 Hz, OCH2Ph), 4.69, 4.51 (ABq, 2 H, JAB 11.9 Hz,
OCH2Ph), 4.00–3.73 (m, 5 H, H-3, H-2%a, H-2%b, H-5%a,
H-5%b), 3.70–3.62 (m, 3 H, H-5, H-6a, H-6b), 3.59–3.50
(m, 1 H, H-4), 3.33 (dd, 1 H, J2,3 9.7, J2,1 3.7 Hz, H-2),
2.97 (br s, 1 H, OH), 2.82 (br s, 1 H, OH); 31P NMR
(CDCl3; 109 MHz, proton coupled) l −0.37 (apparent
J3,4=J3,2=9.9 Hz, H-3), 5.08 (t, 1 H, J4,5 9.9 Hz, H-4),
4.90 (d, 1 H, J1,2 3.7 Hz, H-1), 4.68, 4.61 (AB, 2 H, JAB
11.9 Hz, OCH2Ph), 4.58, 4.43 (AB, 2 H, JAB 12.2 Hz,
OCH2Ph), 4.26 (q, 1 H, J:5.5 Hz, H-3% or H-4%), 4.16
(q, 1 H, J:5.5 Hz, H-3% or H-4%), 4.01–3.91 [m, 3 H,
H-2, H-5 and (H-2%a or H-5%a)], 3.81 (dd, 1 H, J 9.8, 4.3
Hz, H-2%b or H-5%b), 3.67–3.63 [m, 2 H, (H-2%a and
H-2%b) or (H-5%a and H-5%b)], 3.48 (ABX, 2 H, J6a,6b
10.8, J6a,5 2.7, J6b,5 3.7 Hz, H-6a and H-6b), 1.93 (s, 3
H, CH3CO2), 1.89 (s, 3 H, CH3CO2); 13C NMR
(CDCl3; 100 MHz): l 170.16, 169.67 (CꢁO), 137.33,
136.77 (ipso-C of Bn), 128.61, 128.35, 128.32, 128.19,
127.90, 127.75 (Ph), 98.23 (C-1), 78.79, 76.29 (2×CH),
74.11, 73.42, 72.45 (3×CH2), 72.39, 70.82 (2×CH),
70.81 (CH2), 69.05, 68.75 (2×CH), 67.49 (C-6), 20.80,
20.55 (CH3CO2); FABMS (positive ion): m/z 553
([M+Na]+, 20%), 181 (30), 91 (100); FABMS (nega-
tive ion): m/z 683 ([M+NBA]−, 100%]; Anal Calcd for
C28H34O10: C, 63.39; H, 6.46. Found: C 63.1; H 6.49.
(3%S,4%R) - 3% - Dibenzyloxyphosphoryloxytetrahydro-
3
sextet, 1 P, JHꢀ7 Hz); FABMS (positive ion): m/z
729.3 ([M+Na]+, 30%), 707.3 ([M+H]+, 90%), 91
(100);%); HRFABMS (positive ion): Calcd for
[C38H43O11P+H+]+ 707.2621. Found: 707.2622.
(3%S,4%R) - 3% - Dibenzyloxyphosphoryloxytetrahydro-
furan-4%-yl 2,6-di-O-benzyl-3,4-bis-O-(dibenzyloxythio-
furan-4%-yl 3,4-di-O-acetyl-2,6-di-O-benzyl-h-D-gluco-
pyranoside (33).—To a solution of the alcohol (335 mg,
0.631 mmol) in dry CH2Cl2 (3 mL) was added 1H-tet-
razole (88 mg, 1.3 mmol) followed by bis(benzy-
loxy)(diisopropylamino)phosphine (327 mg, 0.947
mmol). The mixture was stirred under N2 at rt for 1 h
and then cooled to −78 °C. MCPBA (380 mg, 57%,
1.26 mmol) was added, the cooling bath was removed,
and the mixture was allowed to warm to rt. The
mixture was diluted with CH2Cl2 (50 mL) and was
washed with 50 mL each of 10% w/v aq Na2SO3, satd
aq NaHCO3 and satd aq NaCl. The organic layer was
dried (MgSO4) and concentrated. Purification of the
residue by flash chromatography (eluent 15:1 then 10:1
phosphoryl)-h-D-glucopyranoside (35).—To a solution
of diol 34 (122 mg, 0.173 mmol) in dry CH2Cl2 (2 mL)
was added 1H-tetrazole (48 mg, 0.69 mmol) followed
by bis(benzyloxy)(diisopropylamino)phosphine (179
mg, 0.519 mmol). The mixture was stirred under N2 at
rt for 1 h and then concentrated by evaporation under
reduced pressure (no heat). The residue was taken up in
dry DMF (2 mL), and dry pyridine (1 mL) was added
followed by sulphur (22 mg, 0.69 mmol). The mixture
was stirred under N2 at rt for 1 h and then concentrated
by evaporation in vacuo. The residue was taken up in
CH2Cl2 (30 mL) and the solution was washed with
brine (30 mL), dried (MgSO4) and concentrated to give

A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
1081
a yellow oil. Purification by flash chromatography (elu-
ent 1:1 EtOAc–hexane) gave the title compound as a
colourless oil (182 mg, 0.145 mmol, 84%); [h]D +28.3°
H-3), 4.44 (q, J4%,3%:J4%,5%a:J4%,5%b 5 Hz, H-4%), 4.20 (dt,
1 H, J4,P 11.3, J4,5 9.0 Hz, H-4), 4.06–3.67 (m, 8 H,
H-2, H-5, H-6a, H-6b, H-2%a, H-2%b, H-5%a and H-5%b);
31P NMR (D2O; 109 MHz, Et3N added) l 51.42 and
50.01 (P-3 and P-4), 0.675 (P-3%); FABMS (negative
ion): m/z 537([M−H]−, 100%); HRFABMS (negative
ion): Calcd for C10H20O15P3S2 [M−H]− 536.9457,
Found: 536.9457.
1
(c 1.4, CHCl3); H NMR (CDCl3; 270 MHz) l 7.36–
7.12 (m, 38 H, Ph), 7.05–7.01 (m, 2 H, Ph), 5.26–4.80
(m, 15 H, 5.5×OCH2Ph, H-1, H-3, H-4, and H-3%),
4.62 (dd, 1 H, JAB 11.9, JH,P 10.9 Hz, 0.5 POCH2Ph),
4.50 (br s, 2 H, OCH2Ph), 4.37, 4.26 (AB, 2 H, JAB 11.9
Hz, OCH2Ph), 4.00–3.85 (m, 5 H, H-5, H-2%a, H-2%b,
H-4% and H-5%a), 3.79 (dd, 1 H, J 7.9, 5.9 Hz, H-5%b),
3.65–3.70 (m, 2 H, H-6a, H-6b), 3.61 (dd, 1 H, J2,3 9.2,
Acknowledgements
1
J2,1 3.6 Hz, H-2); 31P NMR (CDCl3; 109 MHz; H-de-
coupled): l 69.09 and 68.38 (P-3 and P-4), −0.49
(P-3%); FABMS (positive ion): m/z 1259.3 ([M+1]+,
40%), 271(50), 91 (100); FABMS (negative ion): m/z
1167.3 ([M−C7H7]−, 50%), 293.1 ([(BnO)2P(S)O2]−,
100%); Anal Calcd for C66H69O15P3S2: C, 62.95; H,
5.52. Found: C 62.8; H 5.56.
We thank the Wellcome Trust for a Prize Stu-
dentship (to R.D.M.) and for Programme Grant sup-
port (060554 to B.V.L.P.).
References
(3%S,4%R)-3%-Hydroxytetrahydrofuran-4%-yl h-D-gluco-
pyranoside 3%-phosphate 3,4-bisphosphorothioate (6).—
Ammonia (100 mL) was condensed into a 250 mL
three-neck flask at −78 °C. Excess sodium metal was
added in small pieces, with stirring, until the liquid
remained a deep blue–black colour. The cooling bath
was removed, and 30 mL of NH3 was then allowed to
distil from the first flask into a 100-mL three-neck flask
kept at −78 C under N2. To this pure dry liquid NH3
was now added freshly-cut sodium metal (two slivers,
each approx 5×5×2 mm). After 10 min of stirring at
−78 °C (the blue–black colour should be retained) a
solution of 35 (94 mg, 75 mmol) in anhyd dioxane (2
mL) was added. The mixture was stirred at −78 °C for
60–90 s and then quenched by addition of EtOH in
small portions (CARE!) until all the colour had disap-
peared. De-ionised water (30 mL) was added, and the
cooling bath was removed. Most of the NH3 was
allowed to evaporate off under a stream of N2, and the
remaining liquid was then carefully transferred to a
500-mL round-bottom flask. The solvents and remain-
ing NH3 were then removed by evaporation under
reduced pressure (no heat). The residue was taken up in
de-ionised water (500 mL) and loaded onto a column of
Q Sepharose Fast Flow resin. The column was eluted
with a gradient of triethylammonium bicarbonate
buffer (0–1 M, pH 7.5). The triethylammonium salt of
6 eluted over 850–900 mM buffer. Fractions containing
6 were combined and concentrated by evaporation un-
der reduced pressure (no heat). Methanol was added to
the residue and repeatedly evaporated to destroy re-
maining triethylammonium bicarbonate. Eventually,
the pure triethylammonium salt of 6 remained as a
glassy residue (53 mg, 57 mmol, subsequently quantified
by Ames total phosphate assay,38 76%); [h]D +38.7° (c
1. Mikoshiba K. Curr. Opin. Neurobiol. 1997, 7, 339–345.
2. Potter B. V. L.; Lampe D. Angew. Chem. Int. Ed. Engl.
1995, 34, 1933–1972.
3. Takahashi M.; Kagasaki T.; Hosoya T; Takahashi S. J.
Antibiot. 1993, 46, 1643–1647.
4. Takahashi S.; Kinoshita T.; Takahashi M. J. Antibiot.
1994, 47, 95–100.
5. Takahashi M.; Tanzawa K.; Takahashi S. J. Biol. Chem.
1994, 269, 369–372.
6. Hotoda H.; Takahashi M.; Tanzawa K.; Takahashi S.;
Kaneko M. Tetrahedron Lett. 1995, 36, 5037–5040.
7. van Straten N. C. R.; van der Marel G. A.; van Boom J.
H. Tetrahedron 1997, 53, 6509–6522.
8. Marwood R. D.; Riley A. M.; Jenkins D. J.; Potter B. V.
L. J. Chem. Soc., Perkin Trans. 1 2000, 1935–1947.
9. Wilcox R. A.; Erneux C.; Primrose W. U.; Gigg R.;
Nahorski S. R. Mol. Pharmacol. 1995, 47, 1204–1211.
10. Jenkins D. J.; Potter B. V. L. Carbohydr. Res. 1996, 287,
169–182.
11. Marchant J. S.; Beecroft M. D.; Riley A. M.; Jenkins D.
J.; Marwood R. D.; Taylor C. W.; Potter B. V. L.
Biochemistry 1997, 36, 12780–12790.
12. Jenkins D. J.; Marwood R. D.; Potter B. V. L. Chem.
Commun. 1997, 449–450 Corrigendum 805.
13. Marwood R. D.; Riley A. M.; Correa V.; Taylor C. W.;
Potter B. V. L. Bioorg. Med. Chem. Lett. 1999, 9, 453–
458.
14. Shuto S.; Tatani K.; Ueno Y.; Matsuda A. J. Org. Chem.
1998, 63, 8815–8824.
15. Correa V.; Riley A. M.; Shuto S.; Horne G.; Nerou E. P.;
Marwood R. D.; Potter B. V. L.; Taylor C. W. Mol.
Pharmacol. 2001, 59, 1206–1215.
16. Barker R.; Fletcher H. G., Jr. J. Org. Chem. 1961, 26,
4605–4609.
17. Johansson R.; Samuelsson B. J. Chem. Soc., Perkin
Trans. 1 1984, 2371–2374.
18. Prystasˇ M.; Sorm F. Collect. Czech. Chem. Commun.
1971, 36, 1472–1481.
19. Joniak D.; Kosˇ´ıkova´ B.; Kosa´kova´ L. Collect. Czech.
Chem. Commun. 1978, 43, 769–773.
20. Evans D. A.; Kaldor S. W.; Jones T. K.; Clardy J.; Stout
T. J. J. Am. Chem. Soc. 1990, 112, 7001–7031.
21. Lee J.; Marquez V. E.; Lewin N. E.; Blumberg P. M.
Bioorg. Med. Chem. Lett. 1994, 4, 543–548.
1
1.0, MeOH); H NMR (D2O; 270 MHz) l 5.21 (d, 1 H,
J1,2 3.7 Hz, H-1); 4.80–4.71 (m, 1 H, partially buried by
HDO signal, H-3%), 4.64 (q, 1 H, J3,2:J3,4:J3,P 10 Hz,

1082
A.M. Riley et al. / Carbohydrate Research 337 (2002) 1067–1082
31. Safrany S. T.; Wilcox R. A.; Dubreuil D.; Potter B. V. L.;
Nahorski S. R. Mol. Pharmacol. 1993, 43, 499–503.
32. Murphy C. T.; Riley A. M.; Mills S. J.; Lindley C. J.; Potter
B. V. L.; Westwick J. Mol. Pharmacol. 2000, 57, 595–601.
33. Wilcox R. A.; Fauq A.; Kozikowski A. P.; Nahorski S. R.
FEBS Lett. 1997, 402, 241–245.
34. Douglas N. L.; Ley S. V.; Lu¨cking U.; Warriner S. L. J.
Chem. Soc., Perkin Trans. 1 1998, 51–65.
35. Mills S. J.; Riley A. M.; Murphy C. T.; Bullock A. J.;
Westwick J.; Potter B. V. L. Bioorg. Med. Chem. Lett. 1995,
5, 203–208.
36. Mak D.-O. D.; McBride S.; Foskett J. K. J. Gen. Physiol.
2001, 117, 299–314.
37. Parekh A. B.; Riley A. M.; Potter B. V. L. Biochem. J. 2002,
361, 133–141.
38. Ames B. N.; Dubin D. T. J. Biol. Chem. 1960, 235,
769–775.
39. Lampe D.; Liu C.; Potter B. V. L. J. Med. Chem. 1994,
37, 907–912.
22. Sviridov A. F.; Ermolenko M. S.; Yashunsky D. V.;
Borodkin V. S.; Kochetkov N. K. Tetrahedron Lett. 1987,
28, 3835–3838.
23. Desai T.; Gigg J.; Gigg R. Carbohydr. Res. 1996, 280,
209–221.
24. Schmidt R. R.; Michel J.; Roos M. Liebigs Ann. Chem.
1984, 1343–1357.
25. Marwood R. D.; Shuto S.; Jenkins D. J.; Potter B. V. L.
Chem. Commun. 2000, 219–220.
26. Marwood R. D.; Jenkins D. J.; Correa V.; Taylor C. W.;
Potter B. V. L. J. Med. Chem. 2000, 43, 4278–4287.
27. Shuto S.; Horne G.; Marwood R. D.; Potter B. V. L. Chem.
Eur. J. 2001, 7, 4937–4946.
28. Altenbach H.-J.; Wolf E. Tetrahedron: Asymmetry 1993, 4,
2155–2158.
29. Watanabe Y.; Nakamoto C.; Yamamoto T.; Ozaki S.
Tetrahedron 1994, 50, 6523–6536.
30. Yan L.; Kahne D. Synlett 1995, 523–524.