Sialyltransferase inhibitors based on CMP-quinic acid

Article abstract of DOI:10.1002/(SICI)1099-0690(200005)2000:9<1745::AID-EJOC1745>3.0.CO;2-8

Quinic acid was transformed into phosphitamides 16, 25, and 36, which could be readily linked to 5'-O-unprotected cytidine derivative 17. Ensuing oxidation of the obtained phosphite triesters with tBuO₂H and hydrogenolytic de-O-benzylation furnished the corresponding phosphate diesters 18, 26, and 38. Base catalyzed removal of acetyl protecting groups, and methyl ester hydrolysis furnished CMP-Neu5Ac analogues 1d, 1e, and 2. Quinic acid was also transformed into 1,2-unsaturated diallyl α-hydroxymethyl-phosphate derivatives (R)- and (S)-46, which on reaction with cytidine phosphitamide 47 afforded the phosphite triesters. Subsequent oxidation with tBuO₂H and then treatment with NEt₃ gave phosphate diester derivatives (R)- and (S)-48. Deallylation, acetyl group removal, and methyl ester hydrolysis furnished (R)- and (S)-3, respectively. Treatment of (R)- and (S)-48 with DBU as a base led to acetic acid elimination, thus yielding, after de-O-allylation, acetyl group cleavage, and ester hydrolysis, diene derivative (E)-4. Donor substrate analogues 1d and 1e exhibited good α(2-6)-sialyltransferase inhibition (K(i): 2.0 · 10^-4 and 2.0 · 10^-5 M). However, transition state analogues (R)-, and particularly (S)-3 showed excellent inhibition properties (K(i): 1.6 · 10^-6 and 2.7 · 10^-7 M).

Full text of DOI:10.1002/(SICI)1099-0690(200005)2000:9<1745::AID-EJOC1745>3.0.CO;2-8

FULL PAPER
Sialyltransferase Inhibitors Based on CMP-Quinic Acid
Christoph Schaub,[a] Bernd Müller,[a] and Richard R. Schmidt*[a]
Keywords: CMP-Neu5Ac analogues / Enzyme inhibitors / Substrate analogues / Transition state analogues / (2–6)-
Sialyltransferase / Carbohydrates
Quinic acid was transformed into phosphitamides 16, 25, and
36, which could be readily linked to 5Ј-O-unprotected cytid-
idation with tBuO2H and then treatment with NEt3 gave
phosphate diester derivatives (R)- and (S)-48. Deallylation,
ine derivative 17. Ensuing oxidation of the obtained phos- acetyl group removal, and methyl ester hydrolysis furnished
phite triesters with tBuO2H and hydrogenolytic de-O-benzyl- (R)- and (S)-3, respectively. Treatment of (R)- and (S)-48 with
ation furnished the corresponding phosphate diesters 18, 26,
and 38. Base catalyzed removal of acetyl protecting groups,
DBU as a base led to acetic acid elimination, thus yielding,
after de-O-allylation, acetyl group cleavage, and ester hydro-
and methyl ester hydrolysis furnished CMP-Neu5Ac ana- lysis, diene derivative (E)-4. Donor substrate analogues 1d
logues 1d, 1e, and 2. Quinic acid was also transformed into and 1e exhibited good α(2–6)-sialyltransferase inhibition (Ki:
1,2-unsaturated diallyl α-hydroxymethyl-phosphate derivat- 2.0 10–4 and 2.0 10–5
). However, transition state analogues
M
ives (R)- and (S)-46, which on reaction with cytidine phosphi-
(R)-, and particularly (S)-3 showed excellent inhibition prop-
tamide 47 afforded the phosphite triesters. Subsequent ox- erties (Ki: 1.6 10–6 and 2.7 10–7
M).
Introduction
Sialic acid containing glycoconjugate epitopes are in-
volved in various biological interactions, such as the many
forms of cell adhesion, thus influencing a variety of physio-
logically and pathologically important processes.[1] Re-
cently, an interesting correlation between α(2–6)-sialylation
of N-acetyllactosamine and B lymphocyte activation an im-
mune function was reported, which could find medicinal
application.[2] Therefore, in order to study the influence of
sialyl residues in biological systems, it is highly desirable to
develop efficient inhibitors for sialyltransferases.
The various sialyltransferases employ, independent of
their source and their acceptor specificity, cytidine mono-
phosphate N-acetylneuraminic acid (CMP-Neu5Ac,
Scheme 1) as the donor substrate. As was recently shown by
us,[3–6] structural analogues of the donor and particularly of
the transition state CMP-Neu5Ac϶ of the donor
(Scheme 1) exhibit high affinity to sialyltransferases; there-
fore, they are valuable inhibitors.[3–7] We present here new
sialyltransferase inhibitors, which are based on quinic acid
transformations; also their inhibition properties towards
α(2–6)-sialyltransferase from rat liver (EC 2.4.99.1) will be
communicated.[8]
An efficient inhibitor requires high binding affinity to the
Scheme 1. Mechanism of the sialylation
active site (generally provided by substrate and/or transition
state analogues with competitive binding) and high stability
under physiological conditions. Following previous reports,
binding of donor analogues to sialyltransferases requires
the CMP moiety or at least a nucleoside monophosphate
residue,[9] yet structural variations in the phosphate group
and the 4-, 5-, or 9-position of the Neu5Ac residue[10–12]
are tolerated. Additionally, in order to block the transferase
potential of the enzymes, stability of the glycosidic bond is
required. All these demands can be almost ideally fulfilled
by quinic acid and derivatives having the CMP moiety at-
tached to the tertiary hydroxy group. Therefore, we initiated
a programme for the synthesis of this type of com-
pound[8,13] – typical examples are compounds of type 1–
4 (Scheme 2). The synthesis of compounds 1a–c has been
previously reported.[3] Compounds 1d and 1e are donor
[a]
Fakultät Chemie, Universität Konstanz, Fach M 725,
D-78457 Konstanz, Germany
Eur. J. Org. Chem. 2000, 1745Ϫ1758
WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
1434Ϫ193X/00/0509Ϫ1745 $ 17.50ϩ.50/0
1745

C. Schaub, B. Müller, R. R. Schmidt
FULL PAPER
acid furnished a 2:5 mixture of 9 and desired azide 10. Az-
ide group reduction in 10 with hydrogen and Pd/C as the
catalyst and then treatment with trifluoracetic anhydride
[(TFA)2O] in the presence of NaHCO3 gave trifluoroacetyl-
amino derivative 11.
For the introduction of the equatorial acetylamino group
in 4-position, first inversion of configuration of the 4-hy-
droxy group in 11 was performed; to this end, the triflate
was generated by treatment of 11 with trifluoromethanesul-
fonic anhydride (Tf2O) in pyridine and then reaction with
tetrabutylammonium nitrile[17] was carried out to afford the
desired compound 12. Activation of the 4-hydroxy group
by triflate formation and then reaction with lithium azide
in DMF at 60 °C led to azide 13. Reduction of the azido
group as described above and acetylation with acetic anhyd-
ride in pyridine furnished 14, which possesses the equatorial
4-acetylamino group. De-O-acetylation of 14 under
[18]
´
Zemplen conditions,
and then selective 5-O-acetylation
with acetic anhydride in pyridine afforded 15, which gave,
on treatment with benzyloxy-chloro-diisopropylaminopho-
sphane[19] in the presence of Hünig base, phosphitamide di-
ester 16.
The structural assignment of 13–16 can be derived from
1
the H-NMR data; for instance, 15: J3,4 ϭ J4,5 ϭ 10.6 Hz.
Condensation of 16 with known 5Ј-O-unprotected cytidine
derivative 17[3,8] in the presence of tetrazole as catalyst, then
immediate oxidation of the phosphite triester with tert-bu-
tyl hydroperoxide and finally hydrogenolytic de-O-benzyl-
ation with Pd/C as catalyst afforded protected target molec-
ule 18 in 32% overall yield from 16. Deacetylation was car-
[18]
´
ried out under Zemplen conditions,
which led to the
formation of some lactam as by-product (by reaction of the
ester moiety with the 3-amino group), thus supporting the
structural assignments; for ester hydrolysis of the main
product lithium hydroxide was employed. Preparative
HPLC with triethylammonium bicarbonate as buffer and
then ion exchange with Liϩ afforded pure 1d as the dili-
thium salt in 67% yield.
Scheme 2. Target molecules
Synthesis of CMP-quinic acid derivative 1e, with a side
chain mimic relating it more closely to CMP-Neu5Ac,
started also from compound 5. Selective 5-O-allylation was
carried out with allyl trichloroacetimidate[20] in the presence
of TfOH as catalyst, providing desired 19 in 90% yield
(Scheme 4). 1-O-Acetylation of 19 to give 20 with acetic
anhydride in pyridine required addition of Steglich base [4-
(dimethylamino)pyridine, DMAP]. Ozonolysis of the allyl
group in 20 and then treatment of the product with sodium
substrate analogues having an amino group in 3ЈЈ-position
or, alternatively, a side chain mimic in 5ЈЈ-position. Com-
pounds 2, and particularly 3 and 4, are – as recently discus-
sed[5,6] – transition state analogues of CMP-Neu5Ac.
Results and Discussion
Synthesis of Donor Analogues 1d and 1e
For the synthesis of CMP-quinic acid derivative 1d, borohydride afforded 5-hydroxyethyl derivative 21. Reac-
quinic acid was transformed into known 3,4-O-cyclohexyli- tion with acetic anhydride in pyridine furnished 22, which
dene derivative 5[14] (Scheme 3). Ensuing O-acetylation with on treatment with aqueous acetic acid led to de-O-cyclohex-
acetic anhydride in pyridine (Ǟ 6), then de-O-cyclohexylid- ylidenated compound 23. Cleavage of all O-acyl groups un-
[18]
´
enation with ethylmercaptan in the presence of p-tolu- der Zemplen conditions and then selective O-acetylation
enesulfonic acid (pTsOH) as catalyst[15] (Ǟ 7), and finally with acetic anhydride in pyridine gave 1-O-unprotected
reaction with thionyl chloride in the presence of triethylam- quinic acid derivative 24. The same procedure as described
[16]
ine as base and oxidation with RuCl3/NaIO4
afforded for 16, i.e. phosphitylation to give 25 and then reaction with
cyclic sulfate 8 in high overall yield. Nucleophilic substitu- 17 in the presence of tetrazole, subsequent oxidation with
tion of 8 with lithium azide in DMF as solvent, and then tert-butyl hydroperoxide, and hydrogenolytic debenzylation,
hydrolysis of the attached sulfate group in aqueous sulfuric gave protected target molecule 26 in 62% yield. Removal of
1746
Eur. J. Org. Chem. 2000, 1745Ϫ1758

Sialyltransferase Inhibitors Based on CMP-Quinic Acid
FULL PAPER
Scheme 3. Synthesis of 1d. Reagents and conditions: (a) AcO, Pyr. – (b) EtSH, pTsOH, CH2Cl2. – (c) SOCl2, NEt3; RuCl3, NalO4,
MeCN/EtOAc/H2O (68%). – (d) LiN3, DMF; H2SO4, H2O/THF (88%, 10/9 ϭ 5:2). – (e) Pd/H2; (TFA)2O, NaHCO3 (66%). – (f) Tf2O,
Pyr; Bu4NϩNO2 (55%). – (g) Tf2O, Pyr; LiN3, DMF (75%). – (h) Pd/C, H2; Ac2O, Pyr (72%). – (i) NaOMe, MeOH; Ac2O, Pyr (81%). –
–
(j) ClP(OBn)NiPr2EtNiPr2 (91%). – (k) Tetrazole, MeCN; tBuO2H; Pd/C, H2, MeOH; NEt3(32%). – (l) NaOMe, MeOH; LiOH (67%).
´
the O- and N-acyl protective groups under Zemplen condi- tam 34 as by-product, thus supporting the structural assign-
tions[18] and then methyl ester saponification with sodium ments (yield: 93%; 33/34 ϭ 3:2). Immediate treatment of 33
hydroxide afforded target molecule 1e as the disodium salt with acetic anhydride in pyridine and catalytic amounts of
in 50% yield.
DMAP afforded 1-O-unprotected derivative 35. The same
procedure as described for 16, namely phosphitylation to
give 36 and then reaction with 17 in the presence of tetra-
zole, followed by oxidation with tert-butyl hydroperoxide to
give phosphate 37 and then hydrogenolytic debenzylation
afforded protected target molecule 38. Removal of the O-
Synthesis of Transition State Analogues 2–4
The introduction of a 2,3-CϭC double bond into quinic
acid in order to arrive at target molecule 2 could be readily
accomplished with cyclic sulfate 8 (Scheme 5): treatment of
8 with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in THF at
80 °C led to 2,3-elimination; the generated 4-O-hydrogen
sulfate group could be readily removed under aqueous acid
conditions providing 27 in 88% yield. Oxidation of the lib-
erated 4-hydroxy group with periodinane[21] afforded ketone
and N-acetyl groups under Zemplen conditions[18] and then
´
methyl ester hydrolysis with sodium hydroxide in aqueous
methanol furnished target molecule 2 as disodium salt in
69% yield.
Quinic acid transformation into 39 (Scheme 6) having an
28, which was transformed into oxime 29. Ensuing reduc- α,β-unsaturated ketone moiety and reduction of the keto
tion of 29 with zinc in acetic acid/acetic anhydride afforded group to afford compound 40 has been already performed
the desired 4-acetylamino derivative 30, though in only 24% by Shing and Tang.[14] Mitsunobu reaction[22] of 40 with
yield. Therefore, compound 27 was transformed into mesyl- benzoic acid as a nucleophile, furnished 41 with a pseudo-
ate 31 by treatment with methanesulfonyl chloride in pyrid- axial 3-benzoyloxy group. De-O-cyclohexylidenation with
ine; immediate reaction with lithium azide in DMF at 70 aqueous acetic acid led to 42, which on de-O-acylation un-
°C furnished azido derivative 32. Dithiothreitol (DTT) re- der Zemplen conditions,[18] ester hydrolysis with sodium hy-
´
duction in aqueous pyridine in the presence of triethylamine droxide, and then acetylation with acetic anhydride, fur-
and then treatment with acetic anhydride in pyridine af- nished acid 43. Formation of a mixed anhydride by treat-
forded 30 in very good overall yield.
ment with ethyl chloroformate in the presence of N-methyl-
The structural assignment of 30 and 32 can be derived piperidine (NMP) as base, and then reaction with N,O-
1
from the H-NMR data; 32: J2,3 ϭ 9.9, J3,4 ϭ 5.5, J4,5
ϭ
dimethyl-hydroxylamine afforded Weinreb[23] amide 44,
´
4.1 Hz. On de-O-acetylation of 30 under Zemplen condi- which gave the formyl derivative 45, on careful monitoring
tions,[18] we not only obtained the desired 33, but also lac- of the reduction with sodium dihydro-bis(2-methoxyethoxy)-
Eur. J. Org. Chem. 2000, 1745Ϫ1758
1747

C. Schaub, B. Müller, R. R. Schmidt
FULL PAPER
Scheme 4. Synthesis of 1e. Reagents and conditions: (a) All–O–C(ϭ
NH)CCl3, TFOH (90%). – (b) Ac2O, Pyr, DMAP (82%). – (c)
Ozone, MeOH/CH2Cl2, –78 °C; NaBH4, –78 °CǞ room temp.
(73%). – (d) Ac2O, Pyr (92%). – (e) HOAc/H2O (qu). – (f) NaOMe,
MeOH; Ac2O, Pyr (70%). – (g) ClP(OBn)NiPr2, EtNiPr2 (65%. –
(h) Tetrazole, MeCN; tBuO2H; Pd/C, H2, MeOH; NEt3 (62%). –
(i) NaOMe, MeOH; NaOH, MeOH/H2O (59%).
Scheme 5. Synthesis of 2. Reagents and conditions: (a) DBU, THF,
70 °C; H2SO4/H2O (88%). – (b) Periodinane (83%). – (c) H2N–OH
(qu). – (d) Ac2O/HOAc, Zn (24%). – (e) MsCl, Pyr. – (f) LiN3,
DMF, 70 °C (84%, two steps). – (g) DTT, Pyr/H2O; Ac2O, Pyr
(87%). – (h) NaOMe, MeOH (33: 59%, 34: 34%). – (i) Ac2O, Pyr,
DMAP (62%). – (j) ClP(OBn)NiPr2, EtNiPr2, MeCN. – (k) Tetra-
zole, MeCN; tBuO2H; NEt3 (31%, 2 steps). – (l) Pd/C, H2, MeOH;
NEt3 (84%). – (m) NaOMe, MeOH; NaOH, MeOH (69%).
aluminate (RedAl) in toluene/THF at –60 °C. Reaction of
45 with diallyl hydrogen phosphonate[24] in the presence of
triethylamine as a base, afforded a 1:1-mixture of diallyl
phosphonates (R)- and (S)-46 in 92% yield, which could be
separated by MPLC chromatography. (R)- and (S)-46 were
treated with known cytidine-phosphite derivative 47[25] in
the presence of tetrazole; subsequent oxidation of the reac-
tion product with tert-butyl hydroperoxide and then addi-
tion of triethylamine in order to remove the cyanoethyl
group led to protected target molecules (R)-48 and (S)-48,
respectively, in high yields. De-O-allylation with catalytic
Pd(PPh3)4 and dimedone as the nucleophile,[26] ensuing de-
acylation with aqueous ammonia, and then ion exchange
gave target molecules (R)-3 and (S)-3 as the trisodium salts
in high yields.
Treatment of (R)-48 and (S)-48, or a mixture of the two,
with DBU at 70 °C led to acetic acid elimination. Finally,
reaction with acetic anhydride in pyridine in order to ensure
complete O-acylation, then de-O-allylation, deacylation,
and ion exchange as described above, led exclusively to the
(E)-isomer of diene 4 in 34% yield; (E)-4 was isolated as the
trisodium salt.
(S)-46, the Dale–Mosher method[27] was employed
(Scheme 7). To this end, (R)- and (S)-46 were treated with
the (R)-isomer of α-methoxy-α-(trifluoromethyl)phenylace-
tyl chloride[24] (MTPA-Cl) (R)-49 which gave in the pres-
ence of pyridine the two diastereoisomers (R,S)- and (S,S)-
50. Based on the generally accepted model for Mosher es-
ters[28,29] (Scheme 7), the downfield shift of the methoxy
1
group in the H NMR (∆δ ϭ 0.15 ppm) is associated with
the (R,S)-isomer and also the downfield shift of the phos-
phorous atom in the 31P NMR (∆δ ϭ 0.48 ppm). The con-
figurational assignment of 4 is based on 31P-13C coupling
observed in the 13C NMR: Coupling with C-2ЈЈ is 11 Hz
and coupling with C-6ЈЈ is ca. 0 Hz, thus (E)-configuration
for 4 is derived.
Determination of the Ki Values of 1–4
The structural assignments were essentially based on the
Measurement of the Ki values of compounds 1–4 is based
NMR data. For the configurational assignment of (R)- and on a previously reported sialyltransferase assay system.[3]
1748
Eur. J. Org. Chem. 2000, 1745Ϫ1758

Sialyltransferase Inhibitors Based on CMP-Quinic Acid
FULL PAPER
As can be seen in Table 1, the previously obtained donor
substrate analogues 1a and b[3] exhibit comparable affinity
to α(2–6)-sialyltransferase from rat liver (E.C. 2.4.99.1) as
the natural substrate CMP-Neu5Ac. However, introduction
of an equatorial amino group into the 3ЈЈ-position as in
1c, unexpectedly, reduced binding by almost two orders of
magnitude. This dramatic effect could be only partly com-
pensated by replacing the equatorial hydroxy group in 1c
by an acetylamino group as in 1d. However, attachment of
a simple hydroxyethyl group at the 5ЈЈ-oxygen of the quinic
acid moiety as in 1e led to greatly improved binding which
even surpasses the natural substrate. Yet, none of these
compounds exhibited strong inhibition. This was immedi-
ately changed when a double bond was introduced in the
quinic acid moiety, thus mimicking the potential transition
state of the enzymatic sialyl transfer.[5,6] Compound 2 al-
ready exhibited a threefold higher binding to α(2–6)-sialyl-
transferase than CMP-Neu5Ac. Particularly interesting re-
sults were shown by (R)- and (S)-3, which are derived from
our previous transition state model;[5,6] without changing
the 3,4,5-trihydroxy group pattern of the quinic acid moiety,
excellent inhibition properties were observed and even elim-
ination product (E)-4 exhibited better binding than CMP-
Neu5Ac. Interesting leads for further studies were thus pro-
vided.
Table 1. Affinity of CMP-Neu5Ac (KM) to α(2–6)-sialyltransferase
of rat liver and inhibitions constants (Ki) of 1a–e, 36, (R)-46, (S)-
46, and (E)-47
KM [µm] Ki [µm]
Inhibition mode KM/Ki Ref.
[3]
CMP-Neu5Ac 46
–
–
–
[3]
[3]
[3]
1a
–
–
–
–
–
–
–
–
–
44 ± 7
84 ± 14
Competitive
Competitive
1
1b
0.5
0.03
0.23
2
1c
1.400 ± 300 Competitive
1d
200 ± 20
20 ± 4
Competitive
Competitive
Competitive
Competitive
–
–
–
–
–
–
1e
2
15 ± 3
3
(R)-3
(S)-3
(E)-4
1.6 ± 0.4
30
170
5
Scheme 6. Synthesis of (R)- and (S)-3 and (E)-4. Reagents and con-
ditions: (a) NaBH4 MeOH [ref. 14]. – (b) DIAD, PPh3, BzOH,
THF (94%). – (c) HOAc, H2O, 70 °C (94%). – (d) NaOMe, MeOH;
NaOH, H2O; Ac2O, Pyr (83%). – (e) EtOC(O)Cl, NMP; MeN-
H(OMe), CH2Cl2, –20 °C (73%). – (f) RedAl, Tol/THF, –60°
(60%). – (g) HP(O)(OAll)2; NEt3, CH2Cl2 (92%), (R)/(S)-46 1:1). –
(h) Tetrazole, CH2Cl2; tBuO2H; NEt3 [(R)-48: 91%; (S)-48: 87%]. –
(i) Pd(PPh3)4, Dimedone, THF; NH3, H2O; IR-120(Naϩ) [(R)-3 ϭ
(S)-3 ϭ 88%]. – (j) DBU, THF, 70 °C; Ac2O, Pyr; then (i) (34%)
0.27 ± 0.08 Competitive
10 ± 3
Competitive
Experimental Section
General: Solvents were purified according to the standard proced-
ures. – Melting points (uncorrected): metal block. – NMR (22 °C,
TMS or the resonance of the deuterated solvent was used as in-
ternal standard; solvents: CDCl3, δ ϭ 7.24; CD3OD, δ ϭ 3.315;
D2O, δ ϭ 4.63; for 31P NMR phosphoric acid was used as external
standard; 31P-NMR spectra were broadband 1H decoupled ):
Bruker AC 250 Cryospec, Bruker DRX600, Jeol JNM-GX 400. –
MALDI-MS: Kratos Kompact Maldi 1, 2,5-dihydroxybenzoic acid
(DHB) or 6-aza-2-thiothymine (ATT) were used as matrices. –
FAB-MS: Finnigan MAT 312/AMD 5000; 790 eV, 70 °C. – Optical
rotations: Perkin–Elmer polarimeter 241/MS; 1 dm cell; 20 °C. –
Thin-layer Chromatography: Merck plastic plates, silica gel 60 F254
or Merck glass plates, RP-18; detection by treatment with a solu-
tion of (NH4)6Mo7O24 4 H2O (20 g) and Ce(SO4)2 (0.4 g) in 10%
sulfuric acid (400 mL). – Flash chromatography: J.T. Baker silica
gel 60 (0.040–0.063 mm) at a pressure of 0.3 bar. – Preparative
Scheme 7. Configurational assignment of 46
Eur. J. Org. Chem. 2000, 1745Ϫ1758
1749

C. Schaub, B. Müller, R. R. Schmidt
FULL PAPER
4
3
HPLC separations were performed with an Autochrom System
with a Shimadzu LC 8A preparative pump and a Rainin Dynamax
UV 1 detector at 254 nm. The column used was a Lichrosorb RP-
18, 7 µm, 250 mm ϫ 16 mm (Knauer GmbH, Germany). Mixtures
of acetonitrile and 0.05  triethylammonium bicarbonate (TEAB)
(pH 7.2–7.5) were used as the mobile phase.
13.9 Hz, 1 H, 6eq-H), 3.07 (ddd, J2eq,6eq ϭ 2.6, J2eq,3 ϭ 3.1 Hz,
2J ϭ 16.9 Hz, 1 H, 2eq-H), 3.73 (s, 3 H, COOMe), 4.86 (dd, 3J4,3 ϭ
3
3
5.5 Hz, J4,5 ϭ 7.8 Hz, 1 H, 4-H), 5.35 (ddd, J3,2eq ϭ 3.1 Hz,
3J3,2ax ϭ 4.6 Hz, J3,4 ϭ 5.5 Hz, 1 H, 3-H), 5.66 (ddd, J5,6eq
ϭ
3
3
3
3
4.9 Hz, J5,6ax ϭ 11 Hz, J5,4 ϭ 7.8 Hz, 1 H, 5-H). – C12H16O10S
(352.3): calcd. C 40.91, H 4.58; found C 41.07, H 4.67.
Methyl (1R,3S,4R,5R)-1,5-Di-O-acetyl-4-azido-1,3,5-trihydroxycy-
clohexane-1-carboxylate (9) and Methyl (1S,3S,4S,5R)-1,5-Di-O-
acetyl-3-azido-1,4,5-trihydroxycyclohexane-1-carboxylate (10): To a
solution of the cyclic sulfate 8 (1 g, 2.84 mmol) in DMF (35 mL)
was added lithium azide (278 mg, 5.68 mmol). After stirring for
30 min at 80 °C, the solvent was removed under high vacuum. The
residue was dissolved in THF (40 mL) and conc. sulfuric acid (60
µL) and water (70 µL) were added. The mixture was stirred for
30 min at room temp. and then solid sodium bicarbonate was ad-
ded. The suspension was stirred until neutral, filtered over Celite,
and the filtrate concentrated under vacuum. Flash chromatography
(toluene/acetone, 8:1) of the residue afforded a mixture of the dias-
tereomeric azides as a colourless oil. Separation by MPLC (tolu-
ene/ethyl acetate, 3:1) gave the pure products 10 (561 mg, 62%) as
a colourless oil and 9 (224 mg, 25%) as a colourless oil that crys-
tallised on standing.
Methyl 3,4-O-Cyclohexylidenequinate (5): Compound 5 was syn-
thesised according to a published procedure.[14]
Methyl 3,4-O-Cyclohexylidene-1,5-di-O-acetylquinate (6): To a solu-
tion of the protected methyl quinate 5 (4.7 g, 16.4 mmol) in dry
pyridine (10 mL) and acetic anhydride (5 mL), a catalytic amount
of DMAP was added. After stirring 15 h at room temp., the solu-
tion was coevaporated with toluene (3 ϫ 60 mL). Flash chromato-
graphy (toluene/acetone, 10:1) of the crude product afforded the
diacetate 6 as colourless syrup (6.05 g, quant.). – TLC (toluene/
acetone, 10:1): Rf ϭ 0.26; [α]D ϭ –32.3 (c ϭ 2, CHCl3). – 1H NMR
(250 MHz, CDCl3): δ ϭ 1.53–1.74 (m, 10 H, cyclohexylidene), 2.05/
2.07 (2s, 6 H, 2 Ac), 2.28–2.38 (m, 3 H, 2ax-, 6ax-, 6eq-H), 2.83
(ddd, 2J ϭ16.1 Hz, 3J2eq,3 ϭ 4J2eq,6ed ϭ 2.5 Hz, 1 H, 2eq-H), 3.7 (s,
3 H, COOMe), 4.04 (dd, J4.5 ϭ 7.5 Hz, J4,3 ϭ 5.6 Hz, 1 H, 4-H),
4.40 (ddd, J3,4 ϭ 5.6 Hz, J3,2ax ϭ 4.9 Hz, J3,2eq ϭ 2.5 Hz, 1 H,
3-H), 5.26 (ddd, J5,6ax ϭ 11.5 Hz, J5,4 ϭ 7.5 Hz, J5,6eq ϭ 4.4 Hz,
1 H, 5-H). – C18H26O8 (370.4): calcd. C 58.37, H 7.07; found C
58.54, H 7.00.
9: m.p. 105–106.5 °C, TLC (toluene/acetone, 8:1): Rf ϭ 0.23,
1
[α]D ϭ –22.5 (c ϭ 1, CHCl3). – H NMR (250 MHz, CDCl3): δ ϭ
2.07/2.08 (2 s, 6 H, 2 Ac), 2.10–2.40 (m, 4 H, 2ax-, 2eq, 6ax, 6eq-
H), 3.72 (s, 3 H, COOMe), 3.88 (dd, J4,3 ϭ 5.6 Hz, J4,5 ϭ 3.1 Hz,
1 H, 4 H), 4.17 (dd, J3,2ax ϭ 8.9 Hz, J3,4 ϭ 5.6 Hz, 1 H, 3-H), 5.42
(ddd, J5,6a ϭ 8.46 Hz, J5,6b ϭ 5.6 Hz, J5,4 ϭ 3.1 Hz, 1 H, 5-H). –
C12H17N3O7 (315.3): calcd. C 45.72, H 5.43, N 13.33; found C
45.89, H 5.41, N 13.06.
Methyl 1,5-Di-O-acetylquinate (7): A solution of the peracetylated
compound 6 (3 g, 8.1 mmol) in dry dichloromethane (80 mL) was
cooled to 0 °C. 5 equiv. ethanthiol (2.48 g, 40.5 mmol) and 0.15
equiv. p-toluenesulfonic acid (230 mg, 1.21 mmol) were added. The
mixture was stirred for 16 h at 0–4 °C. The reaction mixture was
neutralised with triethylamine, concentrated under vacuum, and
the residue was extracted with petroleum ether ether (20 mL) to
remove the dithioacetale. The petroleum ether was decanted, and
the crude product was purified by flash chromatography (toluene/
acetone, 4:1Ǟ2:1) to give the diol as a colourless oil (1.7 g,72%)
with minor contaminations of the acetyl migrated product. – TLC
(toluene/acetone, 2:1): Rf ϭ 0.2. The NMR spectra corresponded
with the published data.[30]
10: TLC (toluene/acetone, 8:1): Rf ϭ 0.3, [α]D ϭ 2.9 (c ϭ 1,
1
CHCl3). – H NMR (250 MHz, CDCl3): δ ϭ 1.70–1.86 (m, 2 H,
2ax-, 6ax-H), 2.06/2.11 (2 s, 6 H, 2 Ac), 2.4–2.6 (m, 2H, 2eq-, 6eq-
H), 2.65 (br. s, 1 H, 4-OH), 3.53 (dd, J4,3 ϭ J4,5 ϭ 9.5 Hz, 1 H, 4-
H), 3.6 (m, 1 H, 3-H), 3.70 (s, 3 H, COOMe), 4.92 (ddd, J5,6ax
11.8 Hz, J5,4 ϭ 9.5 Hz, J5.6eq ϭ 4.8 Hz, 1 H, 5-H).
ϭ
Methyl (1S,3S,4S,5R)-1,5-Di-O-acetyl-1,4,5-trihydroxy-3-(trifluo-
roacetamido)cyclohexane-1-carboxylate (11): To a solution of azide
10 (1.24 g, 3.9 mmol) in dry ethyl acetate (40 mL) was added 10%
Pd/C (350 mg), trifluoroacetic acid anhydride (2.48 g, 11.8 mmol),
and sodium bicarbonate (1 g). After two hours of hydrogenation,
triethylamine (2 mL) was added and the suspension was stirred for
additional 30 min. It was filtered through a bed of Celite and the
filtrate was evaporated. Flash chromatography (toluene/acetone,
4:1) of the residue gave the trifluoroacetamide 11 as a colourless
foam (1 g, 66%) besides 0.17 g of recovered starting material. –
TLC (toluene/acetone, 4:1): Rf ϭ 0.14, [α]D ϭ 4.8 (c ϭ 1, CHCl3). –
Methyl 1,5-Di-O-acetyl-3,4-O-sulfonylidenequinate (8): A solution
of diol 7 (1.1 g, 3.8 mmol) and triethylamine (2.1 mL, 15.2 mmol)
in dry dichloromethane (30 mL) was cooled to 0 °C. Over a period
of 20 min, thionyl chloride (1 mL, 13.35 mmol) dissolved in dichlo-
romethane (3 mL) was added. After further 10 min at 0 °C, diethyl
ether (20 mL) and water (20 mL) were added to the dark red solu-
tion. The organic phase was washed with water (2 ϫ 20 mL) and
the combined aqueous layers were extracted with diethyl ether
(40 mL). The organic layers were dried (MgSO4) and concentrated
under vacuum. After drying under high vacuum for 1 h, the yellow
foam was dissolved in ethyl acetate/acetonitrile 1:1 (50 mL) and
was cooled to 0 °C. Then, water (40 mL), a catalytic amount of
RuCl3 H2O, and sodium metaperiodate (1.6 g, 7.6 mmol) were ad-
ded. After 40 min of stirring at 0 °C and 20 min at room temp.,
diethyl ether (80 mL) was added. The aqueous phase was extracted
with diethyl ether (2 ϫ 80 mL) and the combined organic layers
were washed with brine, dried (MgSO4), filtered, and the filtrate
was concentrated. Purification of the residue by flash chromato-
graphy (toluene/acetone, 6:1) afforded the cyclic sulfate 8 as a col-
ourless amorphous solid (0.91 g, 68%). TLC (toluene/acetone, 6:1):
1H NMR (250 MHz, CDCl3): δ ϭ 1.91 (dd, 2J ϭ 13.9 Hz, J6ax,5
ϭ
2
11.3 Hz, 1 H, 6ax-H), 2.03 (dd, J ϭ 14.1 Hz, J2ax,3 ϭ 12.1 Hz, 1
H, 2ax-H), 2.07/2.14 (2 s, 6 H, 2 Ac), 2.55–2.65 (m, 2 H, 2,6ax-H),
2.85 (br. s, 1 H, 4-OH), 3.65 (dd, J4,3 ϭ J4,5 ϭ 9.0 Hz, 1 H, 4-H),
3.71 (s, 3 H, COOMe), 4.12–3.98 (m, 1 H, 3-H), 4.99 (ddd, J5,6ax ϭ
11.3 Hz, J5,4 ϭ 9.0 Hz, J5,6eq ϭ 4.5 Hz, 1 H, 5-H), 6.84 (br. d,
JNH,3 ϭ 7.1 Hz, 1 H, NH). – C14H18F3NO8 0.5 H2O (385.3):
calcd. C 42.65, H 4.86, N 3.55; found C 42.66, H 4.82, N 3.58.
Methyl (1S,3S,4R,5R)-1,5-Di-O-acetyl-1,4,5-trihydroxy-3-(trifluo-
roacetamido)cyclohexane-1-carboxylate (12): A solution of alcohol
Rf ϭ 0.28, [α]D ϭ –33.4 (c ϭ 1, CHCl3). – 1H NMR (250 MHz, 11 (0.92 g, 2.4 mmol) in dry dichloromethane (40 mL) was cooled
CDCl3): δ ϭ 1.78 (dd, J6ax,5 ϭ 11 Hz, 2J ϭ 13.9 Hz, 1 H, 6ax-H), to –18 °C. Abs. pyridine (388 µL, 4.8 mmol) and Tf2O (640 µL,
3
3
2
2.08/2.12 (2 s, 6 H, Ac), 2.55 (dd, J2ax,3 ϭ 4.6 Hz, J ϭ 16.9 Hz,
3.8 mmol) were added successively. After 20 min the mixture was
1 H, 2ax-H), 2.6 (ddd, 4J6eq,2eqϭ 2.6, J6eq,5 ϭ 4.9 Hz, 2J ϭ quenched with sodium bicarbonate solution (40 mL), washed with
3
1750
Eur. J. Org. Chem. 2000, 1745Ϫ1758

Sialyltransferase Inhibitors Based on CMP-Quinic Acid
FULL PAPER
brine (40 mL), and the combined aqueous layers were extracted
with diethyl ether (50 mL). The combined organic extracts were
dried (MgSO4), and evaporation of the solvent afforded the triflate
as a yellow foam [TLC (toluene/acetone, 6:1): Rf ϭ 0.5], which was
used in the following reaction without further purification. The
triflate was dissolved in dry acetonitrile (50 mL) and tetrabutylam-
monium nitrite (1.7 g, 6 mmol) was added. After 30 min the solv-
ents were removed under vacuum. Flash chromatography (toluene/
acetone, 6:1) of the residue yielded the inverted alcohol 12 as a
colourless foam (482 mg, 52%), besides starting material (120 mg,
13%). – TLC (toluene/acetone, 6:1): Rf ϭ 0.32, [α]D ϭ –2.9 (c ϭ 1,
3-NH). – C16H21F3N2O8 (426.4): calcd. C 45.08, H 4.96, N 6.57;
found C 45.08, H 4.97, N 6.48.
Methyl
(1S,3S,4R,5R)-4-Acetamido-5-O-acetyl-1,5-dihydroxy-3-
(trifluoroacetamido)cyclohexane-1-carboxylate (15): To a solution
of compound 14 (0.168 g, 0.40 mmol) in dry methanol (10 mL) 0.5
 sodium methoxide solution in dry methanol (0.5 mL) was added.
After 2 h at room temp. the deacetylation was complete and the
solution was neutralised by addition of Amberlite IR 120 (Hϩ).
The resin was filtered off and the filtrate was concentrated. The
residue was dissolved in dry ethyl acetate (10 mL), Ac2O (47 µL,
0.49 mmol), dry pyridine (32 µL, 0.40 mmol), and a catalytic
amount of DMAP were added. After stirring for 1 h at room temp.
the solvents were removed and the residue coevaported three times
with toluene. Purification by flash chromatography (toluene/acet-
one, 4:1) yielded the alcohol 15 (123 mg, 81%) as a colourless
foam. – TLC (toluene/acetone, 1:1): Rf ϭ 0.5, [α]D ϭ –27.8 (c ϭ 1,
CHCl3). – 1H NMR (250 MHz, CDCl3): δ ϭ1.88–2.33 (m, 4 H,
2eq-, 2ax-, 6eq-, 6ax-H), 1.94/2.04 (2 s, 6 H, O-Ac, N-Ac), 3.72 (s,
1
CHCl3). – H NMR (250 MHz, CDCl3): δ ϭ 1.8–2.4 (m, 4 H, 2eq-,
2ax-, 6eq-, 6ax-H), 2.07/2.13 (2 s, 6 H, 2 Ac), 3.71 (s, 3 H, CO-
OMe), 4.09 (dd, J4,5 ϭ J4,3 ϭ 2.5 Hz, 1 H, 4-H), 4.26–4.37 (m, 1
H, 3-H), 5.02 (ddd, J5,6ax ϭ 12 Hz, J5,6eq ϭ 4.8 Hz, J5,4 ϭ 2.5 Hz,
1 H, 5-H), 6.78 (br. d, JNH,3 ϭ 8.7 Hz, 1 H, NH). – C14H18F3NO8
(385.3): calcd. C 43.64, H 4.71, N 3.64; found C 44.11, H 4.93,
N 3.87.
1 H, 1 OH), 3.78 (s, 3 H, COOMe), 4.16 (ddd, J4,5 ϭ J4,3
ϭ
Methyl (1S,3S,4R,5R)-1,5-Di-O-acetyl-4-azido-1,5-dihydroxy-3-(tri-
fluoroacetamido)cyclohexane-1-carboxylate (13): The alcohol 12
(0.41 g, 1.06 mmol) was dissolved in dry dichloromethane (15 mL)
and cooled to 0 °C. To the stirred solution, dry pyridine (170 µL,
2.12 mmol) and then Tf2O (286 µL, 1.7 mmol) were added slowly.
After 15 min at 0 °C the solution was stirred for 3 h at room temp.
Sodium bicarbonate solution (15 mL) was added and the layers
were separated. The organic layer was washed once with brine and
the combined aqueous layers were extracted with diethyl ether
(1 ϫ 15 mL). The combined organic layers were dried (MgSO4),
filtered, and the filtrate evaporated under vacuum. The triflate was
obtained as a brown foam (TLC: toluene/acetone, 6:1, Rf ϭ 0.5)
which was used directly in the following reaction. It was dissolved
in DMF (10 mL) and lithium azide (0.155 g, 3.18 mmol) was ad-
ded. This suspension was stirred for 45 min at 60 °C, then the DMF
was removed under high vacuum. Flash chromatography (toluene/
acetone, 10:1) of the residue yielded the azide 13 (327 mg, 75%) as
10.6 Hz, J4,NH ϭ 8.6 Hz, 1 H, 4-H), 4.23–4.37 (m, 1 H, 3-H), 5.25
(ddd, J5,6ax ϭ 10.9 Hz, J5,4 ϭ 10.6 Hz, J5,6eq ϭ 5 Hz, 1 H, 5-H),
6.44 (br. d, JNH,4 ϭ 8.6 Hz, 1 H, 4-NH), 8.05 (br. d, JNH,3 ϭ 7.7 Hz,
3-NH). – C14H19F3N2O7 (384.3): calcd. C 43.76, H 4.98, N 7.29;
found C 43.76, H 5.07, N 7.44.
Phosphane 16: To a solution of alcohol 15 (123 mg, 0.32 mmol) in
dry acetonitrile (5 mL) was added diisopropylethylamine[19] (120
µL, 0.7 mmol) and (benzyloxy)chloro(diisopropylamino)phos-
phane (175 mg, 0.64 mmol) under an argon atmosphere. The reac-
tion mixture was stirred for 8 h and flash chromatography (toluene/
acetone, 5:1) of the residue yielded the phosphitamide 16 (180 mg,
91%) as a colourless oil (mixture of diastereoisomers) with minor
contaminations of the phosphitamide reagent. – TLC (toluene/acet-
one, 2:1): Rf ϭ 0.45, 1H NMR (250 MHz, CDCl3): δ ϭ 1.1–1.3 [m,
12 H, 2 CH(CH3)2], 1.7–2.0 (m, 8 H, 2ax-, 6ax-H, 3 Ac), 2.4–2.6
(m, 2 H, 2eq-, 6eq-H), 3.52/3.59 (2 s, 3 H, COOMe) 3.60–3.78 [m,
2 H, 2 CH(CH3)2], 3.99–4.20 (m, 1 H, 4-H), 4.20–4.40 (m, 1 H, 3-
H), 4.22–4.70 (m, 2 H, CH2–Ph), 5.12–5.33 (m, 1 H, 5-H), 5.83/
5.94 (2 br. d, JNH,4 ϭ 8.6 Hz, 4-NH), 7.22–7.39 (m, 5 H, Ph), 8.27/
8.33 (2 br. d, JNH,3 ϭ 7.7 Hz, 3-NH).
a colourless foam. – TLC (toluene/acetone, 4:1): Rf ϭ 0.48, [α]D
ϭ
10.1 (c ϭ 1, CHCl3). – 1H NMR (250 MHz, CDCl3): δ ϭ 1.89 (dd,
2J ϭ 13.8 Hz, J6ax,5 ϭ 11.2 Hz, 1 H, 6ax-H), 2.08/2.13 (2 s, 6 H, 2
Ac), 2.18 (dd, 2J ϭ 14 Hz, J2ax,3 ϭ 11.8 Hz, 1 H, 2ax-H), 2.54 (ddd,
4
2J ϭ 14 Hz, J2eq,3 ϭ 4.3 Hz, J2eq,6eq ϭ 2.6 Hz, 1 H, 2eq-H), 2.66
2
4
(ddd, J ϭ 13.8 Hz, J6eq,5 ϭ 4.6 Hz, J6eq,2eq ϭ 2.6 Hz, 1 H, 6eq-
H), 3.71 (s, 3 H, COOMe), 3.72 (dd, 3J4,3 ϭ 10.3 Hz, 3J4,5 ϭ 9.3 Hz,
1 H, 4-H), 3.77–3.89 (m, 1 H, 3-H), 5.04 (ddd, J5,6ax ϭ 11.2 Hz,
N-Acetyl-2Ј,3Ј-di-O-acetylcytidine (17): Compound 17 was synthe-
sized as previously described.[3]
Phosphate 18: To a solution of the phosphitamide 16 (180 mg,
0.29 mmol) and cytidine 17[3,8] (121 mg, 0.33 mmol) in dry aceto-
nitrile (5 mL) was added tetrazole (32 mg, 0.45 mmol) under an
argon atmosphere. After stirring for 18 h, tBuOOH (3  in toluene,
0.25 mL) was added, and the solution was stirred for 3 h. Then
J5,4 ϭ 9.3 Hz, J5,6eq ϭ 4.6 Hz, 1 H, 5-H), 6.72 (br. d, JNH,3
7.7 Hz, 1 H, NH). – C14H17F3N4O7 (410.3): calcd. C 40.98, H 4.18,
N 13.65; found C 40.79, H 4.24, N 13.35.
ϭ
Methyl (1S,3S,4R,5R)-4-Acetamido-1,5-di-O-acetyl-1,5-dihydroxy-
3-(trifluoroacetamido)cyclohexane-1-carboxylate (14): To a solution triethylamine was added and the solvents were evaporated under
of azide 13 (0.27 g, 0.65 mmol) in methanol (35 mL) 10% Pd/C
(80 mg) was added. After 30 min of hydrogenation, Ac2O (1.5 mL)
and pyridine (3 mL) were added, and the suspension was stirred
overnight. The suspension was filtered over Celite and concentrated
under vacuum. The residue was coevaporated with toluene three
times and purification by flash chromatography (toluene/acetone,
4:1) afforded the acetamide 14 (0.20 g, 72%) as a colourless foam. –
TLC (toluene/acetone, 4:1): Rf ϭ 0.08, [α]D ϭ –32.5 (c ϭ 1,
vacuum. The residue was purified by flash chromatography (tolu-
ene/acetone, 1:2) to yield the protected phosphate contaminated
with a small amount of cytidine 17. A suspension of this mixture
and 10% Pd/C (15 mg) in methanol/ethyl acetate (1:1, 10 mL) was
hydrogenated for 15 min. The suspension was neutralised with
NEt3, filtered through Celite and evaporated. Flash chromato-
graphy (ethyl acetate/methanol/NEt3, 4:1 ϩ 1%) of the residue and
lyophylisation afforded the triethylammonium salt 18 (85 mg, 32%)
CHCl3). – 1H NMR (250 MHz, CDCl3): δ ϭ 1.8–2.0 (m, 1 H, 6ax- as a colourless foam. – TLC (ethyl acetate/methanol, 3:1 ϩ 1%
2
H), 1.88/2.03 (2 s, 6 H, 2 O-Ac), 2.05 (dd, J ϭ 13.7 Hz, J2ax,3
ϭ
NEt3) Rf ϭ 0.14, [α]D ϭ 13.9 (c ϭ 1, methanol). – 1H NMR
12 Hz, 1 H, 2ax-H), 2.13 (s, 3 H, N-Ac), 2.50–2.66 (m, 2 H, 2,6eq-
H), 3.68 (s, 3 H, COOMe), 4.13–4.33 (m, 2 H, 3,4-H), 5.03 (ddd, NCH2CH3), 1.80–2.22 (m, 2 H, 2axЈЈ-, 6axЈЈ-H), 1.87/1.93/2.08/
J5,6ax ϭ 11.73, J5,4 ϭ 10 Hz, J5,6eq ϭ 4.6 Hz, 1 H, 5-H), 6.05 (br. 2.11/2.17 (5 s, 15 H, 5 Ac), 2.46–2.64 (m, 2 H, 6eqЈЈ-, 2eqЈЈ-H),
d, JNH,4 ϭ 8.63 Hz, 1 H, 4-NH), 8.52 (br. d, JNH,3 ϭ 8.5 Hz, 1 H, 3.18 (q, J ϭ 7.3 Hz, 6 H, NCH2CH3) 3.77 (s, 3 H, COOMe), 4.02
(250 MHz, [D4]methanol): δ ϭ 1.30 (t, J ϭ 7.3 Hz, 9 H,
Eur. J. Org. Chem. 2000, 1745Ϫ1758
1751

C. Schaub, B. Müller, R. R. Schmidt
(dd, J4ЈЈ,3ЈЈ ϭ J4ЈЈ,5ЈЈ ϭ 10.7 Hz, 1 H, 4ЈЈ-H), 4.24–4.44 (m, 4 H, 4Ј-, hydride (2:1, 18 mL) a catalytic amount of DMAP was added.
FULL PAPER
5a,bЈ-, 3ЈЈ-H), 5.26 (ddd, J5ЈЈ,4ЈЈ ϭ J5ЈЈ,6axЈЈ ϭ 10.7 Hz, J5ЈЈ,6eqЈЈ
4.8 Hz, 1 H, 5ЈЈ-H), 5.55 (dd, J2Ј,3Ј ϭ 5.2 Hz, J2Ј,1Ј ϭ 4.35 Hz, 1 H,
ϭ
After stirring for 14 h at room temp., the solution was coevaporated
three times with toluene. Purification of the residue by flash chro-
2Ј-H), 5.60 (dd, J3 Ј,2Ј ϭ 5. 2 Hz, J3Ј,4Ј ϭ 4.9 Hz, 1 H, 3Ј-H), 6.21 matography (toluene/ethyl acetate, 25:1 Ǟ 20:1) affords compound
(d, J1Ј,2Ј ϭ 4.35 Hz, 1 H, 1Ј-H), 7.52 (d, J5,6 ϭ 7.5 Hz, 1 H, 5-
20 (9.5 g, 82%) as a colourless oil which solidifies on standing. m.p.
H), 8.54 (d, J6,5 ϭ 7.5 Hz, 1 H, 6-H). – 31P NMR (161.7 MHz, 68–70 °C, TLC (toluene/ethyl acetate, 8:1): Rfϭ 0.22, [α]D ϭ –20.3
[D4]methanol): δ ϭ –2.93. – MS (MALDI, negative mode, matrix:
(c ϭ 1, CHCl3). – 1H NMR (250 MHz, CDCl3): δ ϭ 1.30–1.70 (m,
ATT): m/z: 814 [M – NHEt3]–. – C35H52F3N6O17P 2 H2O (916.8): 11 H, cyclohexylidene-H, 6a-H), 2.03 (s, 3 H, Ac), 2.24–2.37 (m, 2
calcd. C 44.12, H 5.92, N 8.82; found C 44.22, H 5.99, N 8.69.
H, 2a-,6b-H), 2.71 (ddd, 2J ϭ 16 Hz, J2b,3 ഠ 4J2b,6b ഠ 2.8 Hz, 1 H,
2b-H), 3.71 (s, 3 H, COOMe), 3.80 (ddd, J5,6a ϭ 11.3 Hz, J5,4
6.9 Hz, J5,6b ϭ 4.3 Hz, 1 H, 5-H), 3.98 (dd, J4,5 ഠ J4,3 ഠ 6.3 Hz, 1
H, 4-H), 4.12–4.19 (m, 2 H, CH2CHϭCH2), 4.37 (ddd, J3,4
J3,2a ഠ 5.5 Hz, J3,2b ϭ 3.2 Hz, 1 H, 3-H), 5.13–5.32 (m, 2 H,
CH2CHϭCH2), 5.82–5.96 (m, 1 H, CH2CHϭCH2). – C19H28O7
(368.4): calcd. C 61.94, H 7.66; found C 61.65, H 7.65.
ϭ
Lithium Salt 1d: To a solution of the protected triethylammonium
salt 18 (50 mg, 0.055 mmol) in dry methanol (5 mL) was added a
sodium methoxide solution in dry methanol (0.5 , 0.2 mL). After
stirring for 5 h at room temp. the solution was neutralised with
Amberlite IRC 176 (Hϩ), filtered, and evaporated. The residue was
dissolved in water/methanol 1:1 (4 mL) and lithium hydroxide
(40 mg) was added. After stirring for 20 h at room temp., the solu-
tion was evaporated and lyophilised from water. The mixture of a
ഠ
Methyl 1-O-Acetyl-3,4-O-cyclohexylidene-5-O-(hydroxyethyl)quin-
ate (21): A solution of allyl compound 20 (9 g, 24.4 mmol) in
lactam and amine 1d was separated using preparative HPLC (0.05 dichloromethane/methanol (1:1, 60 mL) was cooled to –78 °C. At
 triethylammoniumbicarbonate buffer). Ion exchange with Am-
berlite IR 120 (Liϩ) yielded the lithium salt of 1d (20 mg, 67%)
as a colourless foam. Further purification could be achieved by
precipitation with ethanol from water. – TLC (ethyl acetate/meth-
this temperature, ozone was bubbled through the solution for
25 min until the blue colour stayed. After warming to –60 °C, so-
dium borohydride (1.8 g, 48.8 mmol) was added stepwise and the
solution was allowed to come to 0 °C. The solution was concen-
anol/1  NH4CH3CO2, 1:1:1): Rf ϭ 0.33, [α]D ϭ 2.8 (c ϭ 0.4, trated under vacuum after 3 h. The resulting suspension was re-
H2O). – 1H NMR (600 MHz, D2O): δ ϭ 1.83 (dd, J ϭ 14 Hz, solved in ethyl acetate and saturated ammonium chloride solution.
J6axЈЈ,5ЈЈ ϭ 10.3 Hz, 1 H, 6axЈЈ-H), 2.06 (m, 1 H, 2axЈЈ-H), 2.09 (s, The phases were separated and the aqueous phase was extracted
3 H, N-Ac), 2.56 (m, 1 H, 6eqЈЈ-H), 2.66 (m, 1 H, 2eqЈЈ-H), 3.53
three times with ethyl acetate. The combined organic phases were
(ddd, J3ЈЈ,2axЈЈ ϭ 13 Hz, J3ЈЈ,4ЈЈ ϭ 10.3 Hz, J3ЈЈ,2eqЈЈ ϭ 3.9 Hz, 1 H, dried with MgSO4, concentrated, and the residue was purified by
3
3ЈЈ-H), 3.88 (dd, J4ЈЈ,3ЈЈ
(ddd, J5ЈЈ,4ЈЈ ϭ J5ЈЈ,6axЈЈ ϭ 10.3 Hz, J5ЈЈ,6eqЈЈ ϭ 4.3 Hz, H, 5ЈЈ-H), thyl compound 21 (6.39 g, 73%) as a colourless oil. – TLC (toluene/
ϭ
3J4ЈЈ,5ЈЈ ϭ 10.3 Hz, 1 H, 4ЈЈ-H), 3.98 flash chromatography (toluene/acetone, 4:1) to yield the hydroxye-
1
4.18–4.22 (m, 1 H, 5aЈ-H), 4.23–4.28 (m, 2 H, 4Ј-, 5bЈ-H), 4.30–
acetone, 4:1): Rf ϭ 0.14, [α]D ϭ –27.4 (c ϭ 2, CHCl3). – H NMR
4.36 (m, 2 H, 2Ј-, 3Ј-H), 5.98 (d, J1Ј,2Ј ϭ 3.5 Hz, 1 H, 1Ј-H), 6.11 (250 MHz, CDCl3): δ ϭ 1.30–1.70 (m, 11 H, cyclohexylidene-H,
2
(d, J5,6 ϭ 7.6 Hz, 1 H, 5-H), 7.96 (d, J6,5 ϭ 7.6 Hz, 1 H, 6-H). – 6a-H), 2.04 (s, 3 H, Ac), 2.29 (ddd, J ϭ 16.1 Hz, J6b,5 ϭ 4.3 Hz,
13C NMR (150.9 MHz, D2O): δ ϭ 22.18 (Ac–CH3), 36.79 (C-2ЈЈ),
41.08 (C-6ЈЈ), 50.05 (C-3ЈЈ), 56.52 (C-4ЈЈ), 64.45 (C-5Ј), 67.42 (C 1 H, 2a-H), 2.75 (ddd, J ϭ 16.1 Hz, J2b,3 ϾϾ J2b,6b ϾϾ 2.7 Hz,
5ЈЈ), 69.16 (C-3Ј), 74.07 (C-2‘), 80.7 (C-1ЈЈ), 82.8 (C-4Ј), 89.22 (C- 1 H, 2b-H), 3.64–3.84 (m, 5 H, CH2CH2OH, 5-H), 3.72 (s, 3 H,
J
6b,2b ϭ 2.7 Hz, 1 H, 6b-H), 2.34 (dd, 2J ϭ 16.1 Hz, J2a,3 ϭ 4.8 Hz,
2
4
1Ј), 96.44 (C-6), 141.55 (C-5), 157.71(C-4), 166.14 (C-2), 175.49, COOMe), 3.98 (dd, J4,5 ϭ 7.0 Hz, J4,3 ϭ 5.9 Hz, 1 H, 4-H), 4.38
177.09 (2 CϭO). – 31P NMR (161.7 MHz, D2O): δ ϭ –3.37. – MS (ddd, J3,4 ϭ 5.9 Hz, J3,2a ϭ 4.8 Hz, J3,2b ϭ 3.0 Hz, 1 H, 3-H). –
(MALDI, negative mode, matrix: ATT): m/z: 537 [M – Li]– 543.2 C18H28O8 1 H2O (372.4) calcd. C 55.37, H 7.74; found C 55.87,
for C18H27LiN5O12P.
H 7.30.
Methyl 5-O-Allyl-3,4-O-cyclohexylidenequinate (19): To a solution
of compound 5[14] (10 g, 34.9 mmol) in dry dichloromethane
(20 mL) and dry cyclohexane (50 mL) was added allyl trichloroace-
Methyl 5-O-(2-acetoxyethyl)-1-O-acetyl-3,4-O-cyclohexylidenequin-
ate (22): To a solution of hydroxyethyl compound 21 (6.24 g,
16.75 mmol) in dry ethyl acetate (10 mL) was added pyridine/acetic
timidate (14.14 g, 69.8 mmol) and trifluoromethanesulfonic acid anhydride (2:1, 15 mL). After stirring for about 12 h the solution
(0.2 mL) at 0 °C. After stirring for 2 h at 0 °C and 3 h at room was coevaporated three times with toluene. The residue was puri-
temp. the reaction was quenched by addition of a sodium bicarbon-
ate solution. Diethyl ether (50 mL) was added and the phases were
separated. The organic phase was washed with sodium bicarbonate
solution and water, dried with MgSO4, and concentrated under va-
cuum. The resulting oil was suspended in hexane/toluene (1:1,
25 mL) and the precipitated trichloroacetamide was filtered off.
The filtrate was concentrated and the residue was purified by flash
chromatography (toluene/ethyl acetate, 10:1 Ǟ 5:1) to yield com-
pound 19 (10.24 g, 90%) as a colourless oil. – TLC (toluene/ethyl
fied by flash chromatography (toluene/acetone, 10:1) to yield com-
pound 22 (6.39 g, 92%) as a colourless oil, which solidifies on
standing. m.p. 71–72 °C, TLC (toluene/acetone, 4:1): Rf ϭ 0.48,
[α]D ϭ –13.5 (c ϭ 1, CH2Cl2). – 1H NMR (250 MHz, CDCl3): δ ϭ
1.30–1.70 (m, 11 H, cyclohexylidene-H, 6a-H), 2.04/2.06 (2 s, 6 H,
2
2 Ac), 2.27 (ddd, J ϭ 13.7 Hz, J6b,5 ϭ 4.3 Hz, J6b,2b ϭ 2.5 Hz, 1
2
H, 6b-H), 2.32 (dd, J ϭ 16.1 Hz, J2a,3 ϭ 4.8 Hz, 1 H, 2a-H), 2.75
2
4
(ddd, J ϭ 16.1 Hz, J2b,3 ഠ J2b,6b ഠ 2.8 Hz, 1 H, 2b-H), 3.71 (s, 3
H, COOMe), 3.72–3.82 (m, 2 H, CH2CH2OAc, 5-H), 3.88–4.00 (m,
acetate, 6:1): Rf ϭ 0.17, [α]D ϭ –45.0 (c ϭ 1 in CHCl3). – 1H NMR 2 H, CH2CH2OAc, 4-H), 4.20 (dd, J ϭ 4.5 Hz, J ϭ 5.4 Hz, 2 H,
(250 MHz, CDCl3): δ ϭ 1.38 (m, 2 H, cyclohexylidene-H), 1.53–
CH2CH2OAc), 4.36 (ddd, J3,4 ϭ 5.6 Hz, J3,2a ϭ 4.8 Hz, J3,2b
ϭ
1.77 (m, 8 H, cyclohexylidene-H, 2.10–2.39 (m, 4 H, 2a-, 2b-, 6a-,
3 Hz, 1 H, 3-H). – C20H30O9 (414.5) calcd. C 57.96, H 7.30; found
6b-H), 3.56 (s, 1 H, 1-OH), 3.76 (s, 3 H, COOMe), 3.79–3.88 (m, C 57.79, H 7.25.
1 H, CH2CHϭCH2), 4.04 (dd, J4,5 ϭ 7 Hz, J4,3 ϭ 5.5 Hz, 1 H, 4-
H), 4.06–4.30 (m, 3 H, 3-, 5-H, CH2CHϭCH2), 5.1–5.3 (m, 2 H,
CH2CHϭCH2), 5.82–5.90 (m, 1 H, CH2CHϭCH2).
Methyl 5-O-(2-Acetoxyethyl)-1-O-acetylquinate (23): A solution of
compound 22 (200 mg, 0.48 mmol) in acetic acid (90%, 10 mL) was
stirred for 1 h at 60–70 °C. The acetic acid was removed under
vacuum and the residue was purified by flash chromatography
(toluene/acetone, 2:1) to afford 23 (160 mg, quant.) as a colourless
Methyl 1-O-Acetyl-5-O-allyl-3,4-O-cyclohexylidenequinate (20): To
a solution of alcohol 19 (10.24 g, 31.4 mmol) in pyridine/acetic an-
1752
Eur. J. Org. Chem. 2000, 1745Ϫ1758

Sialyltransferase Inhibitors Based on CMP-Quinic Acid
FULL PAPER
oil. – TLC (toluene/acetone, 2:1): Rf ϭ 0.23, [α]D ϭ –29.3 (c ϭ 1, anol). – 1H NMR (250 MHz, [D4]methanol): δ ϭ 1.30 (t, J ϭ
CHCl3). – 1H NMR (250 MHz, CDCl3): δ ϭ 1.60 (dd, 2J ϭ 7.3 Hz, 9 H, NCH2CH3), 1.98/2.05/2.06/2.08/2.11/2.17 (6 s, 18 H,
13.5 Hz, J6a,5 ϭ 10.8 Hz, 1 H, 6a-H), 2.04/2.06 (2 s, 6 H, 2 Ac), 6 Ac), 2.24–2.62 (m, 4 H, 2a,bЈЈ-, 6a,bЈЈ-H), 3.19 (q, J ϭ 7.3 Hz, 6
2
2.00–2.14 (m, 1 H, 2a-H), 2.45 (ddd, J ϭ 13.5 Hz, J6b,5 ϭ 4.0 Hz,
H, NCH2CH3), 3.62–3.71 (m, 2 H, CH2CH2OAc), 3.74 (s, 3 H,
COOMe), 3.76–3.85 (m, 1 H, 5ЈЈ-H), 4.11 (t, J ϭ 5.0 Hz, 2 H,
CH2CH2OAc), 4.09–4.15 (m, 1 H, 5aЈ-H),4.20–4.28 (m, 1 H, 5bЈ-
H), 4.40 (m, 1 H, 4Ј-H), 5.17 (dd, J4ЈЈ,5ЈЈ ϭ 5.3 Hz, J4ЈЈ,3ЈЈ ϭ 3.2 Hz,
J6b,2b ϭ 2.9 Hz, 1 H, 6b-H), 2.68 (ddd, 2J ϭ 15.7 Hz, J2b,3
ഠ
4J2b,6b ഠ 3.1 Hz, 1 H, 2b-H), 3.52 (dd, J4,5 ϭ 9 Hz, J4,3 ϭ 3.4 Hz,
1 H, 4-H), 3.60–3.73 (m, 1 H, CH2CH2OAc), 3.70 (s, 3 H, CO-
OMe), 3.75–3.88 (m, 2 H, CH2CH2OAc, 5-H), 4.08–4.33 (m, 3 H, 1 H, 4ЈЈ-H), 5.36–5.43 (m, 1 H, 3ЈЈ-H), 5.45–5.52 (m, 2 H, 2Ј-, 3Ј-
CH2CH2OAc, 3-H). – C14H22O9 0.25 H2O (334.3) calcd. C 49.63, H), 6.22 (d, J1Ј,2Јϭ 4.6 Hz, 1 H, 1Ј-H), 7.57 (d, J5,6 ϭ7.5 Hz, 1 H,
H 6.69; found C 49.88, H 6.58.
5-H), 8.46 (d, J6,5 ϭ 7.5 Hz, 1 H, 6-H). – 31P NMR (161.7 MHz,
[D4]methanol): δ ϭ –3.48 (s, phosphate). – MS (MALDI, negative
Methyl 5-O-(2-Acetoxyethyl)-3,4-di-O-acetylquinate (24): To a solu-
tion of the diacetyl compound 23 (261 mg, 0.78 mmol) in dry meth-
anol (10 mL) was added a solution of sodium methoxide in dry
methanol (0.5 , 0.5 mL). After 1.5 h at room temp. the solution
was neutralised by addition of Amberlite IR 120 (Hϩ), and concen-
trated under vacuum. The residue was dissolved in dry ethyl acetate
(10 mL), and acetic anhydride (94.5 µL, 1 mmol), pyridine (65 µL,
0.8 mmol), and a catalytic amount of DMAP were added. After
stirring for about 12 h the solvents were removed under vacuum,
and the residue was purified by flash chromatography (toluene/
acetone, 4:1) to yield the selectively acetylated compound 24
(205 mg, 70%) as a colourless oil. – TLC (toluene/acetone, 2:1):
Rf ϭ 0.46, [α]D ϭ –38.1 (c ϭ 1, CHCl3) – 1H NMR (250 MHz,
CDCl3): δ ϭ 1.94–2.21 (m, 4 H, 2a,b-, 6a,b-H), 2.04/2.06 (2 s, 9 H,
3 Ac), 3.71 (t, J ϭ 4.8 Hz, 2 H, CH2CH2OAc), 3.76 (s, 3 H, CO-
OMe), 3.93 (ddd, J5,4 ഠ J5,6a ഠ 9.1 Hz, J5,6b ϭ 4.3 Hz, 1 H, 5-H),
mode, matrix: ATT): m/z: 806 [M
–
NHEt3]–.
–
C37H57N4O20P 2 H2O (908.6) calcd. C 47.04, H 6.51, N 5.93;
found C 47.12, H 6.40, N 6.01.
Phosphate 1e: To a solution of the triethylammonium salt of com-
pound 26 (50 mg, 0.055 mmol) in dry methanol (3 mL) was added
a solution of sodium methoxide in dry methanol (0.5 , 0.5 mL).
After 2 h the solution was neutralised with Amberlite IRC 176
(Hϩ) and evaporated. The residue was dissolved in methanol/water
(1:1, 5 mL) and NaOH (1 , 0.5 mL) was added. After stirring
overnight the solution was neutralised with IRC 176 (Hϩ), the pH
value was adjusted to 8 with NaOH, and the solvents were removed
by lyophilisation. The residue was purified by a Biogel P2 column
(25 ϫ 2.5 cm, water, flow 25 mL/h) to afford compound 1e (19 mg,
59%) as a colourless lyophilisate. – TLC (ethyl acetate/methanol/1
 CH3CO2NH4, 1:1:1): Rf ϭ 0.64, [α]D ϭ –21.0 (c ϭ 1, H2O). –
1H NMR (600 MHz, D2O): δ ϭ 1.60–1.70 (m, 1 H, 2aЈЈ-H), 1.90–
2.05 (m, 1 H, 6aЈЈ-H), 2.25–2.35 (m, 1 H, 6bЈЈ-H), 2.50–2.60 (m, 1
H, 2bЈЈ-H), 3.40–3.55 (m, 2 H, HOCH2CH2O, 4ЈЈ-H), 3.58–3.70
(m, 3 H, HOCH2CH2O), 3.78–3.88 (m, 1 H, 3ЈЈ-H), 4.00–4.10 (m,
2 H, 5aЈ-, 3Ј-H), 4.10–4.13 (m, 1 H, 4Ј-H), 4.16–4.25 (m, 3 H, 2Ј-,
4.03–4.20 (m, 2 H, CH2CH2OAc), 4.97 (dd, J4,5 ϭ 8.7 Hz, J4,3
ϭ
3.3 Hz, 1 H, 4-H), 5.39 (ddd, J3,2a ϭ 4.9 Hz, J3,4 ഠ J3,2b ഠ 3.5 Hz,
1 H, 3-H). – C16H24O10 0.25 H2O (376.4) calcd. C 50.45, H 6.49;
found C 50.59, H 6.48.
(Benzyloxy)(diisopropylamino)[methyl 5-O-(2-acetoxyethyl)-3,4-di-
O-acetylquinate]phosphane (25): To a solution of the alcohol 24
(200 mg, 0.53 mmol) in dry acetonitrile (7 mL) was added diisopro-
pylethylamine (190 µL, 1.11 mmol) and (benzyloxy)chloro(diiso-
propylamino)phosphane[19] (290 mg, 1.06 mmol). The solvents
were removed under vacuum after 18 h stirring at room temp. and
the residue was purified by flash chromatography (toluene/acetone,
12:1) to yield the phosphitamide 25 (210 mg, 65%) as a mixture of
diastereoisomers. – TLC (toluene/acetone, 2:1): Rf ϭ 0.70–1H
NMR (250 MHz, CDCl3): δ ϭ 1.08–1.32 [m, 12 H, 2 CH(CH3)2]
1.96–2.19 (m, 2 H, 2a-, 6a-H), 1.97/2.02/2.04/2.05 (4 s, 9 H, 3 Ac),
2.39–2.52 (m, 2 H, 2b-, 6b-H), 3.48–3.53 (m, 1 H, CH2CH2OAc),
3.55–3.79 [m, 4 H, CH2CH2OAc, 2 CH(CH3)2, 5-H], 3.59/3.62 (2
s, 3 H, COOMe), 3.99–4.03/4.07–4.12 (2 m, 2 H, CH2CH2OAc),
4.48–4.71 (m, 2 H, CH2Ph), 5.13–5.20 (m, 1 H, 4-H), 5.28–5.36 (m,
1 H, 3-H), 7.21–7.39 (m, 5 H, Ph).
5bЈ-, 5ЈЈ-H), 5.86 (d, J1Ј,2Ј ϭ 4.0 Hz, 1 H, 1Ј-H), 6.03 (d, J5,6
ϭ
7.5 Hz, 1 H, 5-H), 7.88 (d, J6,5 ϭ 7.5 Hz, 1 H, 6-H). – 13C NMR
(150.9 MHz, D2O): δ ϭ 38.3 (6ЈЈ-C), 38.5 (2ЈЈ-C), 62.2 (HOCH2-
CH2O), 65.6 (d, 2JC,P ϭ 5.3 Hz, 5Ј-H), 70.4 (2Ј-C), 70.7 (3Ј-C), 71.8
(HOCH2CH2O), 75.4 (5ЈЈ-C), 75.6 (4ЈЈ-C), 76.7 (3ЈЈ-C), 84.1 (d,
3JC,P ϭ 7.9 Hz, 4Ј-H), 84.3 (1ЈЈ-C), 90.6 (1Ј-C), 97.8 (5-C), 142.9
(6-C), 158.9 (4-C), 167.4 (2-C), 175.54 (CϭO). – 31P NMR
(161.7 MHz, D2O): δ ϭ –2.77 (s, phosphate). – MS (MALDI, nega-
tive mode, matrix: ATT): m/z: 538 [M – 2 Na ϩ H]–, 585.1 for
C18H26N3Na2O14P.
Methyl (1R,4R,5R)-1,5-Di-O-acetyl-1,4,5-trihydroxycyclohex-2-ene-
1-carboxylate (27): To a solution of cyclic sulfate 8 (2 g, 5.67 mmol)
in dry THF (50 mL) was added DBU (1.02 mL, 6.8 mmol) and the
solution was heated for 30 min to 70 °C. The reaction mixture was
cooled to room temp. and was treated with sulfuric acid (0.05 mL,
0.94 mmol) and water (0.1 mL) for 1 h to remove the sulfate group.
Solid sodium bicarbonate and MgSO4 were added, and the suspen-
sion was stirred until neutral. The suspension was filtered over Cel-
ite, the residue was washed carefully with acetone and the solvents
were removed under vacuum. Flash chromatography (toluene/acet-
one, 6:1) of the residue yielded the eliminated product 27 (1.35 g,
88%) as a colourless foam. – TLC (toluene/acetone, 2:1): Rf ϭ 0.48,
Phosphate 26: To a solution of phosphitamide 25 (210 mg,
0.34 mmol) and cytidine 17[3,8] (138 mg, 0.37 mmol) in dry aceton-
itrile (7 mL), tetrazole (38 mg, 0.54 mmol) was added under argon.
After 4 h stirring at room temp. tBuOOH (0.11 mL, 0.61 mmol, 5.5
 in nonane) was added. After 1.5 h, 2–3 drops of triethylamine
were added and then the solution was concentrated under vacuum.
The residue was purified by flash chromatography (toluene/acet-
one, 2:1 Ǟ 1:1) and afforded 220 mg of a mixture of benzyl pro- [α]D ϭ 2.5 (c ϭ 1, CHCl3). – 1H NMR (250 MHz, CDCl3): δ ϭ
tected phosphate contaminated with cytidine 17. This mixture was
dissolved in methanol (15 mL) and Pd/C (10%, 40 mg) was added.
After 25 min of hydrogenation at room temp. the catalyst was fil-
2.03 (dd, J6a,6b ϭ 13.6 Hz, J6a,5 ϭ 12.2 Hz, 1 H, 6a-H), 2.07/2.10
(2 s, 6 H, 2 Ac), 2.42 (ddd, J6b,6a ϭ 13.6 Hz, J6b,5 ϭ 4 Hz, 4J6b,2
1.9 Hz, 1 H, 6b-H), 3.73 (s, 3 H, COOMe), 4.26 (ddd, J4,5 ϭ 8.2 Hz,
ϭ
tered off, triethylamine was added, and the solvent was removed J4,3 ഠ J4,2 ഠ 2.2 Hz, 1 H, 4-H), 5.03 (ddd, J5,6a ϭ 12.2 Hz, J5,4
ϭ
under vacuum. The residue was purified by flash chromatography
(ethyl acetate/methanol, 3:1 ϩ 1% NEt3) to yield compound 26
(190 mg, 62%) as a colourless lyophilisate. – TLC (ethyl acetate/
methanol, 3:1ϩ1% NEt3): Rf ϭ 0.13, [α]D ϭ 7.2 (c ϭ 0.5, meth-
8.2 Hz, J5,6b ϭ 4 Hz, 1 H, 5-H), 5.94 (dd, J3,2 ϭ 10.1 Hz, J3,4
ϭ
2.15 Hz, 1 H, 3-H), 6.13 (ddd, J2,3 ϭ 10.1 Hz, 4J2,6b ഠ 4J2,4 ഠ 2 Hz,
1 H, 2-H). – C12H16O7 (272.3): calcd. C 52.94, H 5.92; found C
52.73, H 5.91.
Eur. J. Org. Chem. 2000, 1745Ϫ1758
1753

C. Schaub, B. Müller, R. R. Schmidt
FULL PAPER
Methyl
(1R,5R)-1,5-Di-O-acetyl-1,5-dihydroxy-3-oxocyclohex-2-
1.99/1.98 (3 s, 9 H, 3 Ac), 2.0–2.3 (m, 2 H, 6a,b-H), 3.73 (s, 3 H,
ene-1-carboxylate (28): To a solution of compound 27 (1.17 g, COOMe), 4.80–4.91 (m, 1 H, 4-H), 5.22 (ddd, J5,6a ϭ 11.1 Hz,
4.22 mmol) in dry dichloromethane (60 mL), Dess–Martin J5,4 ഠ J5,6b ഠ 4.2 Hz, 1 H, 5-H), 5.54 (br. d, JNH,4 ϭ 5.5 Hz, 1 H,
periodinane was added (2.14 g, 5.06 mmol) and the white suspen-
sion was stirred for 30 min at room temp. Saturated sodium bicar-
bonate solution (100 mL) and sodium thiosulfate (15 g) were added
and the mixture was stirred vigorously for 30 min. The phases were
separated and the organic phase was washed with brine, dried with
MgSO4, and concentrated under vacuum. The residue was purified
by flash chromatography (toluene/acetone, 8:1) to afford the ketone
28 (0.94 g, 83%). – TLC (toluene/acetone, 4:1): Rf ϭ 0.6. – 1H
NH), 5.92 (dd, J3,2 ϭ 10 Hz, J3,4 ϭ 5 Hz, 1 H, 3-H), 6.23 (ddd,
J2,3 ϭ 10 Hz, J2,6a
(313.3) calcd. C 53.67, H 6.11, N 4.47; found C 53.21, H 6.15,
N 4.81.
4
ഠ
4J2,4 ഠ 1.2 Hz, 1 H, 2-H). – C14H19NO7
Methyl (1R,4S,5R)-1,5-Di-O-acetyl-4-azido-1,5-dihydroxycyclohex-
2-ene-1-carboxylate (32): To a solution of alcohol 27 (0.6 g,
2.2 mmol) in dry dichloromethane (20 mL) were added triethylam-
ine (368 µL, 2.64 mmol) and mesyl chloride (204 µL, 2.64 mmol)
at 0 °C. After 20 min stirring at 0 °C, sodium bicarbonate solution
(15 mL) was added, the phases were separated, and the organic
phase was washed with brine. The combined aqueous phases were
extracted two times with diethyl ether, and the combined organic
phases were dried with MgSO4. After removing the solvents under
vacuum the mesylate (Rf ϭ 0.6, toluene/acetone, 2:1) was dried
under high vacuum. The crude mesylate 31 was dissolved in DMF
(20 mL) and lithium azide (0.32 g, 6.51 mmol) was added. After
1 h at 70 °C the solution was concentrated under high vacuum, and
the residue was dissolved in water (20 mL) and extracted three
times with diethyl ether. The combined organic phases were dried
with MgSO4 and concentrated under vacuum. The residue was
purified by flash chromatography (toluene/acetone, 10:1) to afford
azide 32 (0.55 g, 84%) as a colourless oil. – TLC (toluene/acetone,
2:1): Rf ϭ 0.74, [α]D ϭ 107.7 (c ϭ 2, CHCl3). – 1H NMR
(250 MHz, CDCl3): δ ϭ 2.04/2.10 (2 s, 6 H, 2 Ac), 2.19 (dddd,
J6a,6b ϭ 13.6 Hz, J6a,5 ϭ 4.1 Hz, 4J6a,2 ഠ 4J6a,4 ഠ 1 Hz, 1 H, 6a-H),
2.31 (dd, J6b,6a ϭ 13.6 Hz, J6b,5 ϭ 11.8 Hz, 1 H, 6b-H), 3.72 (s, 3
H, COOMe), 4.25 (dd, J4,3 ϭ 5.5 Hz, J4,5 ϭ 4.1 Hz, 1 H, 4-H),
5.83 (ddd, J5,6b ϭ 11.8 Hz, J5,6a ഠ J5,4 ഠ 4.1 Hz, 1 H, 5-H), 5.97
NMR (250 MHz, CDCl3): δ ϭ 2.11/2.16 (2 s, 6 H, 2 Ac), 2.43 (dd,
2
2J ഠ J6a,5 ഠ 13.0 Hz, 1 H, 6a-H), 2.67 (ddd, J ϭ 13.2 Hz, J6b,5
ϭ
4
5.3 Hz, J6b,2 ϭ 1.9 Hz, 1 H, 6b-H), 3.78 (s, 3 H, COOMe), 5.70
(dd, J5,6a ϭ 12.7 Hz, J5,6b ϭ 5.3 Hz, 1 H, 5-H), 6.16 (d, J3,2
10.2 Hz, 1 H, 3-H), 7.30 (dd, J2,3 ϭ 10.2 Hz, J2,6b ϭ 1,9 Hz, 1 H,
ϭ
4
2-H).
Methyl (1R,5R)-1,5-Di-O-acetyl-1,5-dihydroxy-3-hydroxyliminocy-
clohex-2-ene-1-carboxylate (29): To a solution of ketone 28 (0.72 g,
2.67 mmol) in dry methanol (30 mL) were added hydroxyl ammo-
nium chloride (0.28 g, 4 mmol) and pyridine (432 µL, 0.42 g,
5.34 mmol). After 2.5 h stirring at room temp. the solvent was re-
moved under vacuum and the residue was purified by flash chro-
matography (toluene/acetone, 8:1) to afford a (E/Z)-mixture of the
oxime 29 (0.76 g, quant.). – TLC (toluene/acetone, 2:1): Rf ϭ 0.6. –
1H NMR (250 MHz, CDCl3): δ ϭ 2.01/2.06/2.07/2.08 (4 s, 6 H, 4
Ac), 2.30–2.52 (m, 2 H, 6a,b-H), 3.74/3.76 (2 s, 3 H, 2 COOMe),
5.83/6.25 [2 dd, (J5,6a ϭ 9.9 Hz, J5,6b ϭ 4.7 Hz)/(J5,6a ϾϾ J5,6b ϾϾ
5.1 Hz), 1 H, 5-H], 6.37/7.00 (2 d, J3,2 ϭ 10.3 Hz, 1 H, 3-H), 6.51/
6.60 (2 d, J2,3 ϭ 10.2 Hz, 1 H, 2-H). – MS (MALDI, positive mode,
matrix: DHB): m/z: 307 [M ϩ Na]ϩ, 441 [M ϩ DHB ϩ H]ϩ, 285.1
for C12H15NO7.
(dd, J3,2 ϭ 9.9 Hz, J3,4 ϭ 5.5 Hz, 1 H, 3-H), 6.34 (ddd, J2,3
9.9 Hz, J2,6 ϾϾ J2,4 ϾϾ 1 Hz, 1 H, 2-H). – C12H15N3O6 (297.3)
ϭ
4
4
Methyl (1R,4S,5R)-4-Acetamido-1,5-di-O-acetyl-1,5-dihydroxycy-
clohex-2-ene-1-carboxylate (30):
calcd. C 48.49, H 5.09, N 14.13; found C 48.53, H 5.27, N 13.98.
(1R,4S,5R)-4-N-Acetyl-4-amino-1,5-dihydroxycyclohex-2-ene-1-
carboxylic Acid 1,4-Lactam (34) and Methyl (1R,4S,5R)-4-Acetam-
ido-5-O-acetyl-1,5-dihydroxycyclohex-2-ene-1-carboxylate (35): To a
solution of compound 30 (320 mg, 1.03 mmol) in dry methanol
(15 mL) was added a solution of sodium methoxide in dry meth-
anol (0.5 , 1.5 mL). After 1 h stirring at room temp. the solution
was neutralised with Amberlite IR 120 (Hϩ) and concentrated un-
der vacuum. Flash chromatography (toluene/acetone, 1:2) of the
residue afforded the deacetylated compound 33 [139 mg, 59%, Rf ϭ
0.11 (toluene/acetone, 1:1)] and the lactam 34 (60 mg, 34%). To a
solution of deacylated 33 (139 mg, 0.61 mmol) in dry ethyl acetate
(10 mL), was added acetic anhydride (72 µL, 0.76 mmol), pyridine
(49 µL, 0.61 mmol), and a catalytic amount of DMAP. After 5 h
stirring at room temp., methanol (1 mL) was added and the solv-
ents were evaporated. The residue could be purified by crystallis-
ation from toluene/acetone (1:1) to yield the selectively acetylated
compound 35 (100 mg, 62%) as a colourless solid.
a) From Oxime 29: To a solution of oxime 29 (0.44 g, 1.54 mmol)
in acetic anhydride/acetic acid (1.3:1, 30 mL), zinc powder (1.0 g)
was added gradually at 0 °C. After 48 h stirring at room temp.
the suspension was filtered, and the filtrate was coevaporated with
toluene three times. The residue was purified by flash chromato-
graphy (toluene/acetone, 5:1) to yield a mixture of compound 30
(115 mg, 24%) and methyl 4-acetamidobenzoate (50 mg, 16%).
b) From Azide 32 by Catalytic Reduction with Lindlar Catalyst: To
a solution of azide 32 (100 mg, 0.34 mmol) in methanol (5 mL) was
added Lindlar catalyst (50 mg) and the suspension was hydrogen-
ated for 45 min. Then acetic anhydride (0.5 mL) was added and the
suspension was stirred for 2 h at room temp. The suspension was
filtered over Celite and the filtrate was concentrated under vacuum.
The residue was purified by flash chromatography (toluene/acet-
one, 2:1) to yield the acetamide 30 (50 mg, 47%) as a lightly yel-
low foam.
34: TLC (toluene/acetone, 1:2): Rf ϭ 0.48, [α]D ϭ –235.4 (c ϭ 0.5,
methanol). – 1H NMR (250 MHz, [D4]methanol): δ ϭ 1.99 (s, 3
H, N-Ac), 2.39 (d, J6a,6b ϭ 11.1 Hz, 1 H, 6a-H), 2.58 (ddd, J6b,6a ϭ
11.1 Hz, 4J6b,5 ϭ 6.2 Hz, 4J6b,2 ഠ 2.2 Hz, 1 H, 6b-H), 4.80–4.88 (m,
2 H, 4-, 5-H), 5.58 (ddd, J3,2 ϭ 9.8 Hz, J3,4 ഠ 4J3,5 ഠ 2.5 Hz, 1 H,
3-H), 6.10 (ddd, J2,3 ϭ 9.8 Hz, J2,6a ഠ J2,4 ഠ 2.2 Hz, 1 H, 2-H). –
MS (MALDI, positive mode, matrix: DHB): m/z: 199 [M ϩ H]ϩ,
200 [M ϩ Na]ϩ. – C9H11NO4 1/8 H2O (197.19) calcd. C 54.20, H
5.69, N 7.0; found C 54.10, H 5.90, N 6.60.
c) From Azide 32 by Reduction with Dithiothreitol (DTT): To a solu-
tion of azide 32 (370 mg, 1.25 mmol) in pyridine/water (4:1, 15 mL)
were added triethylamine (0.5 mL) and DTT (563 mg, 3.54 mmol).
After 1 h stirring at room temp. the solvents were removed under
vacuum and the residue was coevaporated three times with toluene.
The residue was dissolved in dry pyridine/acetic anhydride (2:1,
6 mL) and stirred for 15 h at room temp. After coevaporating three
times with toluene the residue was purified by flash chromato-
graphy (toluene/acetone, 2:1) to afford acetamide 30 (340 mg, 87%)
as a colourless foam. – TLC (toluene/acetone, 2:1): Rf ϭ 0.2, [α]D ϭ 35: TLC (toluene/acetone, 1:1): Rf ϭ 0.3, [α]D ϭ 59.0 (c ϭ 0.5,
1
34.3 (c ϭ 2, CH2Cl2). – 1H NMR (250 MHz, CDCl3): δ ϭ 2.05/ methanol). – H NMR (250 MHz, CDCl3): δ ϭ 1.94 (dd, J6a.6b
ϭ
1754 Eur. J. Org. Chem. 2000, 1745Ϫ1758

Sialyltransferase Inhibitors Based on CMP-Quinic Acid
FULL PAPER
13.6 Hz, J6a,5 ϭ 3.5 Hz, 1 H, 6a-H), 1.99/2.00 (2 s, 6 H, 2 Ac), 2.36
(dd, J6b,6a ϭ 13.6 Hz, J6b,5 ϭ 11.1 Hz, 1 H, 6b-H), 3.80 (s, 3 H,
COOMe), 4.87 (ddd, J4,5 ഠ J4,3 ഠ 4.6 Hz, J4,NH ϭ 8.9 Hz, 1 H, 4-
Phosphate 2: To a solution of the triethylammonium salt of com-
pound 38 (37 mg, 0.046 mmol) in dry methanol (3 mL) was added
a solution of sodium methoxide in dry methanol (0.5 , 0.3 mL).
H), 5.27 (ddd, J5,6b ϭ 11.1 Hz, J5,4 ϭ 4.5 Hz, J5,6a ϭ 3.5 Hz, 1 H, After 1 h the solution was neutralised with Amberlite IRC 176
5-H), 5.43 (br. d, JNH,4 ϭ8.9 Hz, 1 H, NH), 5.79 (d, J2,3 ϭ 9.9 Hz,
(Hϩ) and evaporated. The residue was dissolved in methanol/water
1 H, 2-H), 5.89 (dd, J3,2 ϭ 9.9 Hz, J3,4 ϭ 4.8 Hz, 1 H, 3-H). – MS (1:1, 3 mL), and NaOH (1 , 0.5 mL) was added. After stirring
(MALDI, positive mode, matrix: DHB): m/z: 272 [M ϩ H]ϩ, 295 overnight the solution was neutralised with IRC 176 (Hϩ), the pH
[M ϩ Na]ϩ, 311 [M ϩ K]ϩ. – C12H17NO6 0.5 H2O (271.27) calcd. value was adjusted to 8 with NaOH, and the solvents were removed
C 51.43, H 6.47, N 5.00; found C 51.68, H 6.15, N 5.00.
by lyophilisation. The residue was purified by precipitation from
water with ethanol and acetone to afford the disodium salt 2
(18 mg, 69%) as a colourless powder. – TLC (ethyl acetate/meth-
anol/1  NH4CH3CO2 1:1:1): Rf ϭ 0.56, [α]D ϭ 33.0 (c ϭ 0.5,
Phosphane 36: To a solution of the alcohol 35 (70 mg, 0.25 mmol)
in dry acetonitrile (7 mL), diisopropylethylamine (137 µL,
0.8 mmol) and (benzyloxy)chloro(diisopropylamino)phosphane[19]
(199 mg, 0.73 mmol) were added. The solvents were removed under
vacuum after 2.5 h stirring at room temp., and the residue was puri-
fied by flash chromatography (toluene/acetone, 5:1) to yield the
phosphitamide 36 (120 mg) contaminated with the chlorophos-
phane. – TLC (toluene/acetone, 2:1): Rf ϭ 0.38 (mixture of diaster-
1
H2O). – H NMR (600 MHz, D2O): δ ϭ 1.91 (s, 3 H, N-Ac), 1.94
(ddd, J6aЈЈ,6bЈЈ ϭ 13.8 Hz, J6aЈЈ,5ЈЈ ϭ 10.4 Hz, J ϭ 3.2 Hz, 1 H, 6aЈЈ-
H), 2.13 (dd, J6bЈ,6aЈЈ ϭ 13.8 Hz, J6bЈЈ,5ЈЈ ϭ 3.3 Hz, 1 H, 6bЈЈ-H),
3.98–4.01 (m 1 H, 5aЈ-H), 4.05–4.09 (m, 1 H, 5bЈ-H), 4.10–4.15 (m,
2 H, 4Ј-, 5ЈЈ-H), 4.17–4.22 (m, 2 H, 2Ј-, 3Ј-H), 4.47 (dd, J4ЈЈ,5ЈЈ
J4ЈЈ,3ЈЈ ഠ 4.4 Hz, 1 H, 4ЈЈ-H), 5.71 (dd, J3ЈЈ,2ЈЈ ϭ 10 Hz, J3ЈЈ,4ЈЈ
ഠ
ϭ
1
eoisomers). – H NMR (250 MHz, CDCl3): δ ϭ 1.1–1.3 [m, 12 H,
4.6 Hz, 1 H, 3ЈЈ-H), 5.88 (d, J1Ј,2Ј ϭ 4.0 Hz, 1 H, 1Ј-H), 6.01 (d,
J5,6 ϭ 7.6 Hz, 1 H, 5-H), 6.09 (d, J2ЈЈ,3ЈЈ ϭ 10.0 Hz, 1 H, 2ЈЈ-H),
7.85 (d, J6,5 ϭ 7.6 Hz, 1 H, 6-H). – 13C NMR (150.9 MHz, D2O):
2 CH(CH3)2], 1.90–2.10 (m, 1 H 6a-H), 1.96/1.97/1.98 (3 s, 6 H, 2
Ac), 2.49/2.70 (2 dd, J6b,6a ϭ 14 Hz, J6b,5 ϭ 9 Hz, 1 H, 6b-H), 3.5–
3.8 [m, 2 H, 2 CH(CH3)2], 3.65/3.66 (2 s, 3 H, COOMe), 4.5–4.7
(m, 2 H, CH2Ph), 4.82–4.94 (m, 1 H, 4-H), 5.21–5.30 (m, 1 H, 5-
H), 5.58–5.65 (m, 1 H, NH), 5.70–5.82 (m, 1 H, 3-H), 6.16/6.22 (2
dd, J2,3 ϭ10.1 Hz, J2,6a ϭ 1.7 Hz, 1 H, 2-H), 7.20–7.40 (m, 5 H, Ph).
3
δ ϭ 23.37 (Ac–CH3), 38.14 (d, JP,C ϭ 7 Hz, 6ЈЈ-C), 48.86 (4ЈЈ-C),
2
65.35 (d, JP,C ϭ 5.8 Hz, 5Ј-C), 66.53 (5ЈЈ-C), 70.66 (3Ј-C), 75.56
2
(2ЈЈ-C), 80.70 (d, JP,C ϭ 7.5 Hz, 1ЈЈ-C), 81.10 (d, JP,C ϭ 8.7 Hz,
3
4Ј-C) 90.53 (1Ј-C), 97.80 (5-C), 129.94 (3ЈЈ-C), 131.62 (2ЈЈ-C),
142.77 (6-C), 159.11 (4-C), 167.54 (2-C), 175.54 (CϭO). – 31P
NMR (161.7 MHz, D2O): d ϭ –2.91 (s, phosphate). – MS (FAB,
negative mode, H2O/glycerol): m/z: 519 [M – 2 Na ϩ H]–, 541 [M –
Na]–, 563 [M – H]–, 564.08 for C18H23N4Na2O12P.
Phosphate 37: To a solution of phosphitamide 36 (120 mg) and
cytidine 17 (144 mg, 0.39 mmol) in dry acetonitrile (3 mL), was ad-
ded tetrazole (38 mg, 0.54 mmol) under argon. After 4 h stirring at
room temp. tBuOOH (0.13 mL, 0.72 mmol, 5.5  in nonane) was
added. After 1.5 h 2–3 drops triethylamine were added and the so-
lution was concentrated under vacuum. The residue was purified
by flash chromatography (toluene/acetone, 1:1 Ǟ 1:2) to afford the
protected phosphate 37 (62 mg, 31% over 2 steps) as a colourless
oil. – TLC (toluene/acetone, 1:2): Rf ϭ 0.15 (mixture of diastereo-
isomers) – 1H NMR (250 MHz, CDCl3): δ ϭ 1.90–2.10 (m, 1 H,
6a-H), 1.94/1.96/1.98/1.99/2.05/2.06/2.25 (7 s, 15 H, 5 Ac), 2.30–
2.49 (m, 1 H, 6b-H), 3.76/3.77 (2 s, 3 H, COOMe), 4.12–4.41 (m,
3 H, 4Ј-, 5a,bЈ-H), 4.81–5.01 (m, 1 H, 4ЈЈ-H), 5.02–5.23 (m, 3 H,
CH2Ph, 5ЈЈ-H), 5.29–5.39 (m, 2 H, 2Ј-, 3Ј-H), 5.69/5.74 (2 d,
JNH,4ЈЈ ϭ 8.9 Hz, 1 H, NH), 5.90/5.99 (2 dd, J3ЈЈ,2ЈЈϭ 10.0 Hz,
J3ЈЈ,4ЈЈ ϭ 4.5, 1 H, 3ЈЈ-H), 6.05/6.14 (2 d, J1Ј,2Ј ϭ 4.0 Hz, 1 H, 1Ј-
H), 6.20–6.56 (m, 1 H, 2ЈЈ-H), 7.25–7.41 (m, 6 H, Ph, 5-H), 7.91/
8.05 (2 d, J6,5 ϭ 7.6 Hz, 1 H, 6-H).
Methyl
(3S,4R,5R)-4,5-O-Cyclohexylidene-3,4,5-trihydroxycy-
clohex-1-ene-1-carboxylate (40): Compound 40 was prepared ac-
cording to a procedure by Shing et al.[14]
Methyl (3R,4R,5R)-3-O-Benzoyl-4,5-O-cyclohexylidene-3,4,5-trihy-
droxycyclohex-1-ene-1-carboxylate (41): The alcohol 40 (10 g,
37.37 mmol), benzoic acid (8.64 g, 70.81 mmol), and triphenylphos-
phane (18.6 g, 70.81 mmol) were dried overnight in a desiccator.
The mixture was dissolved in dry THF (200 mL) and diisopropyl
azodicarboxylate (14.3 g, 70.81 mmol) in dry THF (10 mL) was ad-
ded slowly. After the lightly exothermic reaction was finished, the
solution was stirred for 2 h at room temp. and then evaporated.
The residue was purified by flash chromatography (1. toluene/ethyl
acetate 50:1 and 2. petroleum ether ether/ethyl acetate 9:1) to afford
the benzoate 41 (13 g, 94%) as a colourless solid. m.p. 91–92 °C,
TLC (toluene/ethyl acetate, 6:1): Rf ϭ 0.61, [α]D ϭ –107.4 (c ϭ 1,
Phosphate 38: To a solution of the protected phosphate 37 in meth-
anol (10 mL) was added Pd/C (10%, 10 mg). After 10 min of hydro-
genation at room temp. the catalyst was removed by filtration over
Celite, triethylamine was added, and the solvent was evaporated.
The residue was purified by flash chromatography (ethyl acetate/
methanol 3:1 ϩ 1% NEt3) to yield compound 38 (51 mg, 84%) as
a colourless lyophilisate. – TLC (ethyl acetate/methanol 3:1 ϩ 1%
NEt3 ): Rf ϭ 0.12, [α]D ϭ 52.9 (c ϭ 1, methanol). – 1H NMR
1
CHCl3). – H NMR (250 MHz, CDCl3): δ ϭ 1.30–1.70 (m, 10 H,
cyclohexylidene), 2.57–2.68 (m, 1 H, 6a-H), 2.94 (dd, 2J ϭ 17.2 Hz,
J6b,5 ϭ 6.0 Hz, 1 H, 6b-H), 3.74 (s, 3 H, COOMe), 4.39 (dd, J4,5 ϭ
6.7 Hz, J4,3 ϭ 4.7 Hz, 1 H, 4-H), 4.53 (ddd, J5,4 ഠ J5,6b ഠ 6.4 Hz,
J5,6a ϭ 4.2 Hz, 5-H), 5.58–5.60 (m, 1 H, 3-H), 6.96–6.99 (m, 1 H,
2-H), 7.38–7.45 (m, 2 H, Ph), 7.52–7.60 (m, 1 H, Ph), 8.00–8.05
(m, 2 H, Ph). – C21H24O6 (372.4) calcd.: C 67.73, H 6.50; found:
C 67.97, H 6.45.
(250 MHz, [D4]methanol):
δ ϭ 1.30 (t, J ϭ 7.3 Hz, 9 H,
NCH2CH3), 1.93/1.94/2.06/2.10/2.18 (5 s, 15 H, 5 Ac), 2.10–2.42 Methyl (3R,4R,5R)-3-O-Benzoyl-3,4,5-trihydroxycyclohex-1-ene-1-
(m, 2 H, 6a,bЈЈ-H), 3.20 (q, J ϭ 7.3 Hz, 6 H, NCH2CH3), 3.77 (s, carboxylate (42): Compound 41 (12.7 g, 34 mmol) was dissolved in
3 H, COOMe), 4.06–4.25 (m, 2 H, 5a,bЈ-H), 4.39 (m, 1 H, 4Ј-H),
acetic acid (90%, 150 mL) and stirred 3 h at 60–70 °C. The acetic
4.75–4.80 (m, 1 H, 4ЈЈ-H), 5.22–5.30 (m, 1 H, 5ЈЈ-H), 5.43–5.50 (m, acid was removed under vacuum, and the residue was twice coevap-
2 H, 2Ј-, 3Ј-H), 5.82 (dd, J3ЈЈ,2ЈЈ ϭ 10.1 Hz, J3ЈЈ,4ЈЈ ϭ 4.5 Hz, 1 H, orated with ethanol. The resulting yellow oil was purified by flash
3ЈЈ-H), 6.18 (d, J1Ј,2Јϭ 4.3 Hz, 1 H, 1Ј-H), 6.39 (d, J2ЈЈ,3ЈЈ ϭ 10 Hz, chromatography (toluene/acetone, 4:1) to yield the diol 42 (9.32 g,
1 H, 2ЈЈ-H), 7.52 (d, J5,6 ϭ7.6 Hz, 1 H, 5-H), 8.43 (d, J6,5 ϭ 7.6 Hz,
94%) as a colourless oil which solidifies on standing. m.p. 84–85
1 H, 6-H). – 31P NMR (161.7 MHz, [D4]methanol): δ ϭ –2.81 (s, °C, TLC (toluene/acetone, 4:1): Rf ϭ 0.2, [α]D ϭ –118.3 (c ϭ 2,
phosphate). – MS (MALDI, negative mode, matrix: ATT): m/z:
CHCl3) – 1H NMR (250 MHz, CDCl3): δ ϭ 2.54–2.75 (m, 2 H,
6a,b-H), 2.90 (br. s, 2 H, OH), 3.74 (s, 3 H, COOMe), 3.96 (dd,
701 [M – NHEt3]–, 803.76 for C33H50N5O16P.
Eur. J. Org. Chem. 2000, 1745Ϫ1758
1755

C. Schaub, B. Müller, R. R. Schmidt
FULL PAPER
J4,3 ϭ 7.0 Hz, J4,5 ϭ 2.5 Hz, 1 H, 4-H), 4.24 (ddd, J5,6a ഠJ5,6b
ഠ
HCl (1 ), sodium bicarbonate, and brine. After drying with
4.0 Hz, J5,4 ϭ 2.5 Hz,1 H, 5-H), 5.75–5.82 (m, 1 H, 3-H), 6.78–
MgSO4 the solvents were removed under vacuum and the residue
6.81 (m, 1 H, 2-H), 7.39–7.45 (m, 2 H, Ph), 7.52–7.60 (m, 1 H, Ph), was purified by flash chromatography (toluene/acetone, 6:1) to
8.00–8.05 (m, 2 H, Ph). – C15H16O6 (292.3) calcd.: C 61.64, H 5.5; yield the aldehyde 45 (33 mg, 45%) [besides some re-isolated start-
found: C 61.95, H 5.49.
ing material (23 mg, 25%)]. m.p. 93–94 °C, TLC (toluene/acetone,
4:1): Rf ϭ 0.55, [α]D ϭ –76.5 (c ϭ 1, CH2Cl2). – 1H NMR
(250 MHz, CDCl3): δ ϭ 2.03/2.04/2.10 (3 s, 9 H, 3 Ac), 2.50–2.70
(m, 2 H, 6a,b-H), 5.17 (dd, J4,3 ϭ 7.3 Hz, J4,5 ϭ 2.4 Hz, 1 H, 4-
H), 5.43 (ddd, J5,6a ഠ J5,6b ഠ 4.5 Hz, J5,4 ϭ 2.4 Hz, 1 H, 5-H),
5.68–5.74 (m, 1 H, 3-H), 6.58–6.61 (m, 1 H, 2-H), 9.51 (s, 1 H,
CHO). – C13H16O7 (284.3) calcd.: C 54.93, H 5.67; found: C 54.97,
H 5.66.
(3R,4R,5R)-3,4,5-Tri-O-acetyl-3,4,5-trihydroxycyclohex-1-ene-1-
carboxylate (43): To a solution of diol 42 (1.73 g, 5.93 mmol) in
methanol (50 mL) was added NaOH (1 , 5 mL). After 2 d stirring
a room temp. the solution was neutralised and converted into the
free acid with Amberlite IR 120 (Hϩ). The solvents were evapor-
ated and the residue was dissolved in pyridine/acetic anhydride (2:1,
15 mL). After 5 h stirring the solution was concentrated under va-
cuum, the residue was dissolved in ethyl acetate and washed twice
with HCl (1 ) and brine. The organic phase was dried with
MgSO4, evaporated, and the residue purified by flash chromato-
graphy (toluene/acetone, 8:1 ϩ 0.5% AcOH) to afford the free acid
43 (1.47 g, 83%) as a colourless, gluey foam. – TLC (toluene/acet-
one, 6:1ϩ 0.5% AcOH): Rf ϭ 0.31, [α]D ϭ –155.0 (c ϭ 1.25,
Phosphonate (S)-46: To a solution of aldehyde 45 (120 mg,
0.42 mmol) in dry dichloromethane (3 mL) was added diallyl phos-
phite[24] (89 mg, 0.55 mmol) and triethylamine (18 µL, 0.13 mmol).
After stirring overnight the solvent was evaporated and the residue
was purified by flash chromatography to afford the hydroxyphos-
phonate (170 mg, 91%) as a colourless oil. The two diastereoiso-
mers could be separated by repeating MPLC (toluene/ethyl acetate
1:7), whereas pure (R)-46 was first eluted followed by (S)-46 which
was obtained in 90% purity.
1
CH2Cl2). – H NMR (250 MHz, CDCl3): δ ϭ 2.03/2.05/2.08 (3 s,
9 H, 3 Ac), 2.53–2.77 (m, 2 H, 6a,b-H), 5.13 (dd, J4,3 ϭ 7.4 Hz,
J4,5 ϭ 2.4 Hz, 1 H, 4-H), 5.41 (ddd, J5,6a ഠ J5,6b ഠ 4.4 Hz, J5,4
ϭ
2.4 Hz, 1 H, 5-H), 5.63–5.68 (m, 1 H, 3-H), 6.82–6.84 (m, 1 H, 2-
H), 9.65 (br. s, 1 H, COOH). – C13H16O8 (300.3) calcd.: C 52.00,
H 5.37; found: C 52.61, H 5.78.
(R)-46: TLC (toluene/acetone, 2:1): Rf ϭ 0.19, [α]D ϭ –107 (c ϭ
0.5, CH2Cl2). – 1H NMR (250 MHz, [D4]methanol): δ ϭ 2.02/2.03/
2.06 (3 s, 9 H, 3 Ac), 2.45–2.55 (m, 1 H, 6a-H), 2.65–2.80 (m, 1 H,
6b-H), 4.53 (d, J1Ј,P ϭ 14.7 Hz, 1 H, 1Ј-H), 4.57–4.65 (m, 4 H, 2
CH2CHϭCH2), 5.16 (dd, J4,3 ϭ 6.4 Hz, J4,5 ϭ 2.4 Hz, 1 H, 4-H),
5.21–5.36 (m, 4 H, 2 CH2CHϭCH2), 5.40–5.50 (m, 2 H, 3-, 5-H),
5.81–5.89 (m, 1 H, 2-H), 5.90–6.07 (m, 2 H, 2 CH2CHϭCH2). –
31P NMR (161.7 MHz, [D4]methanol): δ ϭ 22.22 (s, phosphonate).
(3R,4R,5R)-3,4,5-Tri-O-acetyl-3,4,5-trihydroxy-N-methoxy-N-
methylcyclohex-1-ene-1-carboxamide (44): The solution of acid 43
(300 mg, 0.99 mmol) in dry dichloromethane (20 mL) was cooled
to –20 °C. N-methylpiperidine (140 µL, 1.15 mmol) was added, and
then ethyl chloroformate (106 µL, 1.1 mmol) was dropped in slowly.
After 10 min stirring at –20 °C a solution of N,O-dimethylhy-
droxylamine hydrochloride (107 mg, 1.1 mmol) and N-methylpiper-
idine (140 µL, 1.15 mmol) in dry dichloromethane (15 mL) was
dropped in slowly and stirred for 1 h. After warming to room temp.
the solution was stirred for 2 h and then was again cooled to –
20 °C. N-methylpiperidine (64 µL, 0.52 mmol) followed by ethyl
chloroformate (64 µL, 0.5 mmol) were added slowly. After 10 min
a solution of N,O-dimethylhydroxylamine hydrochloride (49 mg,
0.5 mmol) and N-methylpiperidine (64 µL, 0.52 mmol) in dry
dichloromethane (5 mL) was added, and the solution was stirred
for 30 min at –20 °C. After warming to room temp. the solution
was stirred until total conversion of the starting material. Water
was then added, the phases were separated, and the organic phase
washed twice with HCl (0.1 ) and once with sodium bicarbonate.
The organic phases were dried with MgSO4, evaporated, and the
residue was purified by flash chromatography (toluene/acetone, 6:1)
to afford the Weinreb amide 44 (250 mg, 73%) as colourless oil. –
TLC (toluene/acetone, 6:1): Rf ϭ 0.16, [α]D ϭ –115.0 (c ϭ 2,
(S)-46: TLC (toluene/acetone, 2:1): Rf ϭ 0.19, [α]D ϭ –117.2 (c ϭ
0.5, CH2Cl2). – 1H NMR (250 MHz, [D4]methanol): δ ϭ 2.03/2.04/
2.05 (3 s, 9 H, 3 Ac), 2.50–2.70 (m, 2 H, 6a,b-H), 4.50 (d, J1Ј,P
ϭ
15.0 Hz, 1 H, 1Ј-H), 4.53–4.66 (m, 4 H, 2 CH2CHϭCH2), 5.14 (dd,
J4,3 ϭ 6.6 Hz, J4,5 ϭ 2.4 Hz, 1 H, 4-H), 5.20–5.36 (m, 4 H, 2
CH2CHϭCH2 ), 5.39–5.42 (m, 1 H, 5-H), 5.43–5.57 (m, 1 H, 3-H),
5.80–5.88 (m, 1 H, 2-H), 5.90–6.06 (m, 2 H, 2 CH2CHϭCH2). –
31P NMR (161.7 MHz, [D4]methanol): δ ϭ 22.14 (s, phosphonate).
For the mass spectra and the elemental analysis a mixture of the
diastereoisomers was used: MS (MALDI, positive mode, matrix:
DHB): m/z: 470 [M ϩ Na]ϩ, C19H27O10P (446.4) calcd.: C 51.12,
H 6.10; found: C 51.20, H 6.26.
Phosphate (R)-48: Compound (R)-46 (30 mg, 67 µmol) and cytidine
phosphitamide 47 (46 mg, 81 µmol) were coevaporated with dry
dichloromethane and dried under high vacuum. The mixture was
dissolved in a small amount of dry dichloromethane, and tetrazole
(7 mg, 100 µmol) was added. After 3 h stirring at room temp. the
coupling reaction was complete and tBuOOH (25 µL, 134 µmol
5.5  in nonane) was added. After 1 h triethylamine (1 mL) was
added, and the solution stirred overnight. Evaporation of the solv-
ents and purification by flash chromatography (ethyl acetate/meth-
anol 5:1 ϩ 1% NEt3) afforded the triethylammonium salt (R)-48
(60 mg, 91%) as a colourless lyophilisate. – TLC (ethyl acetate/
methanol 3:1 ϩ 1% NEt3): Rf ϭ 0.18, [α]D ϭ –12.6 (c ϭ 0.5, meth-
anol). – 1H NMR (250 MHz, [D4]methanol): δ ϭ 1.30 (t, J ϭ
7.3 Hz, 9 H, NCH2CH3), 2.00/2.01/2.02/2.07/2.09/2.17 (6 s, 18 H,
6 Ac), 2.58–2.88 (m, 2 H, 6a,bЈЈ-H), 3.20 (q, J ϭ 7.3 Hz, 6 H,
1
CH2Cl2). – H NMR (250 MHz, CDCl3): δ ϭ 2.03/2.04/2.05 (3 s,
9 H, 3 Ac), 2.52–2.63 (m, 1 H, 6a-H), 2.71–2.82 (m, 1 H, 6b-H),
3.20 (s, 3 H, NMe), 3.62 (s, 3 H, OMe), 5.15 (dd, J4,3 ϭ 6.9 Hz,
J4,5 ϭ 2.4 Hz, 1 H, 4-H), 5.39 (ddd, J5,6a ഠ J5,6b ഠ 4.8 Hz, J5,4
ϭ
2.4 Hz, 1 H, 5-H), 5.53–5.60 (m, 1 H, 3-H), 6.01–6.05 (m, 1 H, 2-
H). – C15H21NO8 (343.3) calcd.: C 52.48, H 6.16, N 4.08; found:
C 52.98, H 6.51, N 3.89.
(3R,4R,5R)-3,4,5-Tri-O-acetyl-3,4,5-trihydroxycyclohex-1-ene-1-
carbaldehyde (45): To a solution of amide 44 (90 mg, 0.26 mmol)
in dry toluene (10 mL) and dry THF (4 mL) was added RedAl
at –60 °C (0.12 mL, 0.39 mmol, 3.4  in toluene) under an argon
atmosphere. After 30 min at –60 °C the reaction was quenched with
potassium sodium tartrate (15 mL) and warmed to room temp. The
phases were separated and the aqueous phase was extracted once
with ethyl acetate. The combined organic phases were washed with
NCH2CH3), 4.08–4.27 (m, 2 H, 5a,bЈ-H), 4.38–4.41 (m, 1 H, 4Ј-
2
H), 4.60–4.71 (m, 4 H, 2 CH2CHϭCH2), 5.08 (dd, J1ЈЈЈ,P
ϭ
15.4 Hz, 3J1ЈЈЈ,P ϭ 10.7 Hz, 1 H, 1ЈЈЈ-H), 5.17 (dd, J4ЈЈ,3ЈЈ ϭ 6.7 Hz,
J4ЈЈ,5ЈЈ ϭ 2.4 Hz, 1 H, 4ЈЈ-H), 5.21–5.53 (m, 8 H, 2Ј-,3Ј-,3ЈЈ,-5ЈЈ-H,
2 CH2CHϭCH2), 5.80–5.90 (m, 1 H, 2ЈЈ-H), 5.91–6.07 (m, 2 H, 2
1756
Eur. J. Org. Chem. 2000, 1745Ϫ1758

Sialyltransferase Inhibitors Based on CMP-Quinic Acid
FULL PAPER
CH2CHϭCH2), 6.19 (d, J1Ј.,2Ј ϭ 4.1 Hz, 1 H, 1Ј-H), 7.53 (d, J5,6 ϭ
7.6 Hz, 1 H, 5-H), 8.42 (d, J6,5 ϭ 7.6 Hz, 1 H, 6-H). – 31P NMR
1:1:0.5): Rf ϭ 0.1, [α]D ϭ –28.4 (c ϭ 0.66, H2O). – 1H NMR
(250 MHz, D2O): δ ϭ 2.18–2.32 (m, 1 H, 6aЈЈ-H), 2.33–2.48 (m, 1
(161.7 MHz, [D4]methanol): δ ϭ –0.60 (d, JP,P ϭ 33.4 Hz, phos- H, 6bЈЈ-H), 3.54 (dd, J4ЈЈ,3ЈЈ ϭ 6.1 Hz, J4ЈЈ,5ЈЈ ϭ 2.4 Hz, 1 H 4ЈЈ-H),
phate), 19.25 (d, JP,P ϭ 33.4 Hz, phosphonate). – MS (MALDI,
3.88–4.17 (m, 7 H, 2Ј-,3Ј-,4Ј-,5a,bЈ-,3ЈЈ-,5ЈЈ-H), 4.38 (dd, J1ЈЈЈ,P
14.3 Hz, J1ЈЈЈ,P ϭ 9.7 Hz, 1 H, 1ЈЈЈ-H), 5.54 (m, 1 H, 2ЈЈ-H), 5.78
ϭ
negative mode, matrix: ATT): m/z: 837 [M – NHEt3–AllylϩH]–,
877 [M – NHEt3]–. – C40H60N4O20P2 1.5 H2O (978.9) calcd.: C (d J1Ј,2Ј ϭ 4.0 Hz, 1 H, 1Ј-H), 5.92 (d, J5,6 ϭ 7.6 Hz, 1 H, 5-H),
47.77, H 6.31, N 5.57; found: C 47.83, H 6.64, N 5.23.
7.77 (d, J6,5 ϭ 7.6 Hz, 1 H, 6-H). – 31P NMR (161.7 MHz, D2O):
δ ϭ 1.02 (d, JP,P ϭ 31 Hz, phosphate), 13.55 (d, JP,P ϭ 31 Hz,
phosphonate). – MS (MALDI, negative mode, matrix: ATT): m/z:
545 [M – 3 Na ϩ 2 H]–, 611.0 for C16H22N3Na3O14P2.
Phosphate (S)-48: As described for compound (R)-48, the hydroxy-
phosphonate (S)-46 (47 mg, 0.105 mmol) was coupled with cytidine
phosphitamide 47 (72 mg, 0.126 mmol) by tetrazole activation
(11 mg, 0.138 mmol). After oxidation with tBuOOH (38 µL, Phosphate (E)-4: To a solution of compound (R,S)-48 (100 mg,
0.21 mmol 5.5  in nonane) and deprotection of the cyanoethyl
group with triethylamine, (S)-48 (89 mg, 87%) was obtained as a
0.1 mmol) in dry THF (3 mL) was added DBU (90 µL, 0.6 mmol)
and the solution was heated to 60–70 °C overnight. After cooling
colourless lyophilisate. – TLC (ethyl acetate/methanol 3:1 ϩ 1% to room temp. pyridine/acetic anhydride (1.5:1, 1.5 mL) and dry
1
NEt3): Rf ϭ 0.18, [α]D ϭ –36.1 (c ϭ 0.96, methanol). – H NMR
(250 MHz, [D4]methanol): 1.31 (t, 7.3 Hz, H,
THF (3 mL) were added and the solution was stirred for 3 h. The
solvents were removed under vacuum and residue was purified by
flash chromatography (ethyl acetate/methanol, 6:1 ϩ 1% NEt3 Ǟ
2:1 ϩ 1% NEt3) to yield the eliminated compound (90 mg) contam-
δ
ϭ
J
ϭ
9
NCH2CH3), 2.01/2.03/2.06/2.11/2.17 (5 s, 18 H, 6 Ac), 2.60–2.80
(m, 2 H, 6a,bЈЈ-H), 3.20 (q, J ϭ 7.3 Hz, 6 H, NCH2CH3), 4.08
2
(ddd, J ϭ 11.6 Hz, J5aЈ,P ϭ 4.5 Hz, J5aЈ,4Ј ϭ 2.7 Hz, 1 H, 5aЈ-H), inated with large amounts of acetate as a brown oil (Rf ϭ 0.2 (ethyl
4.23 (ddd, 2J ϭ 11.6 Hz, J5bЈ,P ϭ 5.0 Hz, J5bЈ,4Ј ϭ 2.5 Hz, 1 H, 5bЈ-
acetate/methanol, 1:1 ϩ 1% NEt3), MS (MALDI, negative mode,
H), 4.36–4.40 (m, 1 H, 4Ј-H), 4.62–4.70 (m, 4 H, 2 CH2CHϭCH2), matrix: ATT): m/z: 776 [M – NHEt3 – Allyl]–, 835 [M – NHEt3 ϩ
2
3
5.01 (dd, J1ЈЈЈ,P ϭ 15.0 Hz, J1ЈЈЈ,P ϭ 11.2 Hz, 1 H, 1ЈЈЈ-H), 5.14
(dd, J4ЈЈ.3ЈЈ ϭ 7.0 Hz, J4ЈЈ,5ЈЈ ϭ 2.4 Hz, 1 H, 4ЈЈ-H), 5.21–5.60 (m, 8 45 mg) and dimedone (70 mg, 0.5 mmol) were dissolved in dry
H, 2Ј-,3Ј-,3ЈЈ,-5ЈЈ-H, 2 CH2CHϭCH2), 5.90–6.06 (m, 3 H, 2ЈЈ-H, 2 THF (2 mL) and Pd(PPh3)4 (6 mg, 0.005 mmol) added in the dark.
CH2CHϭCH2), 6.22 (d, J1Ј.,2Ј ϭ 4.8 Hz, 1 H, 1Ј-H), 7.52 (d, J5,6 ϭ During the next 6 h, Pd(PPh3)4 (5 mg) was added twice and the
H2O]–, 918.31 for C38H56N4O18P2). Half of the brown oil (ഠ
7.6 Hz, 1 H, 5-H), 8.41 (d, J6,5 ϭ 7.6 Hz, 1 H, 6-H). – 31P NMR
(161.7 MHz, [D4]methanol ): δ ϭ –0.90 (d, JP,P ϭ 30 Hz, phos-
phate), 19.08 (d, JP,P ϭ 30 Hz, phosphonate). MS (MALDI, nega-
tive mode, matrix: ATT): m/z: 837 [M – NHEt3 – Allyl ϩ H]–, 877
[M – NHEt3]–, 978.9 for C40H60N4O20P2.
solution was stirred overnight in the dark. Triethylamine was added
and the solvent was removed under vacuum. The dimedone was
separated by RP-18 chromatography (ethanol/water 1:3) and the
residue was dissolved in aqueous ammonia (25%, 3 mL). After stir-
ring overnight the solution was evaporated and the residue was
purified by preparative HPLC (0.05  TEAB ϩ 0.5% CH3CN,
flow: 10 mL/min). The compound was converted into the sodium
salt by IR 120 (Naϩ) and lyophilised to yield the trisodium salt
(E)-4 (10 mg, 34%) as a colourless powder. – HPLC (präp RP18,
Phosphate (R)-3: To a solution of compound (R)-48 (40 mg, 41
µmol) and dimedone (57 mg, 419 µmol) in dry THF (1 mL) was
added Pd(PPh3)4 (5 mg, 4.1 µmol) in the dark. In the next 4 h,
Pd(PPh3)4 (5 mg) was added twice, then triethylamine was added
and the solvent removed under vacuum. The dimedone was re-
moved by RP-18 chromatography (ethanol/water, 1:3) and the res-
idue was dissolved in aqueous ammonia (25%, 3 mL) and stirred
overnight. The solution was evaporated under vacuum and the res-
idue was converted into the sodium salt with Amberlite IR 120
(Naϩ) and lyophilised from water. The residue was purified by pre-
cipitation form water with ethanol/acetone to yield the pure trisod-
ium salt (R)-3 (22 mg, 88%) as a colourless powder. – TLC (ethyl
acetate/methanol/1  CH3CO2NH4 1:1:0.5): Rf ϭ 0.1, [α]D ϭ 13.2
1
0.05  TEAB ϩ 0.5% CH3CN, 10 mL/min): tR ϭ 18.9 min. – H
NMR (250 MHz, D2O): δ ϭ 2.64–2.68 (m, 2 H, 6a,bЈЈ-H), 3.74–
3.82 (m, 1 H, 5ЈЈ-H), 4.03–4.19 (m, 6 H, 2Ј-,3Ј-,4Ј-,5a,bЈ-,4ЈЈ-H),
5.60–5.70 (m, 1 H, 3ЈЈ-H), 5.75 (d, J1Ј,2Ј ϭ 3.7 Hz, 1 H, 1Ј-H), 5.91
(d, J5,6 ϭ 7.6 Hz, 1 H, 5-H), 6.56 (d, J2ЈЈ,3ЈЈ ϭ 10.1 Hz, 1 H, 2ЈЈ-
H), 7.77 (d, J6,5 ϭ 7.6 Hz, 1 H, 6-H). – 13C NMR (150.9 MHz,
D2O): δ ϭ 29.97 (6ЈЈ-C), 65.54 (5Ј-C), 67.61 (4ЈЈ-C), 68.85 (5ЈЈ-C),
69.58 (3Ј-C), 75.38 (2Ј-C), 83.51 (d, J4Ј,P ϭ 8.7 Hz, 4Ј-C), 90.47 (1Ј-
C), 97.39 (5-C), 126.68 (d, J2ЈЈ,P ϭ 11 Hz, 2ЈЈ-C), 130.52 (3ЈЈ-C),
142.41 (6-C), 158.66 (4-C), 167.18 (2-C). – 31P NMR (243 MHz,
D2O): δ ϭ –5.09 (br. s, phosphate), 2.69 (br. s, phosphonate). – MS
(MALDI, negative mode, matrix: ATT): m/z: 527 [M – 3 Na ϩ
2 H]–, 570 [M – Na]–, 592 [M – H]–, 593.01 for C16H20N3Na3O13P2.
1
(c ϭ 1, H2O). – H NMR (250 MHz, D2O): δ ϭ 2.14–2.25 (m, 1
H, 6aЈЈ-H), 2.42–2.53 (m, 1 H, 6bЈЈ-H), 3.54 (dd, J4ЈЈ,3ЈЈ ϭ 5.5 Hz,
J4ЈЈ,5ЈЈ ϭ 2.4 Hz, 1 H 4ЈЈ-H), 3.82–3.91 (m, 1 H, 5ЈЈ-H), 4.00–4.10
(m, 5 H, 2Ј-,4Ј-,5a,bЈ-,3ЈЈ-H), 4.12–4.20 (m, 1 H, 3Ј-H), 4.27 (dd,
J1ЈЈЈ,P ϭ 13.8 Hz, J1ЈЈЈ,P ϭ 9.7 Hz, 1 H, 1ЈЈЈ-H), 5.50 (m, 1 H, 2ЈЈ- Phosphonate (R,S)-50: To a solution of (R)-46 (15 mg, 33.6 mmol)
H), 5.75 (d J1Ј,2Ј ϭ 3.0 Hz, 1 H, 1Ј-H), 5.93 (d, J5,6 ϭ 7.5 Hz, 1 H, in dry pyridine (1 mL) was added, at 0 °C, (R)-49[24] (13 mL,
5-H), 7.83 (d, J6,5 ϭ 7.5 Hz, 1 H, 6-H). – 13C NMR (150.9 MHz, 67 mmol). After 2 h stirring at room temp. the reaction mixture is
D2O): d ϭ 31.45 (6ЈЈ-C), 64.47 (d, 2J5Ј,P ϭ 4.6 Hz, 5Ј-C), 68.59 (5ЈЈ-
concentrated in vacuo. Flash chromatography with toluene/acetone
C), 69.19 (3Ј-C), 70.43 (3ЈЈ-C), 74.64 (4ЈЈ-C), 75.51 (2ЈЈ-C), 79.03 (6:1) as eluent gave (R,S)-50 (18 mg, 85%) as colorless oil. – TLC
(dd, 1J1ЈЈЈ,P ϭ 149.7 Hz, 2J1ЈЈЈ,P ϭ 8.7 Hz, 1ЈЈЈ-C), 83.35 (d, 3J4ЈЈ,P ϭ (toluene/acetone, 2:1): Rf 1H NMR (250 MHz,
0.53.
8.7 Hz, 4Ј-C), 90.68 (1Ј-C), 97.35 (5-C), 123.22 (d, 3J2ЈЈ,P ϭ 8.1 Hz, [D4]MeOD): δ ϭ 2.03/2.05 (2 s, 9 H, 3 Acetyl), 2.18–2.32 (m, 1 H,
ϭ
–
2ЈЈ-C), 138.07 (1ЈЈ-C), 142.37 (6-C), 158.61 (4-C), 167.19 (2-C). –
6a-H), 2.43–2.56 (m, 1 H, 6b-H), 3.63 (d, JOMe,F ϭ 1.2 Hz, 3 H,
OMe), 4.55–4.68 (m, 4 H, 2 CH2CH ϭCH2), 5.08 (dd, J4,3 ϭ 6.4,
31P NMR (161.7 MHz, D2O): δ ϭ 1.22 (d, JP,P ϭ 31 Hz, phos-
phate), 12.71 (d, JP,P ϭ 31 Hz, phosphonate). – MS (MALDI, J4,5 ϭ 2.3 Hz, 1 H, 4-H), 5.14–5.42 (m, 6 H, 3-, 5-H, 2 CH2CHϭ
negative mode, matrix: ATT): m/z: 544 [M – 3 Na ϩ 2 H]–, 567 CH2), 5.64–5.72 (m, 1 H, 2-H), 5.87 (d, J1Ј,P 13.4 Hz, 1 H, 1Ј-H),
[M – 2 Na ϩ 1 H]–, 611.0 for C16H22N3Na3O14P2.
5.86–6.02 (m, 2 H, 2 CH2CHϭCH2), 7.43–7.53 (m, 5 H, Phenyl). –
31P NMR (161.7 MHz, [D4]MeOD): δ ϭ 16.67 (s, phosphonate).
Phosphate (S)-3: As described for (R)-3 compound, (S)-48 was con-
verted into the trisodium salt (S)-3 (22 mg, 88%), contaminated Phosphonate (S,S)-50: This compound was obtained from (S)-46
with 4% (R)-3. – TLC (ethyl acetate/methanol/1  CH3CO2NH4,
Eur. J. Org. Chem. 2000, 1745Ϫ1758
and (R)-49[24] as described above. – TLC (toluene/acetone, 2:1)
1757

C. Schaub, B. Müller, R. R. Schmidt
FULL PAPER
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5.60 (m, 1 H, 3-H), 5.69–5.91 (m, 3 H, 2-H, 2 CH2CHϭCH2), 5.73
(d, J1Ј,P ϭ 14 Hz, 1 H, 1Ј-H), 7.33–7.52 (m, 5 H, phenyl). – 31P
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Acknowledgments
This work was supported by the Deutsche Forschungsgemeinschaft
and the Fonds der Chemischen Industrie. Ϫ C.S. is grateful for a
stipend from the Fonds der Chemischen Industrie. The help of Dr.
Armin Geyer in the structural assignments is gratefully acknow-
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