Synthesis of enantiomerically pure bis(hydroxymethyl)-branched cyclohexenyl and cyclohexyl purines as potential inhibitors of HIV

Article abstract of DOI:10.1021/jo9603542

The synthesis of the enantiomerically pure bis(hydroxymethyl)-branched cyclohexenyl and cyclohexyl purines is described. Racemic trans-4,5-bis(methoxycarbonyl)cyclohexene [(±)-6] was reduced with lithium aluminum hydride to give the racemic diol (±)-7. Resolution of (±)-7 via a transesterification process using lipase from Pseudomonas sp. (SAM-II) gave both diols in enantiomerically pure form. The enantiomerically pure diol (S,S)-7 was benzoylated and epoxidized to give the epoxide 9. Treatment of the epoxide 9 with trimethylsilyl trifluoromethanesulfonate and 1,5-diazabicyclo[5.4.0]undec-5-ene followed by dilute hydrochloric acid gave (1R,4S,5R)-4,5-bis[(benzoyloxy)methyl]1-hydroxycyclohex-2-ene (10). Acetylation of 10 gave (1R,4S,5R)-1-acetoxy-4,5-bis[(benzoyloxy)methyl]cyclohex-2-ene (11). (1R,4S,5R)-1-Acetoxy-4,5-bis[(benzoyloxy)methyl]cyclohex-2-ene (11) was converted to the adenine derivative 12 and guanine derivative 13 via palladium(0)-catalyzed coupling with adenine and 2-amino-6-chloropurine, respectively. Hydrogenation of 12 and 13 gave the corresponding saturated adenine derivative 14 and guanine derivative 15. (1R,4S,5R)-4,5-Bis[)benzoyloxy)methyl]-1-hydroxycyclohex-2-ene (10) was converted to the adenine derivative 16 and guanine derivative 17 via coupling with 6-chloropurine and 2-amino-6-chloropurine, respectively, using a modified Mitsunobu procedure. Hydrogenation of 16 and 17 gave the corresponding saturated adenine derivative 18 and guanine derivative 19. Compounds 12-19 were evaluated for activity against human immunodeficiency virus (HIV), but were found to be inactive. Further biological testings are underway.

Full text of DOI:10.1021/jo9603542

6282
J . Org. Chem. 1996, 61, 6282-6288
Syn th esis of En a n tiom er ica lly P u r e Bis(h yd r oxym eth yl)-Br a n ch ed
Cycloh exen yl a n d Cycloh exyl P u r in es a s P oten tia l In h ibitor s
of HIV
A° sa Rosenquist and Ingemar Kvarnstro¨m
Department of Chemistry, Linko¨ping University, S-581 83 Linko¨ping, Sweden
Bjo¨rn Classon and Bertil Samuelsson*,†
Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University,
S-106 91 Stockholm, Sweden
Received February 21, 1996X
The synthesis of the enantiomerically pure bis(hydroxymethyl)-branched cyclohexenyl and cyclohexyl
purines is described. Racemic trans-4,5-bis(methoxycarbonyl)cyclohexene [(()-6] was reduced with
lithium aluminum hydride to give the racemic diol (()-7. Resolution of (()-7 via a transesterification
process using lipase from Pseudomonas sp. (SAM-II) gave both diols in enantiomerically pure form.
The enantiomerically pure diol (S,S)-7 was benzoylated and epoxidized to give the epoxide 9.
Treatment of the epoxide 9 with trimethylsilyl trifluoromethanesulfonate and 1,5-diazabicyclo-
[5.4.0]undec-5-ene followed by dilute hydrochloric acid gave (1R,4S,5R)-4,5-bis[(benzoyloxy)methyl]-
1-hydroxycyclohex-2-ene (10). Acetylation of 10 gave (1R,4S,5R)-1-acetoxy-4,5-bis[(benzoyloxy)-
methyl]cyclohex-2-ene (11). (1R,4S,5R)-1-Acetoxy-4,5-bis[(benzoyloxy)methyl]cyclohex-2-ene (11)
was converted to the adenine derivative 12 and guanine derivative 13 via palladium(0)-catalyzed
coupling with adenine and 2-amino-6-chloropurine, respectively. Hydrogenation of 12 and 13 gave
the correspondning saturated adenine derivative 14 and guanine derivative 15. (1R,4S,5R)-4,5-
Bis[(benzoyloxy)methyl]-1-hydroxycyclohex-2-ene (10) was converted to the adenine derivative 16
and guanine derivative 17 via coupling with 6-chloropurine and 2-amino-6-chloropurine, respectively,
using a modified Mitsunobu procedure. Hydrogenation of 16 and 17 gave the corresponding
saturated adenine derivative 18 and guanine derivative 19. Compounds 12-19 were evaluated
for activity against human immunodeficiency virus (HIV), but were found to be inactive. Further
biological testings are underway.
In tr od u ction
1 and 2. More recently a new carbocyclic nucleoside
analogue, (1R,4S,5R)-9-[4,5-bis(hydroxymethyl)cyclopent-
2-en-1-yl]-9H-adenine5 (3), was reported to show potent
anti-HIV activity in vitro. A special feature of the
During recent years nucleoside analogues have been
extensively evaluated in the search for agents effective
against the human immunodeficiency virus (HIV), the
causative agent of acquired immune deficiency syndrome
(AIDS).1 More effective treatment has also been sought
for other virus, in particular herpes simplex virus (HSV
1 and 2), varicella zoster virus (VZV), cytomegalo virus
(CMV), and Epstein-Barr virus (EBV), which can prove
lethal to AIDS patients and other immune-compromised
individuals.2 Carbocyclic nucleosides have emerged as
a particularly interesting class of nucleosides and several
derivatives with potent antiviral activity have been
discovered.3 Carbovir4 (1) and carbocyclic oxetanocin G2
(2) are two carbocyclic nucleoside analogues which were
early reported to show in vitro activity against HIV. The
carbocyclic oxetanocin G also shows activity against HSV
† Additional Address: Astra Ha¨ssle AB, S-431 83 Mo¨lndal, Sweden.
X Abstract published in Advance ACS Abstracts, August 1, 1996.
(1) J ohnston, M. I.; Hoth, D. F. Science 1993, 260, 1286.
(2) Norbeck, D. W.; Kern, E.; Hiyashi, S.; Rosenbrook, W.; Sham,
H.;Herrin, T.; Plattner, J . J .; Erickson, J .; Clement, J .; Swanson, R.;
Shipkowitz, N.; Hardy, D.; Marsh, K.; Arnett, G.; Shannon, W.; Broder,
S.; Mitsuya, H. J . J . Med. Chem. 1990, 33, 1281.
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Borthwick, A. D.; Biggadike, K. Tetrahedron 1992, 48, 571. (c)
Niitsuma, S.; Ichikawa, Y.-I.; Takita, T. Studies in Natural Product
Chemistry: Elsevier Science Publishers: New York, 1992; p 585. (d)
Agrofoglio, L.; Suhas, E.; Farese, A.; Condom, R.; Challand, S. R.; Earl,
R. A.; Guedj, R. Tetrahedron 1994, 50, 10611.
carbocyclic nucleosides is the absence of a glycosidic
linkage which increases the metabolic stability against
phosphorylase and hydrolase enzymes, which cleave the
glycosidic linkage in normal nucleosides.6,7 The com-
paratively higher lipophilicity of the carbocyclic nucleo-
(4) (a) Vince, R.; Hua, M.; Brownell, J .; Daluge, S.; Lee, F.; Shannon,
W. M.; Lavelle, G. C.; Qualls, J .; Weislow, O. S.; Kiser, R.; Canonico,
P. G.; Schultz, R. H.; Narayanan, V. L.; Mayo, J . G.; Shoemaker, R.
H; Boyd, M. R. Biochem. Biophys. Res. Commun. 1988, 156, 1046. (b)
Vince, R.; Hua, M. J . Med. Chem. 1990, 33, 17.
(5) (a) Katagiri, N.; Nomura, M.; Sato, H.; Kaneko, C.; Yusa, K.;
Tsuruo, T. J . Med. Chem. 1992, 35, 1882. (b) Katagiri, N.; Shiraishi,
T.; Sato, H.; Toyota, A.; Kaneko, C.; Yusa, K.; Oh-hora, T.; Tsuruo, T.
Biochem. Biophys. Res. Commun. 1992, 184, 154.
S0022-3263(96)00354-4 CCC: $12.00 © 1996 American Chemical Society

Purines as Potential Inhibitors of HIV
J . Org. Chem., Vol. 61, No. 18, 1996 6283
Sch em e 1
sides is potentially beneficial for increasing oral avail-
ability and cell wall penetration.
Despite the fact that the carbocyclic nucleosides have
been extensively studied, few efforts have been directed
toward the synthesis of six-membered carbocyclic nucleo-
sides.8 As a continuation of our work on the structure-
activity relationship of different types of hydroxymethyl-
branched nucleosides9 we have synthesized (1S,4S,5R)-
and (1R,4S,5R)-9-[4,5-bis(hydroxymethyl)cyclohex-2-en-
1-yl]-9H-adenine and -guanine (4a ,b ). Compounds 4a
can be viewed as a ring expanded analogue of (1R,4S,5R)-
9-[4,5-bis(hydroxymethyl)cyclopent-2-en-1-yl]-9H-ad-
enine, while compounds 4b can be viewed as analogues
of carbovir. We have also synthesized the corresponding
saturated compounds (1R,4S,5R)- and (1S,4S,5R)-9-[4,5-
bis(hydroxymethyl)cyclohexyl]-9H-adenine and -guanine
(5a ,b). These structures can be viewed as ring expanded
analogues of carbocyclic oxetanocin G.
drolases (lipases, esterases) are well known for their
capability to differentiate between enantiotopic groups
in meso substrates, as well as their capability to catalyze
the hydrolysis of esters and their synthesis by esterifi-
cation or transesterification.11,12 The transesterification
and hydrolysis of racemic trans-1,2-dihydroxy- and trans-
1,2-diacetoxy-substituted cyclic substrates catalyzed by
Pseudomonas lipases have been examined in detail.13 In
the transesterification reactions enantiomerically pure
(g98% ee) diacetates were obtained. High selectivity
were also observed in the hydrolysis reactions resulting
in monoacetates with excellent optical purity (g95% ee).
Similar results were observed when the transesterifica-
tion and hydrolysis of cis-1,2-bis(hydroxymethyl)- and cis-
1,2-bis(acetoxymethyl)-substituted cyclic substrates cata-
lyzed by lipase from Pseudomonas sp. were examined.14
Both the transesterification and the hydrolysis methodol-
ogy produced the monoacetates in high optical purity
(g85% ee). In the literature only a few examples of
Pseudomonas lipase-catalyzed transformations of racemic
trans-1,2-bis(hydroxymethyl)- and trans-1,2-bis(acetoxy-
methyl)-substituted cyclic substrates have been pre-
Resu lts a n d Discu ssion
The synthesis starts from the racemic cyclohexene
diester (()-6, which was synthesized in a Diels-Alder
reaction of 3-sulfolene and dimethyl fumarate (Scheme
1).10 Reduction of the two ester groups in (()-6 with
lithium aluminum hydride in tetrahydrofuran gave (()-7
in 93% yield. The racemic diol (()-7 was resolved via a
lipase-catalyzed transesterification process. Ester hy-
(6) (a) Shealy, Y. F.; Clayton, J . D. J . Am. Chem. Soc. 1966, 88, 3885.
(b) Shealy, Y. F.; Clayton, J . D. J . Am. Chem. Soc. 1969, 91, 3075.
(7) Shealy, Y. F. Clayton, J . D. J . Pharm. Sci. 1973, 62, 1432.
(8) (a) Schaeffer, H. J .; Weimar, R. D., J r. J . Am. Chem. Soc. 1959,
81, 197. (b) Kitagawa, I.; Cha, B. C.; Naktae, T.; Okaichi, Y.; Takinami,
Y.; Yoshikawa, M. Chem. Pharm. Bull. 1989, 37, 542. (c) Young, R.
C.; J ones, M.; Milliner, K. J .; Rana, K. K.; Ward, J . G. J . Med. Chem.
1990, 33, 2073. (d) Ramesh, K.; Wolfe, M. S.; Lee, Y.; Velde, D. V.;
Borchardt, R. T. J . Org. Chem. 1992, 57, 5861. (e) Arango, J . H.; Geer,
A.; Rodriguez, J .; Young, P. E.; Scheiner, P. Nucleosides Nucleotides
1993, 12, 773. (f) Pe´rez-Pe´rez, M.-J .; Rozenski, J .; Bussom, R.;
Herdewijn, P. J . Org. Chem. 1995, 60, 1531. (g) Konkel, M. J .; Vince,
R. Nucleosides Nucleotides 1995, 14, 2061. (h) Konkel, M. J .; Vince,
R. Tetrahedron 1996, 52, 799.
(9) (a) Svansson, L.; Kvarnstro¨m, I.; Classon, B.; Samuelsson, B. J .
Org. Chem. 1991, 56, 2993. (b) Ioannididis, P.; Classon, B.; Samuelsson,
B.; Kvarnstro¨m, I. Nucleosides Nucleotides 1992, 11, 1205. (c) J anson,
M.; Svansson, L.; Svensson, S. C. T.; Kvarnstro¨m, I.; Classon, B.;
Samuelsson, B.; Nucleosides Nucleotides 1992, 11, 1739. (d) Bjo¨rsne,
M.; Classon, B.; Kvarnstro¨m, I.; Samuelsson, B.; Tetrahedron 1993,
49, 8637. (e) Rosenquist, Å.; Kvarnstro¨m, I.; Svensson, S. C. T.; Classon,
B.; Samuelsson, B. J . Org. Chem. 1994, 59, 1779. (f) Brånalt, J .;
Kvarnstro¨m, I.; Svensson, S. C. T.; Classon, B.; Samuelsson, B. J . Org.
Chem. 1994, 59, 1783. (g) Wachtmeister, J .; Classon, B.; Samuelsson,
B.; Kvarnstro¨m, I. Tetrahedron 1995, 51, 2029.
(11) Faber, K. Biotransformations in Organic Chemistry; Springer-
Verlag: New York, 1992.
(12) Wong, G. H.; Whitesides, G. M. Enzymes in Synthetic Organic
Chemistry; Elsevier Science Ltd.: 1994.
(13) (a) Crout, D. H. G.; Gaudet, V. S. B.; Laumen, K.; Schneider,
M. P. J . Chem. Soc., Chem. Commun. 1986, 808. (b) Xie, Z.-F.;
Suemune, H.; Nakamura, I.; Sakai, K. Chem. Pharm. Bull. 1987, 35,
4454. (c) Xie, Z.-F.; Nakamura, I.; Suemune, H.; Sakai, K. J . Chem.
Soc., Chem. Commun. 1988, 966. (d) Suemune, H.; Hizuka, M.;
Kamashita, T.; Sakai, K. Chem. Pharm. Bull. 1989, 37, 1379. (e)
Seemayer, R.; Schneider, M. P. J . Chem. Soc., Chem. Commun. 1991,
49.
(10) Sample, T. E.; Hatch, L. F. Org. Synth., Coll. Vol. VI, 1988, p.
454.
(14) Ader, U.; Breitgoff, D.; Klein, P.; Laumen, K. E.; Schneider, M.
P. Tetrahedron Lett. 1989, 30, 1793.

6284 J . Org. Chem., Vol. 61, No. 18, 1996
Rosenquist et al.
Sch em e 2
Sch em e 3
F igu r e 1.
nas sp. was also studied. The hydrolysis reaction was
stereochemically complementary to the transesterifica-
tion reaction resulting in the opposite pairs of enanti-
omers. The recovered (R,R)-diacetate (R,R)-7b was
obtained in 45% ee (53% yield), the (S,S)-monacetate
(S,S)-7a in 65% ee (38% yield), and the (S,S)-diol (S,S)-7
in 62% ee (7% yield) (Scheme 2). Addition of the water-
immiscible organic cosolvents diethyl ether or toluene
gave only a minor improvement of the enantioselectivity.
In both the enzymatic transformations the functional
group with the S-configuration was preferentially re-
acted. These results are in agreement with the results
obtained in the Pseudomonas lipase-catalyzed transfor-
mations of other racemic trans-1,2-bis(hydroxymethyl)-
and trans-1,2-bis(acetoxymethyl)-substituted cyclic sub-
strates.15,16 However, compared to Pseudomonas lipase-
catalyzed reactions of racemic trans-1,2-dihydroxy- and
trans-1,2-diacetoxy-substituted cyclic substrates, in which
the functional group with the R-configuration was pref-
erentially reacted,13 these results indicates a reversal of
the enzyme enantioselectivity going from a trans-1,2-
disubstituted cyclic substrate with primary alcohol or
acetate groups to a trans-1,2-disubstituted cyclic sub-
strate with secondary alcohol or acetate groups.
sented, resulting in products with low optical purity
(e40% ee).15,16 We have examined the Pseudomonas sp.
lipase-catalyzed transformations of racemic trans-4,5-bis-
(hydroxymethyl)cyclohexene (()-7. Since the enantiose-
lectivity of the enzyme can be greatly affected by the
nature of the solvent, the effect of different organic
cosolvents on the enantioselectivity of the enzyme in both
the transesterification17 and hydrolysis18 reactions were
studied. Transesterification of (()-7 using lipase from
Pseudomonas sp. (SAM-II) and vinyl acetate in chloro-
form gave 44% of (S,S)-diacetate (S,S)-7b, 50% of (R,R)-
monoacetate (R,R)-7a , and 5% of unesterified (R,R)-diol
(R,R)-7 (75% ee). Compounds (S,S)-7b and (R,R)-7a were
deacetylated with methanolic sodium methoxide to give
(S,S)-7 (89% ee) and (R,R)-7 (63% ee), respectively
(Scheme 1). The enantiomeric purity and the absolute
stereochemistry were determined by comparison with the
optical rotation of compound (S,S)-7 reported by Heath-
cook et al.19 The enantiomeric purity was increased by
recrystallization, which gave enantiomerically pure diols
(S,S)-7 and (R,R)-7 with >99% ee, respectively. The total
yield were 36% for (S,S)-7 and 32% for (R,R)-7 from
racemic material. The addition of the cosolvent chloro-
form increased the enantioselectivity of the enzyme
compared to using only vinyl acetate both as acylation
agent and as solvent. Addition of other cosolvents such
as dioxane, nitromethane, methyl tert-butyl ether, and
toluene decreased the enantioselectivity. When dimeth-
ylformamide was used as cosolvent no reaction was
observed. No correlation between enantioselectivity and
solvent properties such as log P or dielectric constant (ꢀ)
were found. The hydrolysis of the racemic diacetate (()-
7b in phosphate buffer catalyzed by lipase from Pseudomo-
The enantiomerically pure diol (S,S)-7 was benzoylated
with benzoyl chloride in pyridine at room temperature
to give 8 in 98% yield (Scheme 3). Epoxidation of 8 with
m-chloroperbenzoic acid in methylene chloride gave the
epoxide 9 in 87% yield. The epoxide 9 was then converted
to the allylic alcohol 10. Treatment of 9 with trimeth-
ylsilyl trifluoromethanesulfonate and 1,5-diazabicyclo-
[5.4.0]undec-5-ene in toluene at room temperature gave
the corresponding allylic alcohol protected as a trimeth-
ylsilyl ether.20 The trimethylsilyl group was removed by
treatment with dilute hydrochloric acid in methanol to
give exclusively the allylic alcohol 10. The isolated yield
of 10 from 9 was 86% after column chromatography. The
configuration at C-1 in compound 10 was assigned by
1
several H NMR decoupling experiments. For H-6a two
large coupling constants, 14.3 and 10.0 Hz with H-6e and
H-5 respectively, were detected. The coupling constant
between H-6a and H-1 is a small one of 2.5 Hz. All
together these coupling constants indicates that the
hydroxyl group on C-1 occupy a pseudoaxial position
(Figure 1). Acetylation of the allylic alcohol 10 with
acetic anhydride in pyridine at room temperature gave
11 in 96% yield (Scheme 3).
Compounds 12 and 13 were synthesized via palladium-
(0)-catalyzed coupling of the allylic acetate 11 with the
anions of the purine bases.21-23 Coupling under these
(15) Suemune, H.; Tanaka, M.; Obaishi, H.; Sakai, K. Chem. Pharm.
Bull. 1988, 36, 15.
(16) Roberts, S. M.; Steukers, V. G. R.; Taylor, P. L. Tetrahedron:
Assymetry 1993, 4, 969.
(17) (a) Fitzpatrik, P. A.; Klibanov, A. M. J . Am. Chem. Soc. 1991,
113, 3166. (b) Wescott, C. R.; Klibanov, A. M. Biochem. Biophys. Acta
1994, 1206.
(18) Patel, R. N.; Robinson, R. S.; Szarka, L. J . Appl. Microbiol.
Biotechnol. 1990, 34, 10.
(20) (a) Murata, S.; Suzuki, M.; Noyori, R. J . Am. Chem. Soc. 1979,
101, 2738. (b) Murata, S.; Suzuki, M.; Noyori, R. Bull. Chem. Soc. J pn.
1982, 55, 247.
(21) Trost, B. M.; Kuo, G.-H.; Benneche, T. J . Am. Chem. Soc. 1988,
110, 621.
(19) Heathcock, C. H.; Davies, B. R.; Hadley, C. R. J . Med. Chem.
1989, 32, 197.
(22) Saville-Stones, E. A.; Lindell, S. D.; J ennings, N. S.; Head, J .
C.; Ford, M. J . J . Chem. Soc., Perkin. Trans. 1991, 2603.

Purines as Potential Inhibitors of HIV
J . Org. Chem., Vol. 61, No. 18, 1996 6285
Sch em e 4
conditions have been reported to give both five-
membered21-23 and six-membered8h carbocyclic nucleo-
sides with retention of the configuration at carbon one
(C-1) of the allylic acetate. Thus, the allylic acetate 11
was coupled with adenine in the presence of sodium
hydride and tetrakis(triphenylphosphine)palladium(0)
followed by deprotection with methanolic ammonia under
pressure to give the adenine derivative 12 in 69% yield
(Scheme 4). Coupling of the allylic acetate 11 with
2-amino-6-chloropurine, a commonly used surrogate for
the insoluble guanine base, following the same protocol
as above gave the protected 2-amino-6-chloropurine
derivative. Deprotection and hydrolytic cleavage of the
6-chloro moiety with aqueous sodium hydroxide gave the
guanine derivative 13 in 46% overall yield. Both these
coupling reactions resulted in exclusive formation of the
desired N-9 alkylated isomers, which were assigned by
NMR24 and UV25 spectroscopy. The stereoselectivity in
these palladium(0)-catalyzed coupling reactions was con-
firmed from the 1H NMR coupling constants of the
adenine derivative 12 and the guanine derivative 13
obtained from selective decoupling experiments. For
compound 12 the signal for H-6a appeared as a triplet of
doublets with coupling constants of 11.2 Hz with H-6e
and H-5 and 4.3 Hz with H-1. The signal for H-6e
appears as doublet of triplets with coupling constants of
triphenylphosphine-diisopropyl azodicarboxylate-pu-
rine complex was formed at 0 °C before it was cooled to
-78 °C and the allylic alcohol was added. The mixture
was then stirred at 0 °C for 48 h. Contrary to the
palladium(0)-catalyzed reaction, coupling under Mit-
sunobu conditions have been shown to give both five-
membered27 and six-membered8f carbocyclic nucleosides
with inversion of the configuration at carbon one (C-1)
of the allylic alcohol. Thus, coupling of the allylic alcohol
10 with 6-chloropurine and 2-amino-6-chloropurine gave
the protected 6-chloropurine and 2-amino-6-chloropurine
derivatives, respectively (Scheme 5). Subsequent treat-
ment of the 6-chloropurine derivative with methanolic
ammonia under pressure gave the adenine derivative 16
in 52% overall yield. Deprotection and hydrolytic cleav-
age of the 6-chloro moiety in the protected 2-amino-6-
chloropurine derivative with aqueous sodium hydroxide
gave the guanine derivative 17 in 34% yield from 10. The
coupling of 2-amino-6-chloropurine gave exclusively the
desired N-9 alkylated isomer, while the coupling of
6-chloropurine besides the desired N-9 alkylated isomer
also gave traces (<5%) of the N-7 alkylated isomer. The
regioselectivity of the alkylations were assigned by
NMR24 and UV25 spectroscopy. Hydrogenation of com-
pounds 16 and 17 over palladium on carbon gave the
saturated adenine derivative 18 and guanine derivative
19 in 99 and 93% yield.
11.5 Hz with H-6a and 3.3 Hz with H-5 and H-1.
A
similar pattern for both protons was observed for com-
pound 13. Altogether these coupling constants confirm
that the adenine and guanine bases, respectively, occupy
a pseudoaxial position and that the palladium(0)-
catalyzed coupling reactions thereby proceeds with reten-
tion of configuration at carbon one (C-1) of the allylic
acetate. The adenine derivative 12 and the guanine
derivative 13 were hydrogenated over palladium on
carbon to give the corresponding saturated compounds
14 and 15 in 98 and 95% yield, respectively.
The guanine derivatives 13, 15, 17, and 19 were
purified by preparative high-pressure liquid chromatog-
raphy. Comparisons of the retention times further
indicate that the coupling reactions proceeded with
complete retention and inversion, respectively.
Compounds 12-19 were tested for inhibition of HIV
multiplication in an XTT assay on M4 cells,28 and were
found to be inactive in the assay. All compounds will be
further screened for biological activity.
For the synthesis of compounds 16 and 17 a slightly
Exp er im en ta l Section
modified Mitsunobu procedure was used.9g,26,27 The
Removal of solvents was performed under reduced pressure.
1H and 13C NMR were recorded using CDCl3, MeOH-d4, or
DMSO-d6 as solvents. TLC analyses were performed on Merck
precoated 60 F-254 plates. The spots were visualized by UV
light and/or charring with ethanol/sulfuric acid/acetic acid/p-
anisaldehyde, 90:3:1:2. Column chromatography were per-
formed using silica gel 60 (0.040-0.063 mm, Merck). High-
(23) Evans, C. T.; Roberts, S. M.; Shoberu, K. A.; Sutherland, A. G.
J . Chem. Soc., Perkin. Trans. 1992, 589.
(24) (a) Chenon, M.-T.; Pugmire, R. J .; Grant, D. M.; Panzica, R. P.
; Townsend, L. B. J . Am. Chem. Soc. 1975, 97, 4627. (b) Kjellberg, J .;
J ohansson, N. G. Tetrahedron 1986, 42, 6541.
(25) Albert, A. Synthetic Procedures in Nucleic Acid Chemistry;
Wiley-Interscience: New York, 1973; Vol. 2, p 47.
(26) Mitsunobu, O. Synthesis 1981, 1.
(27) Toyota, A.; Katagiri, N.; Kaneko. C. Synth. Commun. 1993, 23,
1295.
(28) Vial, J .-M.; J ohansson, N. G.; Vrang, L.; Chattopadhyanhya,
J . Antiviral. Chem. Chemother. 1990, 1, 1983.

6286 J . Org. Chem., Vol. 61, No. 18, 1996
Rosenquist et al.
Sch em e 5
pressure liquid chromatography were performed using a
prepacked steel column (250 × 25 mm) using Polygosil 60-7,
C-18 (Macherey-Nagel). Organic phases were dried over
anhydrous magnesium sulfate. Optical rotations were mea-
sured in CHCl3 or DMSO solutions at room temperature.
Lipase from Pseudomonas sp. (SAM-II, 31.5 U/mg) was
purchased from Fluka Biochemica.
to give enantiomerically pure (R,R)-diol (R,R)-7 (1.79 g, 32%):
mp 62-63 ° C; [R]22 -76.4° (c 1.00, CHCl3). Anal. Calcd for
D
C8H14O2: C, 67.58; H, 9.92. Found: C, 67.64; H, 10.02.
(4S,5S)-4,5-Bis[(b en zoyloxy)m et h yl]cycloh exen e (8).
To a solution of compound (S,S)-7 (1.81 g, 12.7 mmol) in
pyridine (10.2 mL) was added benzoyl chloride (5.1 mL, 44.2
mmol) dropwise at 0 °C. The reaction mixture was stirred at
room temperature for 30 min and at 80 °C for 2 h before
crushed ice was added. After 30 min of additional stirring at
room temperature the reaction mixture was diluted with
dichloromethane, washed with 5% aqueous sodium hydrogene
carbonate, dried, and concentrated. Purification by flash
column chromatography (toluene-ethyl acetate; 12:1) followed
by crystallization from diethyl ether-hexane gave compound
8 (4.36 g, 98%) as white needles: mp 76 °C; [R]22D 80.4° (c 0.96,
r a c-tr a n s-4,5-Bis(h yd r oxym eth yl)cycloh exen e [(()-7].
To a stirred suspension of lithium aluminum hydride (1.15 g,
30.2 mmol) in dry tetrahydrofuran (200 mL) rac-trans-4,5-bis-
(methoxycarbonyl)cyclohexene10 [(()-6, 4.20 g, 21.4 mmol] in
dry tetrahydrofuran (50 mL) was added dropwise at 0 °C. The
reaction mixture was stirred at room temperature for 3 h
before ethyl acetate (3 mL), water (2 mL), 10% aqueous sodium
hydroxide (2 mL), and water (2 mL) again were added. After
the mixture was stirred at room temperature for 3 h magne-
sium sulfate (23 g) was added and the stirring was prolonged
for additional 2 h. The precipitate and magnesium sulfate
were removed by filtration and washed several times with
ethyl acetate. Concentration and purification by flash column
chromatography (toluene-ethyl acetate; 2:1) gave compound
(()-7 (2.87 g, 93%) as a colorless syrup: 1H NMR (250.13 MHz,
CDCl3) δ 1.62-2.19 (m, 6 H), 2.97 (b, 2 H), 3.50-3.69 (dt, J )
11.0, 5.4 Hz, 2 H), 3.70-3.87 (dq, J ) 11.3, 4.8, 2.6 Hz, 2 H),
5.66 (m, 2 H); 13C NMR (62.90 MHz, CDCl3) δ 28.54, 39.75,
66.24, 126.05.
1
CHCl3); H NMR δ (250.13 MHz, CDCl3) 2.04-2.38 (m, 6 H),
4.77 (m, 4 H), 5.72 (s, 2 H), 7.31-8.09 (m, 10 H); 13C NMR
(62.90 MHz, CDCl3) δ 27.22, 34.61, 66.67, 125.37, 126.34,
129.53, 130.17, 132.91, 166.54. Anal. Calcd for C22H22O4: C,
75.41; H, 6.33. Found: C, 75.62; H, 6.26.
(4R,5R)-4,5-Bis[(b en zoyloxy)m et h yl]-1,2-ep oxycyclo-
h exa n e (9). To a solution of compound 8 (3.74 g, 10.7 mmol)
in dichloromethane (40 mL) was added m-chloroperoxybenzoic
acid (3.2 g, 13.0 mmol) in portions at room temperature, and
the reaction mixture was stirred for 4 h. The mixture was
diluted with dichloromethane, washed with aqueous saturated
sodium sulfite and aqueous sodium hydrogene carbonate,
dried, and concentrated. Crystallization from diethyl ether
and hexane gave compound 9 (3.42 g, 87%) as white needles:
Resolu tion of r a c-tr a n s-4,5-Bis(h yd r oxym etyl)cyclo-
h exen e [(()-7] Usin g Lip a se fr om P seu d om on a s sp .
(SAM-II) a s Ca ta lyst. A solution of compound (()-7 (5.60 g,
39.4 mmol), lipase from Pseudomanas sp. (SAM-II) (160 mg),
vinyl acetate (15 mL), and chloroform (66 mL) was stirred at
room temperature for 100 h until TLC indicated almost equal
transesterification to diacetate and monoacetate, with only
traces of unreacted diol. At this time the reaction mixture
was centrifuged, and the clear supernatant was decanted and
concentrated. Separation of the three products by column
chromatography (toluene-ethyl acetate; 6:1 to 1:2) gave (S,S)-
diacetate (S,S)-7b (3.89 g, 44%), (R,R)-monoacetate (R,R)-7a
(3.62 g, 50%), and unesterified (R,R)-diol (R,R)-7 (0.26 g, 5%;
75% ee). Compounds (S,S)-7b and (S,S)-7a were deacetylated,
respectively, with methanolic sodium methoxide (12 mL, 0.2
M) in methanol (50 mL), neutralized with Dowex-(H+), con-
centrated, and purified by column chromatography (toluene-
ethyl acetate; 1:2) to give (S,S)-diol (S,S)-7 (2.41 g, 98%, 89%
ee) and (R,R)-diol (R,R)-7 (2.74 g, 98%, 63% ee), respectively.
(4S,5S)-4,5-Bis(h yd r oxym eth yl)cycloh exen e [(S,S)-7].
The (S,S)-diol was crystallized from diethyl ether and hexane
to give enantiomerically pure (S,S)-diol (S,S)-7 (2.01 g, 36%):
mp 62-63 °C; [R]22 75.2o (c 0.80, CHCl3) (lit. [R]22 75.1°).19
mp 118-119 °C; [R]22 77.6° (c 0.88, CHCl3); 1H NMR (250.13
D
MHz, CDCl3) δ 1.69-2.42 (m, 6 H), 3.27 (m, 2 H), 4.34 (m, 4
H), 7.30-8.12 (m, 10 H); 13C NMR (62.90 MHz, CDCl3) δ 27.36,
28.76, 31.66, 34.40, 51.23, 52.46, 66.21, 66.44, 126.36, 129.51,
129.92, 132.99, 166.41. Anal. Calcd for C22H22O5: C, 72.11;
H, 6.05. Found: C, 72.22; H, 6.08.
(1R,4S,5R)-4,5-Bis[(ben zoyloxy)m eth yl]-1-h yd r oxycy-
cloh ex-2-en e (10). A 100-mL three-necked round-bottomed
flask was connected to argon, flame dried, and charged with
trimethylsilyl trifluoromethanesulfonate (1.64 mL, 9.0 mmol)
and dry toluene (10 mL). To this mixture was added com-
pound 9 (3.0 g, 8.2 mmol), 1,8-diazabicyclo[5.4.0]undec-7-en
(1.52 mL, 10.2 mmol) in dry toluene (11 mL). The reaction
mixture was stirred at room temperature for 20 h before
trimethylsilyl trifluoromethanesulfonate (1.64 mL, 9.0 mmol)
and 1,8-diazabicyclo[5.4.0]undec-7-ene (1.52 mL, 10.2 mmol)
were added again. After 20 h of additional stirring the reaction
mixture was diluted with toluene, washed with aqueous 0.1
M hydrochloric acid and aqueous sodium hydrogen carbonate,
dried, and concentrated. The crude product was dissolved in
methanol (70 mL) and aqueous hydrochloric acid (24 mL, 2
M), and the reaction mixture was stirred at room temperature
for 5 h. The mixture was neutralized with sodium hydrogen
carbonate, diluted with water, extracted with dichloromethane,
D
D
Anal. Calcd for C8H14O2: C, 67.58; H, 9.92. Found: C, 67.38;
H, 10.08.
(4R,5R)-4,5-Bis(h yd r oxym eth yl)cycloh exen e [(R,R)-7].
The (R,R)-diol was crystallized from diethyl ether and hexane

Purines as Potential Inhibitors of HIV
J . Org. Chem., Vol. 61, No. 18, 1996 6287
and dried. Concentration and purification by column chro-
matography (toluene-ethyl acetate, 1:4) gave compound 10
(2.59 g, 86%) as a colorless syrup: [R]22D 31.3° (c 0.67, CHCl3);
1H NMR (250.13 MHz, CDCl3) δ 1.72-1.82 (m, 1 H); 1.82-
2.06 (m, 2 H), 2.39 (m, 1 H), 2.60 (m, 1 H), 4.32 (m, 1 H), 4.28-
4.53 (m, 4 H), 5.85 (dd, J ) 10.1, 2.3 Hz, 1 H), 5.94 (dq, J )
10.1, 3.7, 2.3 Hz, 1 H), 7.38-8.10 (m, 10 H); 13C NMR (62.90
MHz, CDCl3) δ 31.48, 33.26, 37.59, 63.44, 66.16, 66.66, 125.26,
126.40, 129.02, 129.56, 129.98, 130.43, 130.62, 133.04, 166.44.
Anal. Calcd for C22H22O5: C, 72.11; H, 6.05. Found: C, 71.87;
H, 6.08.
2.09 (m, 4 H), 3.22-3.75 (m, 4 H), 4.54 (b, 1 H), 4.79 (b, 1 H),
4.93 (m, 1 H), 5.82 (dq, J ) 10.0, 4.4, 2.0 Hz, 1 H), 6.05 (dq, J
) 10.0, 2.7, 1.0 Hz, 1 H), 6.65 (s, 2 H), 7.68 (s, 1 H), 9.90 (b, 1
H); 13C NMR (62.90 MHz, DMSO-d6) δ 30.60, 32.09, 40.81
(hidden in DMSO-d6, detected in MeOH-d4), 47.17, 62.36,
63.00, 116.94, 124.29, 136.16, 136.24, 150.72, 153.61, 157.09.
Anal. Calcd for C13H17O3N51.0H2O: C, 50.48; H, 6.19; N,
22.64. Found: C, 50.62; H, 5.93; N, 22.31.
(1R,4S,5R)-9-[4,5-Bis(h yd r oxym eth yl)cycloh exa n -1-yl]-
9H-a d en in e (14). A suspension of compound 12 (0.028 g, 0.10
mmol) and 10% palladium on carbon (25 mg) in methanol (3.0
mL) was hydrogenated at atmospheric pressure for 24 h. The
reaction mixture was filtered through celite and concentrated.
Purification by column chromatography (chloroform-metha-
(1R,4S,5R)-1-Acet oxy-4,5-b is[(b en zoyloxy)m et h yl]cy-
cloh ex-2-en e (11). Compound 10 (1.14 g, 3.1 mmol) was
dissolved in pyridine (22 mL) and acetic anhydride (11 mL)
was added. After stirring at room temperature for 3 h the
reaction mixture was concentrated, codistilled with toluene,
and purified by flash column chromatography (toluene-ethyl
nol; 3:1) gave compound 14 (0.028 g, 98%): [R]22
D -2.3° (c 0.87,
1
DMSO); H NMR (250.13 MHz, DMSO-d6) δ 1.61-2.32 (m, 8
H), 3.47-3.71 (m, 4 H), 4.39-4.76 (m, 3 H), 7.15 (b, 2 H), 8.11
(s, 1 H), 8.23 (s, 1 H); 13C NMR (62.90 MHz, DMSO-d6) δ 22.26,
27.66, 29.12, 36.31, 37.04, 50.01, 62.47, 62.77, 119.07, 139.35,
149.27, 152.10, 156.03. Anal. Calcd for C13H19O2N5‚1.0H2O‚
0.2MeOH: C, 52.54; H, 7.28; N, 23.21. Found: C, 52.40; H,
7.24; N, 22.91.
acetate, 6:1) to give compound 11 (1.22 g, 96%) as a colorless
1
syrup: [R]22 -24.0° (c 0.85, CHCl3); H NMR (250.13 MHz,
D
CDCl3) δ 1.84-2.11 (m, 2 H), 2.05 (s, 3 H), 2.38 (m, 1 H), 2.64
(m, 1 H), 4.38-4.56 (m, 4 H), 5.33 (m, 1 H), 6.00 (m, 2 H),
7.35-8.10 (m, 10 H); 13C NMR (62.90 MHz, CDCl3) δ 21.25,
30.34, 31.62, 37.54, 65.67, 66.10, 66.63, 126.40, 126.77, 129.57,
129.96, 132.72, 133.08, 166.38, 170.55. Anal. Calcd for
C24H24O6: C, 70.57; H, 5.92. Found: C, 70.47; H, 5.96.
(1S,4S,5R)-9-[4,5-Bis(h yd r oxym eth yl)cycloh ex-2-en -1-
yl]-9H-a d en in e (12). To a stirred solution of adenine (0.18
g,1.3 mmol) in dry dimethylformamide (3.0 mL) was added
sodium hydride (80% dispersion in oil, 0.037 g, 1.2 mmol), and
the reaction mixture was stirred at room temperature under
argon for 2 h. This frothy suspension was added dropwise to
(1R,4S,5R)-9-[4,5-Bis(h yd r oxym eth yl)cycloh exa n -1-yl]-
9H-gu a n in e (15). Compound 13 (0.045 g, 0.15 mmol) was
hydrogenated as described for preparation of compound 14.
Purification by preparative high-pressure liquid chromatog-
raphy (water-methanol, 80:20, v/v) gave compound 15 (0.043
g, 95%): [R]22 3.2° (c 1.16 DMSO); 1H NMR (250.13 MHz,
D
DMSO-d6) δ 1.57-2.20 (m, 8 H), 3.47-3.65 (m, 4 H), 4.35 (m,
1 H), 4.58 (b, 2 H), 6.75 (b, 1 H), 7.77 (s, 1 H), 9.92 (b, 1 H);
13C NMR (62.90 MHz, DMSO-d6) δ 22.30, 28.20, 29.14, 36.33,
37.04, 49.09, 62.47, 62.84, 116.64, 135.58, 150.77, 153.30,
156.95. Anal. Calcd for C13H19O3N5‚1.1H2O ‚0.4MeOH: C,
49.65; H, 6.30; N, 21.67. Found: C, 49.61; H, 6.68; N, 21.91.
(1R,4S,5R)-9-[4,5-Bis(h yd r oxym eth yl)cycloh ex-2-en -1-
yl]-9H-a d en in e (16). A 100-mL three-necked round-bottomed
flask was connected to argon, flame dried, and charged with
6-chloropurine (0.29 g, 3.1 mmol), triphenylphosphine (0.49
g, 1.9 mmol) and dry tetrahydrofuran (11 mL). To the mixture
was added dropwise diisopropyl azocarboxylate (0.37 mL, 1.9
mmol), and the resulting mixture was stirred at 0 °C for 30
min under argon. The reaction mixture was cooled to -78 °C
before a suspension of 10 (0.46 g, 1.25 mmol) in dry tetrahy-
drofuran (5.5 mL) was added, and the mixture was stirred at
0 °C for 24 h. The solvent was evaporated and the residue
was purified by column chromatograpy (toluene-ethyl acetate;
1:1) to give the protected 6-chloropurine derivative. A solution
of the protected 6-chloropurine derivative in dry methanol (3.0
mL) was saturated with ammonia(g) and then heated in a
bomb at 80 °C for 48 h. The ammonia was evaporated off
under a stream of argon before the resulting solution was
concentrated and purified by column chromatography (chlo-
roform-methanol; 3:1) to give compound 16 (0.18 g, 52%):
a
suspension of 11 (0.42 g, 1.2 mmol) and tetrakis(tri-
phenylphosphine)palladium(0) (0.048 g, 0.04 mmol) in dry
tetrahydrofuran (3.0 mL) under argon. The reaction mixture
was immersed in a preheated oil bath (60 °C) and stirred for
20 h. After the mixture was cooled to room temperature,
concentrated and purified by column chromatography (chlo-
roform-methanol; 10:1), the protected adenine derivative was
obtained. A solution of the protected adenine derivative in
dry methanol (4.0 mL) was saturated with ammonia(g) and
then heated in a bomb at 80 °C for 48 h. The ammonia was
evaporated off under a stream of argon before the resulting
solution was concentrated and purified by column chromatog-
raphy (chloroform-methanol; 3:1) to give compound 12 (0.19
g, 69%): [R]22 -50.8° (c 0.66 DMSO); UV (H2O) λmax 262.2
D
1
nm; H NMR (250.13 MHz, DMSO-d6) δ 1.72-2.10 (m, 4 H),
3.22-3.75 (m, 4 H), 4.54 (t, J ) 5.3 Hz; 1 H), 4.81 (t, J ) 5.3
Hz, 1 H), 5.15 (m, 1 H), 5.92 (dq, J ) 9.9, 4.2, 2.0 Hz, 1 H),
6.18 (dq, J ) 10.0, 2.5, 1.2 Hz, 1 H) 7.22 (b, 2H), 8.02 (s, 1 H);
13C NMR (62.90 MHz, DMSO-d6) δ 30.45, 32.31, 40.87 (hidden
in DMSO-d6, detected in MeOH-d4), 47.61, 62.40, 62.94, 119.22,
124.26, 136.33, 139.64, 149.10, 152.36, 156.07. Anal. Calcd
for C13H17O2N5: C, 56.71; H, 6.22; N, 25.44. Found: C, 56.66;
H, 6.19; N, 25.25 .
[R]22
D 122.0° (c 1.00 DMSO); UV (H2O) λmax 261.6 nm; 1H NMR
(250.13 MHz, DMSO-d6) δ 1.59-2.28 (m, 4 H), 3.16-3.71 (m,
4 H), 4.64 (t, J ) 5.2 Hz, 1 H), 4.74 (t, J ) 5.2 Hz, 1 H), 5.08
(m, 1 H), 5.85 (d, J ) 10.1 Hz, 1 H), 6.02 (dt, J ) 10.2, 2.3
Hz), 7.22 (b, 2 H), 8.07 (s, 1 H), 8.12 (s, 1 H); 13C NMR (62.90
MHz, DMSO-d6) δ 33.36, 37.55, 40.06 (hidden in DMSO-d6,
detected in MeOH-d4), 51.33, 63.03, 63.27, 119.00, 127.09,
(1S,4S,5R)-9-[4,5-Bis(h yd r oxym eth yl)cycloh ex-2-en -1-
yl]-9H-gu a n in e (13). To a stirred solution of 2-amino-6-
chloropurine (0.24 g, 1.4 mmol) in dry dimethylformamide (3.0
mL) was added sodium hydride (80% dispersion in oil, 0.038
g, 1.3 mmol), and the reaction mixture was stirred at room
temperature under argon for 2 h. This frothy suspension was
added dropwise to a suspension of 11 (0.44 g, 1.1 mmol) and
tetrakis(triphenylphosphine)palladium(0) (0.049 g, 0.04 mmol)
in dry tetrahydrofuran (3.0 mL) under agron. The reaction
mixture was immersed in a preheated oil bath (60 °C) and
stirred for 20 h. After the mixture was cooled to room
temperature, concentrated, and purified by column chroma-
tography (toluene-ethyl acetate; 1:1), the protected 2-amino-
6-chloropurine derivative was obtained. A solution of the
protected 2-amino-6-chloropurine derivative in aqueous sodium
hydroxide (8.0 mL, 1.0 M) was refluxed for 4 h. The reaction
mixture was neutralized with aqueous hydrochloric acid (2 M).
Concentration, filtration through a column of Sephadex LH-
20 (water), and purification by preparative high-pressure
liquid chromatography (water-methanol, 80:20, v/v) gave
133.89, 138.92, 149.26, 152.35, 156.04. Anal. Calcd for C13H17
-
O2N5: C, 56.71; H, 6.22; N, 25.44. Found: C, 56.46; H, 6.37;
N, 25.32.
(1R,4S,5R)-9-[4,5-Bis(h yd r oxym eth yl)cycloh ex-2-en -1-
yl]-9H-gu a n in e (17). A 100-mL, three-necked, round-bot-
tomed flask was connected to argon, flame dried, and charged
with 2-amino-6-chloropurine (0.31 g, 1.8 mmol), triphenylphos-
phine (0.47 g, 1.8 mmol), and dry tetrahydrofuran (10 mL).
To the mixture was added dropwise diisopropyl azocarboxylate
(0.36 mL, 1.8 mmol), and the resulting mixture was stirred at
0 °C for 30 min. The reaction mixture was cooled to -78 °C
before a suspension of 10 (0.44 g, 1.2 mmol) in dry tetrahy-
drofuran (5.0 mL) was added, and the mixture was stirred at
0 °C for 24 h. The solvent was evaporated and the residue
was purified by column chromatography (toluene-ethyl ac-
etate; 1:1) to give the protected 2-amino-6-chloropurine deriva-
compound 13 (0.14 g, 46%): [R]22 10.3° (c 0.98, DMSO); UV
D
(H2O) λmax 252.8 nm; 1H NMR (250.13 MHz, DMSO-d6) δ 1.61-

6288 J . Org. Chem., Vol. 61, No. 18, 1996
Rosenquist et al.
tive. A solution of the protected 2-amino-6-chloropurine
derivative in aqueous sodium hydroxide (6.5 mL, 0.5 M) was
refluxed for 4 h. After the mixture was cooled to room
temperature the pH was adjusted to 7 with 2 M aqueous
hydrochloric acid. Concentration, filtration through a column
of Sephadex LH-20 (water), and purification by preparative
high-pressure chromatography (water-methanol, 80:20, v/v)
H), 3.32-3.60 (m, 4 H), 4.10 (b, 1 H), 4.25 (b, 1 H), 4.57 (m, 1
H), 7.18 (b, 2 H), 8.09 (s, 1 H), 8.14 (s, 1 H); 13C NMR (62.90
MHz, DMSO-d6) δ 28.52, 31.61, 35.71, 40.32, 40.72, 53.70,
63.15, 119.07, 139.01, 149.13, 152.15, 156.02. Anal. Calcd for
C
13H19O2N5‚0.75MeOH: C, 54.80; H, 7.35; N, 23.24. Found:
C, 54.77; H, 7.05; N, 23.04.
(1S,4S,5R)-9-[4,5-Bis(h yd r oxym eth yl)cycloh exa n -1-yl]-
9H-gu a n in e (19). Compound 17 (0.036 g, 0.12 mmol) was
hydrogenated as described for preparation of compound 18.
Purification by HPLC (water-methanol, 80:20, v/v) gave
gave compound 17 (0.12 g, 34%): [R]22 25.1° (c 0.84, DMSO);
D
1
UV (H2O) λmax 253.0 nm; H NMR (250.13 MHz, DMSO-d6) δ
1.54-2.12 (m, 4 H), 3.18-3.71 (m, 4 H), 4.42-5.90 (b, 2 H),
4.98 (m, 1 H), 5.83 (d, J ) 10.2 Hz, 1 H), 5.99 (dt, J ) 10.0,
2.0 Hz, 1 H), 6.71 (b, 2H), 7.78 (s, 1 H), 9.89 (b, 1 H); 13C NMR
(62.90 MHz, DMSO-d6) δ 33.59, 37.56, 40.07 (hidden in DMSO-
d6, detected in MeOH-d4), 50.65, 62.97, 63.26, 116.67, 127.11,
compound 19 (0.034 g, 93%): [R]22 -12.2° (c 1.08, DMSO);
D
1H NMR (250.13 MHz, DMSO-d6) δ 1.15-2.02 (m, 8 H), 3.18-
3.63 (m, 4 H), 4.08 (m, 1 H), 4.47-4.59 (dt, J ) 5.2, 5.1 Hz, 2
H), 6.48 (b, 2 H), 7.72 (s, 1 H), 9.95 (b, 1 H); 13C NMR (62.90
MHz, DMSO-d6) δ 28.58, 31.68, 35.94, 40.58, 40.79, 52.91,
63.13, 116.69, 135.18, 150.66, 153.42, 156.95. Anal. Calcd for
133.95, 134.93, 150.93, 153.63, 157.01. Anal. Calcd for C13H17
-
O3N5‚2.0H2O: C, 47.69; H, 6.47; N, 21.39. Found: C, 47.39;
H, 5.68; N, 20.75. This was the best result obtained after
repeated purification and duplicated elemental analysis.
(1S,4S,5R)-9-[4,5-Bis(h yd r oxym eth yl)cycloh exa n -1-yl]-
9H-a d en in e (18). A suspension of compound 16 (0.058 g, 0.21
mmol) and 10% palladium on carbon (40 mg) in methanol (4.0
mL) was hydrogenated at atmospheric pressure for 24 h. The
reaction mixture was filtered through celite and concentrated.
Purification by column chromatography (chloroform-metha-
C
13H19O3N5‚0.8H2O‚0.2MeOH: C, 50.46; H, 6.86; N, 22.29.
Found: C, 50.69; H, 6.53; N, 22.09.
Ack n ow led gm en t. We thank the National Swedish
Board for Technical Development and Medivir AB for
financial support and Medivir AB for the biological
testings.
nol; 3:1) gave compound 18 (0.058 g, 99%): [R]22 3.5° (c 1.3,
D
1
DMSO); H NMR (250.13 MHz, DMSO-d6) δ 1.18-2.09 (m, 8
J O9603542