Electrolytic Partial Fluorination of Organic Compounds.71. Highly Diastereoselective Anodic Fluorination of Sulfides Having Oxygen-Containing Heterocyclic Groups

Article abstract of DOI:10.1021/jo035291j

Diastereoselective anodic fluorination of sulfides having various oxygen-containing heterocyclic substituents such as 2-furanyl, 1,3-dioxolanyl, 2,2-dimethyl-1,3-dioxolanyl, 2-spirocyclohexyl-1,3-dioxolanyl, 2-spiroadamantyl-1,3-dixolanyl, and 1,3-dioxolanonyl groups at the β-position was comparatively studied. Among the oxygen-containing heterocyclic substituents, the 2-spirocyclohexyl-1,3-dioxolanyl group gave the best diastereoselectivity (80% de). The diastereoselectivity was also affected by supporting fluoride salts and solvents. Chemical fluorination using selectfluor resulted in much lower diastereoselectivity and extremely poor yield. The fluorinated products were readily converted into the corresponding fluorinated diol in good yields by acidic hydrolysis.

Full text of DOI:10.1021/jo035291j

Electr olytic P a r tia l F lu or in a tion of Or ga n ic Com p ou n d s.71.1
High ly Dia ster eoselective An od ic F lu or in a tion of Su lfid es Ha vin g
Oxygen -Con ta in in g Heter ocyclic Gr ou p s
Katsutoshi Suzuki and Toshio Fuchigami*
Department of Electronic Chemistry, Tokyo Institute of Technology,
Nagatsuta, Midori-ku, Yokohama 226-8502, J apan
fuchi@echem.titech.ac.jp
Received September 3, 2003
Diastereoselective anodic fluorination of sulfides having various oxygen-containing heterocyclic
substituents such as 2-furanyl, 1,3-dioxolanyl, 2,2-dimethyl-1,3-dioxolanyl, 2-spirocyclohexyl-1,3-
dioxolanyl, 2-spiroadamantyl-1,3-dixolanyl, and 1,3-dioxolanonyl groups at the â-position was
comparatively studied. Among the oxygen-containing heterocyclic substituents, the 2-spirocyclo-
hexyl-1,3-dioxolanyl group gave the best diastereoselectivity (80% de). The diastereoselectivity was
also affected by supporting fluoride salts and solvents. Chemical fluorination using selectfluor
resulted in much lower diastereoselectivity and extremely poor yield. The fluorinated products were
readily converted into the corresponding fluorinated diol in good yields by acidic hydrolysis.
SCHEME 1
In tr od u ction
Although a diastereoselective fluorination with an
electrophilic reagent proceeds with high diastereoselec-
tivity, a diastereoselective nucleophilic fluorination is
generally difficult, probably because of the smallness of
the fluoride ion and the necessity of the use of polar
solvents for electric conductivity.2 Therefore, only a few
studies have been reported on diastereoselective anodic
fluorination.2 Kabore et al. obtained up to 60% de in the
anodic fluorination of R-phenylacetates having various
chiral auxiliaries,3 while we obtained a much lower de
of 20% in the anodic fluorination of R-phenylthioacetates
having similar chiral auxiliaries.4 Quite recently, we
reported a highly diastereoselective anodic fluorination
of N-acylthiazolidines derived from L-cysteine5 and chiral
1,3-oxothiolan-5-ones derived from champhorsulfon-
amide.6 On the other hand, chiral fluorine-containing 1,2-
diols are useful building blocks for the preparation of
valuable organofluorine compounds such as fluorinated
sugars.7 However, their preparation methods are limited.
Therefore, the development of new synthetic methods for
fluorinated diols is of much importance.8
In this study, we carried out successfully highly
diastereoselective anodic fluorination of sulfides having
oxygen-containing heterocycles and converted the fluori-
nated sulfides to the corresponding chiral fluorine-
containing diol.
Resu lts a n d Discu ssion
At first, anodic fluorination of (R)-4-[(phenylthio)-
methyl]-2-spirocyclohexyl-1,3-dioxolane (1a ) as a model
compound was carried out in acetonitrile (MeCN) con-
taining various supporting fluoride salts. The electrolysis
was conducted at a constant current, and 2 F/mol of
electricity was passed. The results are shown in Scheme
1 and Table 1. Among the supporting electrolytes used,
Et3N‚3HF was the most suitable for the anodic fluorina-
tion since its use provided the highest diastereoselectivity
and yield. In a strongly acidic solution, the deprotection
of the diol moiety of 1a took place; therefore, the desired
anodic fluorinations did not proceed at all (runs 4-6).
Thus, both the yield and diastereoselectivity of the anodic
fluorination were found to be greatly affected by sup-
porting fluoride salts.
* To whom correspondence should be addressed. Phone: +81-45-
924-5406. Fax: +81-45-924-5489.
(1) Part 70: Hasegawa, M.; Ishii, H.; Fuchigami, T. Green Chem.
2003, 5, 512.
(2) (a) Hiyama, T. Organofluorine Compounds. Chemistry and
Applications; Springer: Berlin, 2000. (b) Fuchigami, T. Organic
Electrochemistry, 4th ed.; Lund. H., Hammerich, J . O., Eds.; Marcel
Dekker: New York.
(3) Kabore, L.; Chebli, S.; Faure, R.; Laurent, E.; Marquet, B.
Tetrahedron Lett. 1990, 31, 3137.
(4) Narizuka, S.; Koshiyama, H.; Fuchigami, T. J . Fluorine Chem.
1995, 31, 121.
(5) Baba, D.; Ishii, H.; Higashiya, S.; Fujisawa, K.; Fuchigami, T.
J . Org. Chem. 2001, 66, 7020.
(6) Baba, D.; Yi-J en Yang.; Biing-J iun Uang.; Fuchigami, T, J .
Fluorine. Chem. 2003, 121, 93.
Next, the solvent effect on the anodic fluorination of
1a was investigated using various solvents containing
(7) Takamatsu, S.; Katayama, S.; Izawa, K. Nucleosides, Nucleotides
Nucleic Acids 2002, 21, 849.
(8) Itoh, T.; Sakabe, K.; Kudo, K.; Ohara, H.; Takagi, Y.; Kihara,
H.; Zagatti, P.; Renou, M. J . Org. Chem. 1999, 64, 252.
10.1021/jo035291j CCC: $27.50 © 2004 American Chemical Society
Published on Web 01/27/2004
1276
J . Org. Chem. 2004, 69, 1276-1282

Electrolytic Fluorination of Organic Compounds
TABLE 1. Effect of Su p p or tin g Electr olytes on th e
An od ic F lu or in a tion of 1a a
TABLE 3. Tem p er a tu r e Effect on th e An od ic
F lu or in a tion of 1a
supporting
electrolyte
yieldb
(%)
deb,c
(%)
charge passed temp yielda dea
run
run
solvent
MeCN
MeCN
MeCN
DME
DME
DME/MeCN (1:1)
DME/MeCN (1:1)
(F/mol)
(°C)
(%)
(%)
1
2
3
4
5
6
Et3N‚2HF
Et3N‚3HF
Et3N‚4HF
Et3N‚5HF
Et4NF‚3HF
Et4NF‚4HF
8
54
6
0
trace
0
62
80
58
1
8
3
3
6
5
5
3
0
20
40
20
40
20
40
31
66
45
89
90
92
>99
76
80
78
51
52
61
59
2
3b
4
5
6
7
Charge passed 2 F/mol. Determined by 19F NMR. c The
absolute configuration of the major diastereomer is (1R,2S).
a
b
a
b
Determined by 19F NMR. Difluoroination of monofluorinated
product 2a also took place.
TABLE 2. Solven t Effect on th e An od ic F lu or in a tion of
1a a
SCHEME 2
solvent
(DN)b
yieldc
(%)
dec
(%)
run
1
2
3
4
5
6
7
CH2Cl2 (0)d
NM (2.7)
MeCN (14.1)
dioxane (14.8)
PC (15.1)
60
0
69
54
14
43
62
0
80
64
58
51
DME (20.0)
DMSO (29.8)
a
b
Charge passed 2 F/mol. Gutmann’s donor number. c Deter-
tion in MeCN was investigated at various temperature
as shown in Table 3. At a low temperature such as 0 °C,
the anodic fluorination did not proceed effectively and a
large excess amount of electricity was required to com-
plete the electrolysis (run 1).
At a higher temperature such as 20 °C, the yield was
increased significantly and the required amount of
electricity was decreased to 3 F/mol (run 2). As we have
already reported previously,11 the deprotonation of the
fluorosulfonium ion intermediate (A) in the rate-deter-
mining step from A to B in Scheme 2 should be facilitated
at a higher temperature.
However, at 40 °C, the yield decreased since difluori-
nation took place simultaneously (run 3). On the other
hand, the anodic fluorination proceeded efficiently in
DME to provide a good yield (runs 4 and 5) since DME
enhances the nucleophilicity of fluoride ions, as reported
previously.10,11-13 Even at 40 °C, no difluorination took
place because DME was sacrificially (simultaneously)
oxidized instead of monofluorinated product 2a once
formed.
In DME solely as an electrolytic solvent, a large excess
amount of electricity was required because of its simul-
taneous oxidation. Since MeCN is rather stable against
anodic oxidation, a mixed solvent of DME/MeCN (1:1)
was used for the anodic fluorination (runs 6 and 7). An
excellent yield and much better current efficiency were
achieved at 40 °C (run 7).14 However, the diastereoselec-
tivity was much lower than that in MeCN. Interestingly,
the diastereoselectivity (de) was not affected appreciably
by temperature although de was changed significantly
depending on the solvents. Thus, high diastereoselectivity
(80% de) was obtained in MeCN although the yield was
moderate (run 2).
mined by 19F NMR. Donor number estimated from CH2ClCH2Cl
(DN ) 0).
d
Et3N‚3HF. The results at 2 F/mol of electricity passed
are shown in Table 2. The solvents also affected consider-
ably the anodic fluorination. Higher yields were obtained
in DME and dichloromethane compared with acetonitrile.
DMSO and nitromethane were not suitable for the
fluorination.
Among the solvents used, acetonitrile gave the highest
diastereoselectivity. Notably, the diastereoselectivity in-
creased with a decrease in the donor number9 (DN) of
solvents except for dichloromethane. This can be ex-
plained in terms of the decrease of the nucleophilicity
(reactivity) of fluoride ions in solvents having smaller
donor numbers.10 In support of this, we measured 19F
NMR spectra of Et3N‚3HF in DME, dioxane, MeCN, and
CH2Cl2. Previously, we observed the fluorine signal of
fluoride ions of Et4NF‚nHF (n ) 3, 4) in solvents having
larger donor numbers at higher magnetic field since such
solvents solvate more strongly the cations of Et3N‚3HF
to make the fluoride ions naked like KF in crown ethers.10
In fact, it was found that the fluorine signal due to Et3N‚
3HF in DME appeared at higher magnetic field (δ -98.8
ppm) than that in PC (δ -98.5 ppm), dioxane (δ -97.4
ppm), AN (δ -97.1 ppm), and CH2Cl2 (δ -96.2 ppm). On
the other hand, no clear correlation of yield and DN was
observed because the electrochemical fluorination was
also influenced by the electrochemical stability (runs 4
and 6) and the viscosity (runs 4 and 5) of the electrolytic
solvents.
Thus, it was found that electrolytic solvents affected
significantly the diastereoselectivity as well as the yield.
Next, the temperature effect on electrochemical fluo-
rination was investigated. The reactions were carried out
until starting materials were consumed completely (moni-
tored by gas chromatography). At first, anodic fluorina-
(11) Fuchigami, T.; Konno, A.; Nakagawa, K.; Shimojo, M. J . Org.
Chem. 1994, 59, 5937.
(12) Ishii, H.; Yamada, N.; Fuchigami, T. Chem. Commun. 2000,
1617.
(13) Shaban, M. R.; Ishii, H.; Fuchigami, T. J . Org. Chem. 2000,
65, 8685.
(9) Gutmann, V.; Wychera. Inorg. Nucl. Chem. Lett. 1996, 2, 257.
(10) Hou, Y.; Fuchigami, T. J . Electrochem. Soc. 2000, 147, 4567.
(14) Suzuki, K.; Ishii, H.; Fuchigami, T. Tetrahedorn Lett. 2001, 42,
4861.
J . Org. Chem, Vol. 69, No. 4, 2004 1277

Suzuki and Fuchigami
TABLE 4. An od ic F lu or in a tion of Su lfid es Ha vin g Oxygen -Con ta in in g Heter ocyclic a n d Oxygen Su bstitu en ts
a
b
Determined by 19F NMR. Isolated yield. c The absolute configuration of the major diastereomer is (1R,2S).
Since anodic fluorination of 1a in Et3N‚3HF/MeCN at
20 °C gave the highest diastereoselectivity, anodic fluo-
rination of sulfides having various oxygen-containing
heterocyclic and open-chain alkoxy groups was examined.
To compare the diastereoselectivity, 2 F/mol of electricity
was passed (the starting sulfides were not always con-
sumed completely). The results are shown in Table 4.
The low yields in some cases are due to the recovered
starting materials. The de values of the fluorinated
sulfides would be changed during the electrolysis if their
carbon-fluorine bond cleavage/formation were reversible
in the electrolytic solution. To confirm this point, the
fluorinated product 2a was left overnight in the electro-
lytic solution at room temperature. However, the de value
did not change at all. The diastereoselectivity of the
anodic fluorination of sulfide 5 having two methoxy
groups is much higher than that of sulfide 3 with one
methoxy group. However, sulfide 7 having a 2-furanyl
group also showed the same de as sulfide 5. These results
may suggest that a γ-substituent as well as a γ-methoxy
one play an important role in the diastereoselectivity.
Next, the protecting group effect of 1,2-diol moieties on
the regioselective anodic fluorination was investigated.
Although the dimethyl group in the dioxolanyl group
made de slightly increase (run 9), the spirocyclohexyl
group was very effective for the diastereoselectivity and
80% de was obtained in the case of 1a (run 1). This result
seems to suggest that bulkier protecting groups would
give higher de. However, the extremely bulky spiro-
adamantyl group decreased the diastereoselectivity, and
the de was lower compared with that of the smallest
protecting group (sulfide 9, run 8). In sharp contrast to
these protecting groups, a carbonyl protecting group of
sulfide 15 decreased the de drastically to 13% (run 11).
Furthermore, anodic fluorination of para-substituted
phenyl sulfides 1b-d was carried out to investigate the
substituent effect on the diastereoselectivity (runs 2-4).
The fluorination of 1d having an electron-donating
methoxy group did not proceed. In contrast, the sulfides
containing electron-withdrawing groups such as chloro
and nitro groups underwent anodic fluorination more
efficiently than 1a , but the diastereoselectivity was lower
(1b) or much lower (1c) compared with that of 1a . These
results suggest that the cationic character of the anodi-
cally generated sulfenium ion intermediate B (Scheme
2) also appreciably affects the diastereoselectivity. Thus,
it was found that the diastereoselectivity of the anodic
fluorination of sulfides is not always controlled by their
molecular bulkiness.
Determination of the stereochemistry of major isomers
was attempted by their X-ray analyses. However, suitable
crystals of fluorinated products for the X-ray crystal
structure analysis were not obtained. After many at-
tempts, a suitable crystalline form of the major dia-
stereomer of 18 was obtained by the anodic fluorination
of p-nitrophenyl sulfide 17 having a 1,3-dioxolanonyl
group (Scheme 3).
Since X-ray analysis of the major diastereomer of 18
shows that the configuration is (1R,2S), the configuration
of other major isomers is assumed to be (1R,2S). On the
1278 J . Org. Chem., Vol. 69, No. 4, 2004

Electrolytic Fluorination of Organic Compounds
SCHEME 3
SCHEME 5
SCHEME 4
SCHEME 6
basis of this result, we considered the detailed mecha-
nism of the stereochemical control in nucleophilic reac-
tions as shown in Scheme 4 using the Felkin-Anh model
generally employed for this type of reaction via a cationic
intermediate.
SCHEME 7
For the two possible conformations C and D, fluoride
ion attack at the activated carbon atom is usually
explained to occur from the other side of the perpendicu-
lar C-O bond, and conformation D should experience less
steric repulsion with the incoming fluoride with the
possible electrostatic attraction of the â-oxygen atom and
the sulfenium ion. Thus, the reaction of a fluoride ion
was realized from the si face of conformation D, leading
to the formation of the (1R,2S) isomer, which is totally
consistent with the above X-ray analysis data. Conforma-
tion D is preferable as long as a suitably bulky protecting
group is employed and good to excellent diastereoselec-
tivity is obtained, but the use of the extremely hindered
spiroadamantyl group decreased the diastereoselectivity.
This can be explained as the result of the increased
instability of D and allowing the reaction path through
C to some extent.
In the case of sulfide 15, the electron density of the
ring oxygen atoms should decrease due to the electron-
withdrawing carbonyl group, which decreases the elec-
trostatic attraction of 15 (D′ conformation), as shown in
Scheme 5. Therefore, conformation C′ becomes more
favorable than D′. Thus, a fluoride ion also attacks the
activated carbon of C′. Consequently, the diastereoselec-
tivity of the fluorination of 15 decreases.
since it is known that the fluorination of sulfides proceeds
via a fluorosulfonium ion intermediate.14b We attempted
the chemical fluorination of 1a using various N-fluoro-
pyridinium salts A-C as shown in Scheme 6. However,
the fluorinations did not proceed at all. In the case of
weakly fluorinating reagent A, the starting material was
mostly recovered, while the use of strongly fluorinating
reagents B and C caused decomposition.
Additionally, we used selectfluor16 for the fluorination
of 1a , and the desired fluorinated product was obtained;
however, both the yield and de were much lower than
those of electrochemical fluorination as shown in Scheme
7. In this case, the starting material 1a was mostly
recovered. Hence, the electrochemical fluorination proved
to be a useful way for diastreoselective fluorination of
sulfides having diol moieties.
In the final part of this paper, we examine the
deprotection of fluorinated products. Acid hydrolysis of
N-Fluoropyridinium salts have been widely used for
the selective fluorination of various organic compounds
in recent years.15 They are safe, easy to handle, and
commercially available. It was expected that the fluori-
nation would proceed similarly to the anodic fluorination
(15) (a) Umemoto, T.; Kawado, K.; Tomita, K. Tetrahedoron Lett.
1986, 27, 4465. (b) Umemoto, T.; Tomizawa, G. Bull. Chem. Soc. J pn.
1986, 59, 3625. (c) Umemoto, T.; Tomizawa, G. J . Org. Chem. 1995,
60, 6563.
(16) Lal, G. S. J . Org. Chem. 1993, 58, 2791.
J . Org. Chem, Vol. 69, No. 4, 2004 1279

Suzuki and Fuchigami
SCHEME 8
an undivided PP (polypropylene) cell under a nitrogen atmo-
sphere. After the electrolysis, the resulting electrolytic solution
was subjected to short column chromatography on silica gel
using ethyl acetate to remove the fluoride salt. The eluent was
evaporated under vacuum, and the residue was purified by
silica gel column chromatography (hexane:EtOAc ) 4-9:1).
Da ta for (R)-4-[(p h en ylth io)m eth yl]-2-sp ir ocycloh exyl-
1,3-d ioxola n e (1a ): [R]2D2 +6.7 (c 0.1, CHCl3); 1H NMR
(CDCl3) δ 7.38-7.18 (5H, m), 4.26-4.21 (1H, m), 4.05 (1H, dd,
J ) 8.6, 5.9 Hz), 3.74 (1H, dd, J ) 8.4, 5.7 Hz), 3.26-2.88 (2H,
m), 1.65-1.38 (10H, m) ppm; 13C NMR (CDCl3) δ 135.3, 129.5,
128.8, 126.2, 110.1, 74.3, 68.3, 37.3, 35.0, 25.1, 24.0, 23.8 ppm;
MS (m/z) 264 (M+), 141 (M+ - CH2SC6H5); HRMS (m/z) calcd
for C15H20O2S 264.1184, found 264.1184. Anal. Calcd for
2a resulted in decomposition. Therefore, 2a was con-
verted into the corresponding sulfone 19 by oxidation
with m-CPBA, and then the acid hydrolysis reaction of
19 was carried out at room temperature to provide the
corresponding diol derivative 20 quantitatively as shown
in Scheme 8. The major diastereomer of 2a was easily
separated, and it was similarly converted to optically
pure 20. The monofluorinated diol 20 thus obtained has
multifunctional groups; therefore, 20 seems to be a useful
fluorinated building block.
Con clu sion s
In this study, we investigated various effects of sup-
porting electrolytes, solvents, temperature, and molecular
structures on the diastereoselectivity in the electrochemi-
cal fluorination of sulfides having protected 1,2-diol
moieties. The results of our experiment definitely show
that the diastereoselectivity and yield were affected by
the electrolytic conditions, particularly, solvents and
protecting groups. We successfully carried out highly
diastereoselective anodic monofluorination of a sulfide
having a 2-spirocyclohexyl-1,3-dioxolanyl group, and the
fluorinated products were easily converted into mono-
fluorodiol derivative in good yield.
C
15H20O2S: C, 68.14; H, 7.62; S, 12.13. Found: C, 68.24; H,
7.48; S, 11.85.
Da ta for (R)-4-[[(p-ch lor op h en yl)th io]m eth yl]-2-sp ir o-
cycloh exyl-1,3-dioxolan e (1b): yield 84.2%; 1H NMR (CDCl3)
δ 7.33-7.24 (4H, m), 4.23-4.14 (1H, m), 4.10-3.71 (2H, m),
3.20-2.89 (2H, m), 1.60-1.26 (10H, m) ppm; 13C NMR (CDCl3)
δ 134.7, 131.2, 130.9, 129.0, 110.3, 74.3, 68.3, 37.6, 36.7, 35.0,
25.2, 24.1, 23.9 ppm; MS (m/z) 298 (M+), 141 (M+ - CH2SC6H4-
Cl); HRMS (m/z) calcd for
C15H19ClO2S 298.0794, found
298.0794.
Da ta for (R)-4-[[(p-n itr op h en yl)th io]m eth yl]-2-sp ir o-
cycloh exyl-1,3-dioxolan e (1c): yield 77.9%; 1H NMR (CDCl3)
δ 8.26-8.10 (2H, m), 7.52-7.36 (2H, m), 4.69-4.56 (1H, m),
4.48-4.23 (2H, m), 3.48-3.21 (2H, m), 1.66-1.37 (10H, m)
ppm; 13C NMR (CDCl3) δ 143.1, 141.8, 129.0, 126.4, 107.4, 73.8,
68.1, 37.2, 36.1, 25.3, 24.2 ppm; MS (m/z) 309 (M+), 141 (M+
- CH2SC6H4NO2); HRMS (m/z) calcd for C15H19NO4S 309.1035,
found 309.1035.
Exp er im en ta l Section
Gen er a l P r oced u r es. Et3N‚nHF (n ) 2-5) and Et4NF‚
nHF (n ) 3, 4) were obtained from a commercial supplier. They
are toxic and may cause serious burns if they come in contact
with unprotected skin. Et3N‚nHF (n ) 2, 3) and Et4NF‚3HF
are much less aggressive. However, proper safety precautions
should be taken at all times. It is therefore recommended that
rubber gloves be used. 1H NMR (270 MHz), 13C NMR (68 MHz),
and 19F NMR (254 MHz) spectra were determined using CDCl3
as a solvent. The chemical shift for 19F NMR is given in δ (ppm)
upfield from the peak for external trifluoroacetic acid. The
product yields were determined by 19F NMR using mono-
fluorobenzene as an internal standard material.
Data for (R)-4-[[(p-m eth oxyph en yl)th io)m eth yl]-2-spir o-
cycloh exyl-1,3-dioxolan e (1d): yield 96.1%; 1H NMR (CDCl3)
δ 7.39-7.36 (2H, m), 6.85-6.82 (2H, m), 4.20-4.13 (1H, m),
4.05 (1H, dd, J ) 8.1, 5.9 Hz), 3.79 (3H, s), 3.69 (1H, dd, J )
8.1, 5.9 Hz), 3.17-2.78 (2H, m), 1.61-1.38 (10H, m) ppm; 13
C
NMR (CDCl3) δ 159.0, 133.5, 125.3, 114.5, 109.9, 74.6, 68.4,
55.3, 39.3, 36.7, 35.1, 25.1, 24.0, 23.8 ppm; MS (m/z) 294 (M+),
155 (M+ - CH2SC6H4OCH3); HRMS (m/z) calcd for C16H22O3S
294.1290, found 294.1290.
Data for (R)-4-[flu or o(ph en ylth io)m eth yl]-2-spir ocyclo-
h exyl-1,3-d ioxola n e (2a ) (m or e p ola r d ia ster eom er ): 1H
NMR (CDCl3) δ 7.53-7.27 (5H, m), 5.72 (1H, dd, J ) 54.1, 5.4
Hz), 4.34-4.20 (1H, m), 4.07-3.70 (2H, m), 1.87-1.39 (10H,
m) ppm; 19F NMR (CDCl3) δ -80.12 (dd, J ) 54.6, 11.2 Hz)
ppm; 13C NMR (CDCl3) δ 132.8, 129.2, 128.6, 126.3, 110.8,
101.1 (d, J ) 222.0 Hz), 75.3 (d, J ) 27.3 Hz), 63.6 (d, J ) 2.8
Hz), 35.8, 34.6, 30.8, 25.3, 23.9 ppm; MS (m/z) 282 (M+), 141
(M+ - CHFSC6H5); HRMS (m/z) calcd for C15H19FO2S 282.1090,
found 282.1090.
Ma ter ia ls. The typical procedure for the preparation of
starting sulfide 1a is as follows. To a solution of (R)-(-)-3-
chloro-1,2-propanediol (0.92 mL, 11 mmol) and benzenethiol
(1.1 g, 10 mmol) in DMF (30 mL) was added potassium
carbonate (0.28 g, 20 mmol) at room temperature for 6 h. After
the reaction, water was added to the resulting solution. The
resulting solution was extracted repeatedly with ethyl acetate,
and the extracts were dried over MgSO4. The solution was
concentrated in vacuo, and the residue, 1,1-dimethoxycyclo-
hexane (2.02 g, 14 mmol) and p-toluenesulfonic acid mono-
hydrate (0.09 g, 0.5 mmol), was stirred at room temperature
for 1 h. After the reaction, water was added. The resulting
solution was extracted repeatedly with ethyl acetate, and the
extracts were dried over MgSO4. The extraction solvent was
removed by evaporation, and the remaining material was
subjected to column chromatography on silica gel (hexane:
EtOAc ) 9:1) to give 2.49 g (94.1% yield) of pure (R)-4-
[(phenylthio)methyl]-2-spirocyclohexyl-1,3-dioxolane (1a ).
Electr olysis. Constant-current electrolysis (10 mA/cm2) of
sulfide (1 mmol) was carried out at platinum electrodes (2 ×
2 cm2) in 10 mL of solvents containing 1.0 M fluoride salt using
Da ta for 2a (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.54-7.27 (5H, m), 5.62 (1H, dd, J ) 54.1, 7.0 Hz), 4.35-
4.21 (1H, m), 4.09-3.72 (2H, m), 1.67-1.40 (10H, m) ppm; 19
F
NMR (CDCl3) δ -79.52 (dd, J ) 54.5, 9.4 Hz) ppm; 13C NMR
(CDCl3) δ 132.7, 129.5, 128.8, 126.3, 110.0, 101.5 (d, J ) 222.0
Hz), 75.5 (d, J ) 27.3 Hz), 63.4 (d, J ) 2.8 Hz), 36.0, 34.7,
30.9, 25.1, 23.8 ppm; MS (m/z) 282 (M+), 141 (M+ - CHFSC6H5);
HRMS (m/z) calcd for C15H19FO2S 282.1090, found 282.1090.
Da ta for (R)-4-[flu or o[(p-ch lor op h en yl)th io]m eth yl]-
2-sp ir ocycloh exyl-1,3-d ioxola n e (2b ) (m or e p ola r d ia -
ster eom er ): 1H NMR (CDCl3) δ 7.35-7.25 (4H, m), 5.93 (1H,
1280 J . Org. Chem., Vol. 69, No. 4, 2004

Electrolytic Fluorination of Organic Compounds
dd, J ) 53.8, 3.0 Hz), 4.71-4.63 (1H, m), 4.50-4.31 (2H, m),
1.70-1.41 (10H, m) ppm; 19F NMR (CDCl3) δ -79.91 (dd, J )
53.6, 11.2 Hz) ppm; 13C NMR (CDCl3) δ 139.3, 131.2, 130.0,
128.1, 108.9, 101.1 (d, J ) 224.1 Hz), 74.5, 69.1, 38.5, 36.5,
25.1, 23.1 ppm; MS (m/z) 316 (M+), 141 (M+ - CHFSC6H4-
NO2); HRMS (m/z) calcd for C15H18ClFO2S 316.0700, found
316.0700.
3.64 (1H, m), 3.53-3.51 (2H, m), 3.37 (3H, s), 3.27 (3H, s) ppm;
19F NMR (CDCl3) δ -85.19 (dd, J ) 54.6, 16.8 Hz) ppm; 13C
NMR (CDCl3) δ 135.9, 130.0, 127.9, 126.3, 102.1, 79.7, 64.3,
56.0, 52.7 ppm; MS (m/z) 230 (M+), 109 (M+ - CHFCH-
(OCH3)CH2OCH3); HRMS (m/z) calcd for C11H15FO2S 230.0777,
found 230.0777.
Da ta for 1-[(p h en ylth io)m eth yl]tetr a h yd r ofu r a n (7):
yield 67.4%; 1H NMR (CDCl3) δ 7.38-7.13 (5H, m), 4.08-4.03
(1H, m), 3.94-3.72 (2H, m), 3.19-2.93 (2H, m), 1.96-1.86 (2H,
m), 1.72-1.65 (2H, m) ppm; 13C NMR (CDCl3) δ 136.2, 129.0,
128.7, 125.8, 77.5, 68.3, 38.9, 31.0, 25.8 ppm; MS (m/z) 194
(M+), 123 (M+ - CH2SC6H5); HRMS (m/z) calcd for C11H14OS
194.0765, found 194.0765.
Da ta for 1-[(p h en ylth io)flu or om eth yl]tetr a h yd r ofu r a n
(8) (m or e p ola r d ia ster eom er ): 1H NMR (CDCl3) δ 7.38-
7.23 (5H, m), 5.78 (1H, dd, J ) 55.5, 4.1 Hz,), 4.29-4.18 (1H,
m), 3.96-3.78 (2H, m), 1.99-1.88 (2H, m), 1.71-1.66 (2H, m)
ppm; 19F NMR (CDCl3) δ -78.19 (dd, J ) 55.6, 14.7 Hz) ppm;
13C NMR (CDCl3) δ 136.1, 129.1, 128.7, 125.9, 103.3 (d, J )
223.1 Hz), 79.3, 68.9, 31.2, 23.7 ppm; MS (m/z) 212 (M+), 141
(M+ - CHFSC6H5); HRMS (m/z) calcd for C11H13FOS 212.0671,
found 212.0671.
Da ta for 2b (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.37-7.26 (4H, m), 5.88 (1H, dd, J ) 53.0, 4.7 Hz), 4.73-
4.63 (1H, m), 4.51-4.33 (2H, m), 1.70-1.42 (10H, m) ppm;19F
NMR (CDCl3) δ -79.36 (dd, J ) 53.6, 9.1 Hz) ppm; 13C NMR
(CDCl3) δ 139.2, 131.3, 130.1, 128.0, 108.9, 101.3 (d, J ) 224.0
Hz), 74.6, 69.6, 38.4, 36.5, 25.2, 23.1 ppm; MS (m/z) 316 (M+),
141 (M+ - CHFSC6H4NO2); HRMS (m/z) calcd for C15H18
ClFO2S 316.0700, found 316.0700.
-
Da ta for (R)-4-[flu or o[(p-n itr op h en yl)th io]m eth yl]-2-
sp ir ocycloh exyl-1,3-d ioxola n e (2c) (m or e p ola r d ia -
ster eom er ): 1H NMR (CDCl3) δ 8.20-8.17 (2H, m), 7.64-
7.60 (2H, m), 5.87 (1H, dd, J ) 54.6, 5.4 Hz), 4.41-4.38 (1H,
m), 4.15-4.02 (2H, m), 1.69-1.40 (10H, m) ppm; 19F NMR
(CDCl3) δ -79.08 (dd, J ) 46.3, 9.2 Hz) ppm; 13C NMR (CDCl3)
δ 143.6, 141.1, 129.8, 126.4, 109.3, 101.1 (d, J ) 223.1 Hz),
74.7, 68.1, 38.2, 36.2, 25.7, 23.1 ppm; MS (m/z) 327 (M+), 141
(M+ - CHFSC6H4NO2); HRMS (m/z) calcd for C15H18FNO4S
327.0941, found 327.0941.
Da ta for 2c (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 8.19-8.16 (2H, m), 7.61-7.55 (2H, m), 5.82 (1H, dd, J ) 54.7,
6.2 Hz), 4.41-4.39 (1H, m), 4.15-4.02 (2H, m), 1.69-1.40
(10H, m) ppm; 19F NMR (CDCl3) δ -82.59 (dd, J ) 55.4, 13.0
Hz) ppm; 13C NMR (CDCl3) δ 143.8, 141.2, 129.9, 126.4, 109.3,
101.0 (d, J ) 223.1 Hz), 74.5, 68.1, 38.3, 36.1, 25.6, 23.3 ppm;
MS (m/z) 327 (M+), 141 (M+ - CHFSC6H4NO2); HRMS (m/z)
calcd for C15H18FNO4S 327.0941, found 327.0941.
Da ta for 2-m eth oxyp r op yl p h en yl su lfid e (3): 1H NMR
(CDCl3) δ 7.37-7.13 (5H, m), 3.53-3.44 (1H, m), 3.34 (3H, s),
3.18-2.83 (1H, m), 1.26 (3H, d, J ) 6.3 Hz) ppm; 13C NMR
(CDCl3) δ 133.6, 129.1, 128.8, 125.9, 75.9, 55.5, 37.7, 19.0 ppm;
MS (m/z) 182 (M+), 123 (M+ - CH(OCH3)CH3); HRMS (m/z)
calcd for C10H14OS 182.0765, found 182.0770.
Da ta for 2-m eth oxy-1-flu or op r op yl p h en yl su lfid e (4)
(m or e p ola r d ia ster eom er ): 1H NMR (CDCl3) δ 7.51-7.26
(5H, m), 5.82 (1H, dd, J ) 51.3, 3.0 Hz), 3.63-3.55 (1H, m),
3.41 (3H, s), 1.26 (3H, d, J ) 6.3 Hz) ppm; 19F NMR (CDCl3)
δ -75.76 (dd, J ) 54.2, 12.9 Hz) ppm; 13C NMR (CDCl3) δ
134.3, 130.3, 128.6, 126.3, 108.1, 74.6, 51.4, 14.0 ppm; MS (m/
z) 200 (M+), 109 (M+ -CHFCH(OCH3)CH3); HRMS (m/z) calcd
for C10H13FOS 200.0671, found 200.0671.
Da ta for 4 (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.51-7.26 (5H, m), 5.68 (1H, dd, J ) 50.1, 5.5 Hz), 3.63-
3.55 (1H, m), 3.38 (3H, s), 1.25 (3H, d, J ) 6.3 Hz) ppm; 19F
NMR (CDCl3) δ -80.68 (dd, J ) 55.6, 14.3 Hz) ppm; 13C NMR
(CDCl3) δ 134.1, 130.1, 128.3, 126.0, 107.9, 74.2, 51.2, 13.8
ppm; MS (m/z) 200 (M+), 109 (M+ - CHFCH(OCH3)CH3);
HRMS (m/z) calcd for C10H13FOS 200.0671, found 200.0671.
Da ta for 2,3-d im eth oxyp r op yl p h en yl su lfid e (5): 1H
NMR (CDCl3) δ 7.39-7.18 (5H, m), 3.55-3.49 (2H, m), 3.52-
3.45 (1H, m), 3.41 (3H, s), 3.34 (3H, s), 3.12-3.10 (2H, m) ppm;
13C NMR (CDCl3) δ 136.8, 129.2, 128.8, 126.0, 79.1, 72.7, 59.3,
57.7, 34.5 ppm; MS (m/z) 212 (M+), 123 (M+ - CH(OCH3)CH2-
(OCH3)); HRMS (m/z) calcd for C11H16O2S 212.0871, found
212.0871.
Da ta for 8 (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.38-7.24 (5H, m), 5.66 (1H, dd, J ) 54.6, 5.4 Hz), 4.29-
4.18 (1H, m), 4.01-3.81 (2H, m), 1.98-1.86 (2H, m), 1.74-
1.70 (2H, m) ppm; 19F NMR (CDCl3) δ -80.07 (dd, J ) 54.5,
16.5 Hz) ppm; 13C NMR (CDCl3) δ 136.2, 129.1, 128.8, 125.9,
103.4 (d, J ) 223.1 Hz), 79.4, 69.1, 31.1, 24.0 ppm; MS (m/z)
212 (M+), 141 (M+ - CHFSC6H5); HRMS (m/z) calcd for
C
11H13FOS 212.0671, found 212.0671.
Da ta for 4-[(P h en ylth io)m eth yl]-1,3-d ioxola n e (9): 1H
NMR (CDCl3) δ 7.40-7.21 (5H, m), 5.06 (2H, s), 4.22-4.17 (1H,
m), 4.00-3.68 (2H, m), 3.27-2.92 (2H, m) ppm; 13C NMR
(CDCl3) δ 134.1, 129.7, 128.2, 126.3, 97.6, 75.6, 68.3, 39.3 ppm;
MS (m/z) 196 (M+), 123 (M+ - CH2SC6H5); HRMS (m/z) calcd
for C10H12O2S 196.0558, found 196.0558.
Da ta for 4-[flu or o(p h en ylth io)m eth yl]-1,3-d ioxola n e
(10) (m or e p ola r d ia ster eom er ): 1H NMR (CDCl3) δ 7.40-
7.18 (5H, m), 5.59 (1H, dd, J ) 54.6, 5.7 Hz), 5.09 (2H, s), 4.72-
4.59 (1H, m), 4.41-4.28 (2H, m) ppm; 19F NMR (CDCl3) δ
-81.31 (dd, J ) 54.5, 13.0 Hz) ppm; 13C NMR (CDCl3) δ 135.6,
128.7, 126.6, 124.9, 100.4, 97.9, 90.0, 72.1 ppm; MS (m/z) 214
(M+), 141 (M+ - CHFSC6H5); HRMS (m/z) calcd for C10H11
FO2S 214.0464, found 214.0464.
-
Da ta for 10 (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.43-7.22 (5H, m), 5.51 (1H, dd, J ) 54.2, 7.0 Hz), 5.11 (2H,
s), 4.75-4.60 (1H, m), 4.40-4.25 (2H, m) ppm; 19F NMR
(CDCl3) δ -79.16 (dd, J ) 53.6, 13.0 Hz) ppm; 13C NMR
(CDCl3) δ 135.1, 127.9, 126.8, 124.7, 100.7, 98.1, 90.1, 71.7
ppm; MS (m/z) 214 (M+), 141 (M+ - CHFSC6H5); HRMS (m/z)
calcd for C10H11FO2S 214.0464, found 214.0464.
Da ta for (R)-4-[(p h en ylth io)m eth yl]-2,2-d im eth yl-1,3-
1
d ioxola n e (11): yield 86.3%; H NMR (CDCl3) δ 7.39-7.19
(5H, m), 4.26-4.14 (1H, m), 4.05-3.72 (2H, m), 3.24-2.90 (2H,
m), 1.43 (3H, s), 1.33 (3H, s) ppm; 13C NMR (CDCl3) δ 136.6,
130.0, 129.4, 126.8, 110.0, 75.1, 69.2, 27.5, 25.8 ppm; MS (m/
z) 224 (M+), 123 (M+ - CH2SC6H5); HRMS (m/z) calcd for
C
12H16O2S 224.0871, found 224.0871.
Data for (R)-4-[flu or o(ph en ylth io)m eth yl]-2,2-dim eth yl-
1,3-d ioxola n e (12) (m or e p ola r d ia ster eom er ): 1H NMR
(CDCl3) δ 7.57-7.30 (5H, m), 5.71 (1H, dd, J ) 54.1, 5.7 Hz),
4.38-4.28 (1H, m), 4.11-3.99 (2H, m), 1.48 (3H, s), 1.37 (3H,
s) ppm; 19F NMR (CDCl3) δ -79.55 (dd, J ) 54.5, 11.2 Hz)
ppm; 13C NMR (CDCl3) δ 132.6, 131.7, 129.0, 128.3, 110.4,
101.4 (d, J ) 222.0 Hz), 75.8 (d, J ) 27.3 Hz), 65.7 (d, J ) 2.8
Hz), 26.4, 25.2 ppm; MS (m/z) 242 (M+), 133 (M+ - SC6H5);
HRMS (m/z) calcd for C12H15FO2S 242.0777, found 242.0777.
Da ta for 12 (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.54-7.32 (5H, m), 5.63 (1H, dd, J ) 54.0, 7.0 Hz), 4.39-
4.28 (1H, m), 4.14-3.93 (2H, m), 1.48 (3H, s), 1.37 (3H, s) ppm;
19F NMR (CDCl3) δ -79.00 (dd, J ) 53.6, 11.2 Hz) ppm; 13C
NMR (CDCl3) δ 132.6, 131.3, 129.1, 128.3, 110.8, 101.3 (d, J
Da ta for 2,3-d im eth oxy-1-flu or op r op yl p h en yl su lfid e
(6) (m or e p ola r d ia ster eom er ): 1H NMR (CDCl3) δ 7.41-
7.30 (5H, m), 5.94 (1H, dd, J ) 54.0, 3.0 Hz), 3.81-3.73 (1H,
m), 3.51-3.47 (2H, m), 3.41 (3H, s), 3.31 (3H, s) ppm; 19F NMR
(CDCl3) δ -74.82 (dd, J ) 53.6, 13.0 Hz) ppm; 13C NMR
(CDCl3) δ 135.7, 129.8, 127.6, 126.0, 101.3, 79.3, 64.1, 55.7,
52.4 ppm; MS (m/z) 230 (M+), 109 (M+ - CHFCH(OCH3)CH2
OCH3); HRMS (m/z) calcd for C11H15FO2S 230.0777, found
230.0777.
Da ta for 6 (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.42-7.26 (5H, m), 5.90 (1H, dd, J ) 54.3, 4.3 Hz), 3.72-
J . Org. Chem, Vol. 69, No. 4, 2004 1281

Suzuki and Fuchigami
) 224.8 Hz), 76.4 (d, J ) 22.3 Hz), 66.0 (d, J ) 2.2 Hz), 26.5,
25.4 ppm; MS (m/z) 242 (M+), 133 (M+ - SC6H5); HRMS (m/z)
calcd for C12H15FO2S: 242.0777, found 242.0777.
(CDCl3) δ -85.32 (dd, J ) 52.4, 12.9 Hz) ppm; 13C NMR
(CDCl3) δ 153.6, 136.3, 130.6, 129.2, 129.0, 99.3 (d, J ) 225.4
Hz), 75.4 (d, J ) 26.2 Hz), 64.8 (d, J ) 3.3 Hz) ppm; MS (m/z)
273 (M+), 186 (M+ - CH(OC(dO)O)CH2-); HRMS (m/z) calcd
for C10H8FNO5S 273.0107, found 273.0107.
Da ta for (R)-4-[(p h en ylth io)m eth yl]-2-(2-sp ir oa d a m a n -
tyl)-1,3-d ioxola n e (13): yield 54.6%; 1H NMR (CDCl3) δ
7.39-7.16 (5H, m), 4.27-4.20 (1H, m), 4.09-3.73 (2H, m),
3.27-2.88 (2H, m), 1.98-1.57 (14H, m) ppm; 13C NMR (CDCl3)
δ 135.5, 129.7, 128.9, 126.3, 112.6, 74.5, 68.3, 38.3, 37.6, 34.8,
27.1, 26.9 ppm; MS (m/z) 316 (M+), 123 (M+ - CH2SC6H5);
HRMS (m/z) calcd for C19H24O2S 316.1497, found 316.1497.
Da ta for (R)-4-[flu or o(p h en ylth io)m eth yl]-2-(2-sp ir o-
a d a m a n t yl)-1,3-d ioxola n e (14) (m or e p ola r d ia st er eo-
m er ): 1H NMR (CDCl3) δ 7.50-7.27 (5H, m), 5.61 (1H, dd, J
) 54.0, 7.0 Hz), 4.39-4.28 (1H, m), 4.14-3.94 (2H, m), 2.00-
1.61 (14H, m) ppm; 19F NMR (CDCl3) δ -79.68 (dd, J ) 53.6,
11.2 Hz) ppm; 13C NMR (CDCl3) δ 134.4, 130.3, 127.7, 126.3,
112.5, 101.1, 77.3, 60.6, 38.1, 34.7, 26.2, 25.9 ppm; MS (m/z)
334 (M+), 123 (M+ - CH2SC6H5); HRMS (m/z) calcd for
Da ta for (1R, 2S)-4-[flu or o(p h en ylsu lfon yl)m eth yl]-2-
sp ir ocycloh exyl-1,3-d ioxola n e (19): [R]23 -8.0 (c 0.4,
D
1
CHCl3); H NMR (CDCl3) δ 7.91-7.55 (5H, m), 5.21 (1H, dd,
J ) 48.3, 9.2 Hz), 4.41-4.23 (1H, m), 4.13-4.10 (2H, m), 1.62-
1.38 (10H, m) ppm; 19F NMR (CDCl3) δ -117.66 (dd, J ) 46.0,
20.3 Hz) ppm; 13C NMR (CDCl3) δ 136.5, 132.1, 130.8, 129.6,
110.9, 100.1(d, J ) 224.9 Hz), 71.5 (d, J ) 22.7 Hz), 63.9 (d, J
) 5.2 Hz), 35.7, 34.5, 25.0, 23.9, 23.8 ppm; MS (m/z) 314 (M+),
141 (M+ - CHFSO2C6H5); HRMS (m/z) calcd for C15H19FO4S
314.0988, found 314.0988. Anal. Calcd for C15H19FO4S: C,
57.31; H, 6.09; F, 6.04; S; 10.20. Found: C, 57.35; H, 5.97; F,
6.12; S; 10.02.
Hyd r olysis of F lu or in a ted Su lfid e 2a to th e Cor r e-
sp on d in g Diol 20. A mixture of fluoroalkylated dioxolane 2a
(282 mg, 1.0 mmol), methanol (2 mL), and concd hydrochloric
acid (1 mL) was stirred under reflux for 1 h (the complete
conversion of 2a was checked by 19F NMR). Methanol was
removed on a rotary evaporator, and water was then added.
The resulting solution was extracted repeatedly with ethyl
acetate, and the extraction solvent was removed by evapora-
tion. The remaining residue was subjected to column chroma-
tography on silica gel (hexane:EtOAc ) 4:1) to give 0.21 g
(91.1% yield) of pure 20.
C
19H23FO2S 334.1403, found 334.1403.
Da ta for 14 (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.49-7.26 (5H, m), 5.68 (1H, dd, J ) 54.1, 7.2 Hz), 4.39-
4.28 (1H, m), 4.14-3.94 (2H, m), 2.00-1.61 (14H, m) ppm; 19
F
NMR (CDCl3) δ -79.01 (dd, J ) 53.6, 11.2 Hz) ppm; 13C NMR
(CDCl3) δ 134.6, 130.0, 127.8, 126.3, 112.5, 102.1, 77.8, 60.4,
38.2, 34.7, 26.3, 26.1 ppm; MS (m/z) 334 (M+), 123 (M+
-
CH2SC6H5); HRMS (m/z) calcd for C19H23FO2S 334.1403, found
334.1403.
Da t a for 4-[(P h en ylt h io)m et h yl]-1,3-d ioxola n -2-on e
(15): yield 81.0%; 1H NMR (CDCl3) δ 7.44-7.26 (5H, m), 4.76-
4.74 (1H, m), 4.56-4.49 (1H, m), 4.29-4.23 (1H, m), 3.43-
3.03 (2H, m) ppm; 13C NMR (CDCl3) δ 155.3, 133.8, 131.1,
129.5, 127.8, 74.7, 68.6, 37.1 ppm; MS (m/z) 210 (M+), 123 (M+
- CH(OC(dO)O)CH2-); HRMS (m/z) calcd for C10H10O3S
210.0351, found 210.0358.
Da ta for (1R,2S)-3-flu or o-3-(p h en ylsu lfon yl)-1,2-p r o-
1
p a n ed iol (20): [R]22 +36.6 (c 0.5, CHCl3); H NMR (CDCl3)
D
δ 7.99-7.60 (5H, m), 5.24 (1H, dd, J ) 46.4, 8.1 Hz), 4.26-
4.20 (1H, m), 3.93-3.78 (2H, m), 3.48 (1H, br), 2.64 (1H, br)
ppm; 19F NMR (CDCl3) δ -117.66 (dd, J ) 46.0, 20.3 Hz) ppm;
13C NMR (CDCl3) δ 136.5, 132.1, 130.8, 129.6, 110.9, 100.1 (d,
J ) 224.9 Hz), 71.5 (d, J ) 22.7 Hz), 63.9 (d, J ) 5.2 Hz),
35.7, 34.5, 25.0, 23.9, 23.8 ppm; MS (m/z) 234 (M+); HRMS
(m/z) calcd for C9H11FO4S 234.0362, found 234.0362, found
234.0364. Anal. Calcd for C9H11FO4S: C, 46.15; H, 4.73; F,
8.11; S; 13.69. Found: C, 46.28; H, 4.79; F, 7.95; S; 13.95.
Da ta for 4-[flu or o(p h en ylth io)m eth yl]-1,3-d ioxola n -2-
on e (16) (m or e m ola r d ia ster eom er ): 1H NMR (CDCl3) δ
7.54-7.35 (5H, m), 5.90 (dd, J ) 53.5, 2.7 Hz), 5.00-4.91 (1H,
m), 4.56-4.36 (2H, m) ppm; 19F NMR (CDCl3) δ -88.96 (dd, J
) 53.6, 16.8 Hz) ppm; 13C NMR (CDCl3) δ 153.6, 136.3, 130.6,
129.2, 129.0, 99.3 (d, J ) 225.4 Hz), 75.4 (d, J ) 26.2 Hz),
64.8 (d, J ) 3.3 Hz) ppm; MS (m/z) 228 (M+), 141 (M+
-
Ch em ica l F lu or in a t ion Usin g N-F lu or op yr id in iu m
Sa lts. To a solution of 1a (282.0 mg, 1.0 mmol) in dry solvent
(MeCN, CH2Cl2) (2 mL) were added N-fluoropyridinium salts
A-C (2 equiv), and the resulting solution was stirred under
reflux in a nitrogen atmosphere for 12 h.
CH(OC(dO)O)CH2-); HRMS (m/z) calcd for C10H9FO3S
228.0256, found 228.0252.
Da ta for 16 (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 7.55-7.35 (5H, m), 5.76 (dd, J ) 51.7, 5.9 Hz), 4.92-4.80
(1H, m), 4.57-4.38 (2H, m) ppm; 19F NMR (CDCl3) δ -83.73
(dd, J ) 51.8, 13.0 Hz) ppm; 13C NMR (CDCl3) δ 153.8, 133.3,
133.1, 129.4, 129.2, 99.6 (d, J ) 226.5 Hz), 75.7 (d, J ) 25.1
Ch em ica l F lu or in a tion Usin g Selectflu or . To a solution
of 1a (282.0 mg, 1.0 mmol) in dry MeCN (4 mL) was added
selectfluor (3 equiv), and the resulting solution was stirred at
20 °C in a nitrogen atmosphere for 2 h.
Hz), 65.6 (d, J ) 1.7 Hz) ppm; MS (m/z) 228 (M+), 141 (M+
-
CH(OC(dO)O)CH2-); HRMS (m/z) calcd for C10H9FO3S
228.0256, found 228.0252.
X-r a y Cr ysta llogr a p h y. X-ray diffraction with graphite-
monochromated Mo KR radiation (λ ) 0.71069 Å) at -60 ( 1
°C to a maximum 2θ value of 55.0°. Crystal data for 18:
Da ta for 4-[[(p-n itr op h en yl)th io]m eth yl]-1,3-d ioxola n -
1
2-on e (17): yield 66.7%; H NMR (CDCl3) δ 8.21-8.14 (2H,
C
10H8O5NSF, fw ) 273.24, monoclinic, space group P21/n (No.
m), 7.49-7.23 (2H, m),4.96-4.86 (1H, m), 4.63-4.57 (1H, m),
4.35-4.29 (1H, m), 3.52-3.27 (2H, m) ppm; 13C NMR (CDCl3)
δ 128.0, 124.3, 131.1, 74.0, 68.2, 35.4 ppm; MS (m/z) 255 (M+),
168 (M+ - CH(OC(dO)O)CH2-); HRMS (m/z) calcd for C10H9-
NO5S 255.0211, found 255.0197.
14), a ) 10.085(4) Å, b ) 20.080(7) Å, c ) 5.430(2) Å, â )
90.23(2)°, V ) 1099.6(6) Å3, Z ) 4, Dcalcd ) 1.650 g/cm3, µ )
3.22 cm-1
.
Ack n ow led gm en t. We thank Prof. M. Akita of the
Tokyo Institute of Technology for X-ray analysis. We
also thank Prof. B.-J . Wang of the National Tsin Hua
University and Prof. T. Yamazaki of the Tokyo Univer-
sity of Agriculture and Technology for their valuable
suggestions.
Da ta for 4-[flu or o[(p-n itr op h en yl)th io]m eth yl]-1,3-d i-
oxola n -2-on e (18) (m or e m ola r d ia ster eom er ): 1H NMR
(CDCl3) δ 8.28-8.24 (2H, m), 7.75-7.68 (2H, m), 6.08 (dd, J
) 54.0, 2.9 Hz), 5.01-4.96 (1H, m), 4.66-4.57 (2H, m) ppm;
19F NMR (CDCl3) δ -88.78 (dd, J ) 54.2, 15.6 Hz) ppm; 13C
NMR (CDCl3) δ 153.8, 133.3, 133.1, 129.4, 129.2, 99.6 (d, J )
226.5 Hz), 75.7 (d, J ) 25.1 Hz), 65.6 (d, J ) 1.7 Hz) ppm; MS
(m/z) 273 (M+), 186 (M+ - CH(OC(dO)O)CH2-); HRMS (m/z)
calcd for C10H8FNO5S 273.0107, found 273.0107. Anal. Calcd
for C10H8FNO5S: C, 43.96; H, 2.95; F, 6.95; N, 5.13; S, 11.74.
Found: C, 43.89; H, 3.16; F, 6.77; N, 5.00; S, 11.74.
Su p p or tin g In for m a tion Ava ila ble: 1H NMR spectra of
1b-d , 2a -c, and 3-17 and 19F NMR spectra of 2a -c, 4, 6, 8,
12, 14, and 16 (PDF). X-ray crystal structure of compound 18.
This material is available free of charge via the Internet at
http://pubs.acs.org.
Da ta for 18 (less p ola r d ia ster eom er ): 1H NMR (CDCl3)
δ 8.25-8.22 (2H, m), 7.69-7.66 (2H, m), 5.96 (dd, J ) 52.5,
4.3 Hz), 5.04-5.02 (1H, m), 4.65-4.47 (2H, m) ppm; 19F NMR
J O035291J
1282 J . Org. Chem., Vol. 69, No. 4, 2004