Synthesis of substituted tetrahydrofurans via intermolecular reactions of γ-chlorocarbanions of 3-substituted 3-chloro-propylphenyl sulfones with aldehydes

Article abstract of DOI:10.1016/j.tet.2010.02.006

Carbanions of 3-substituted-3-chloropropyl phenyl sulfones add to carbonyl groups of aldehydes to produce aldol type adducts that undergo 1,5-intramolecular substitution giving 2,3,5-trisubstituted tetrahydrofurans. The effect of substituents in the 3-pos

Full text of DOI:10.1016/j.tet.2010.02.006

Tetrahedron 66 (2010) 3378–3385
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Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Synthesis of substituted tetrahydrofurans via intermolecular reactions
of
g-chlorocarbanions of 3-substituted 3-chloro-propylphenyl sulfones
with aldehydes
,
b
,
y
a
a
a,
*
Agnieszka Brandt a , Anna Wojtasiewicz , Marcin Sniezek , Mieczys1aw Ma˛kosza
´
_
a Institute of Organic Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, PO Box 58, 01-224 Warsaw 42, Poland
b Trainee student from Department Chemie und Biochemie, Ludwig-Maximilians-Universitaet Muenchen Butenandtstr. 5-13 (Haus F), D-81377 Muenchen, Germany
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 27 July 2009
Received in revised form 14 January 2010
Accepted 1 February 2010
Available online 10 February 2010
Carbanions of 3-substituted-3-chloropropyl phenyl sulfones add to carbonyl groups of aldehydes to
produce aldol type adducts that undergo 1,5-intramolecular substitution giving 2,3,5-trisubstituted
tetrahydrofurans. The effect of substituents in the 3-position of these sulfones on the relative rates of
1,3-intramolecular substitution of the corresponding
addition are disclosed.
g
-chlorocarbanions and their intramolecular
Ó 2010 Elsevier Ltd. All rights reserved.
Dedicated to Professor Vladimir Minkin to
celebrate his 75th birthday
Keywords:
Carbanions
Aldol reaction
Cyclization
R
Z
Y
R
Y
Z
-
1. Introduction
R
Y
Z
Y
Cl
In our previous papers, we have shown that g-halocarbanions
B
generated from 3-chloropropyl aryl sulfones, 4-chlorobutyronitrile
and tert-butyl 4-chlorobutyrate, in spite of fast intramolecular
substitution leading to cyclopropanes, can be trapped by active
Cl
Cl
electrophilic partners. Thus, generation of such g-halocarbanions in
the presence of aldehydes results in formation of the intermediate
anionic aldol-type adducts that undergo 1,5-intramolecular sub-
stitution producing substituted tetrahydrofurans.1 Similar reactions
Y
Y = SO2Ar, CN, COOtBu, COPh; Z = O, N EWG, CH EWG
of g
-halocarbanions with electron-deficient imines2 and Michael
acceptors3 give rise to substituted pyrrolidines and cyclopentanes.
This simple and valuable method of synthesis of hetero- and car-
bocyclic five-membered rings is severely limited because of a high
rate of 1,3-intramolecular substitution in the 3-chlorocarbanion. As
a result, the desired reactions proceed only with highly active
electrophilic partners (Scheme 1).
In order to expand the scope of the reaction we have studied the
effect of substituents in the chain of the g-halocarbanions on the
reaction course. In our early paper, we reported that a phenyl group
Scheme 1.
in position 2- of 4-chlorobutyronitrile favours intramolecular
1,3-substitution leading to the cyclopropane at the expense of in-
termolecular addition.1a On the other hand, preliminary observa-
tions indicated that a methyl group in position 3- of 3-chloropropyl
phenyl sulfone substantially decelerates the 1,3-intramolecular
substitution, so the respective
intermolecular reactions.1c In this paper, we report that substituents
in position of the -halocarbanion generated from 3-chloro-
g-halocarbanion can enter readily into
g
g
3-phenylpropyl phenyl sulfone 1, 3-chlorobutyl phenyl sulfone 2 and
3-chloro-3-phenylthiopropyl phenyl sulfone 3, affect the rates of
1,3-intramolecular substitution and, as a consequence, there is
* Corresponding author. Fax: þ48 22 6326681; e-mail address: icho-s@icho.edu.pl.
y
Fax: 49 89 2180 77717.
0040-4020/$ – see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2010.02.006

A. Brandt et al. / Tetrahedron 66 (2010) 3378–3385
3379
R
competition between this reaction and intermolecular addition to
aldehydes leading to tetrahydrofurans.
K+
R
R
t-BuOK
THF or toluene
-
Cl
SO2Ph
Cl
SO2Ph
A phenyl group in position 3- of 3-chloro-3-phenylpropyl phenyl
sulfone 1 can affect rates of intramolecular substitution in two
opposite ways. Since the halogen in 1 occupies the benzylic position,
its nucleophilic substitution can be accelerated as compared to the
parent 3-chloropropyl phenyl sulfone. On the other hand, sub-
stitution of the halogen in 1 proceeds at the secondary carbon atom,
so it should be a slower process, decelerated as compared with that
at the primary carbon. A methyl group in position 3- of 3-chlorobutyl
phenyl sulfone 2 and phenylsulfide group in position 3- of (3-chloro-
3-phenylthio)propylphenyl sulfone 3 should decelerate 1,3-intra-
molecular nucleophilic substitution of chlorine in the corresponding
carbanions due to electron-donating and steric effects.
In the literature, we have found only two examples of reactions
of similar carbanions. 3-Bromo-3-phenylpropyl phenyl sulfone,
synthesized via bromination of 3-phenylpropyl phenyl sulfone with
NBS, when treated with strong base was converted into 1-phenyl-
sulfonyl-2-phenylcyclopropane (cis and trans isomers).4 Similarly,
base-induced reaction of [1-chloro-3-(N-methyl-S-phenyl-
sulfonimidoyl)propyl]benzene gave the expected di-substituted
cyclopropane.5 No attempts of intermolecular reaction of the in-
SO2Ph
R = Ph (1), CH3 (2), SPh (3)
1a - 3a
Scheme 5.
Table 1
Reactant
Yield [%]
(s1/2)
In THF
84
In toluene
98
3-Chloro-3-phenylpropyl phenyl
sulfone 1
3-Chlorobutylphenyl sulfone 2
(3-Chloro-3-phenylthio)propylphenyl
sulfone 3
less than 1 s
71
74
71
96
60 s
120 sa
a
Reaction in toluene at 0 ꢁC.
As we expected, intramolecular substitution in carbanion of 1
proceeds with a rate similar to that of 3-chloropropyl phenyl sulfone,
whereas cyclization of the carbanions of 2 and 3 is much slower.
When a solution of 1 and benzaldehyde in THF was treated at low
temperature with t-BuOK, the expected 2,5-diphenyl-3-phenyl-
sulfonyl tetrahydrofuran 1b was produced as a mixture of two
diastereoisomers. Cyclopropane 1a was also formed but in small
quantities.
On the other hands the reaction of 2 with benzaldehyde under
these conditions gave the expected 5-methyl-2-phenyl-3-phenyl-
sulfonyl tetrahydrofuran 2b (also a mixture of two diastereoisomers)
only in moderate yield, along with cyclopropane 2a.
termediate g-halocarbanions with aldehydes or other electrophilic
partners were reported in these papers.
3-Chloro-3-phenylpropyl phenyl sulfone was obtained via
reaction of phenylsulfinic acid with 3-(trimethyl-ammonium)-
1-phenylpropanone iodide,6 borohydride reduction of the pro-
duced ketosulfone and conversion of the alcohol into chloride 1 by
reaction with hydrochloric acid (Scheme 2).
O
Cl
Thisisbecausethemethyl group inposition3 of 2ꢀ deceleratesnot
only 1,3-intramolecular substitution, but also 1,5-intramolecular
substitution in the aldol-type adduct. Thus, due to reversibility of the
addition, the cyclopropane was formed in substantial amounts. For-
mation of 2b was the main process when the reaction was carried out
in toluene. It seems that strong association of the potassium cations
with the negatively charged oxygen of the aldol type adduct favours
the addition and consequently formation of tetrahydrofurans.
This effect is even stronger in the reactions of 3. Treatment of
a solution of 3 and benzaldehyde in THF with t-BuOK gave mainly
the cyclopropane 3a, whereas in toluene the desired tetrahydro-
furan 3b was obtained, although in moderate yield.
O
PhSO2H
40%
1. LiBH4, 80%
2. HCl, 70%
+
Ph
Ph
SO2Ph
Ph
SO2Ph
NMe3
I
1
Scheme 2.
3-Chlorobutyl phenyl sulfone 2 was obtained from the reaction
of methyl-vinyl ketone with sodium phenylsulfinate followed by
reduction of the ketosulfone with sodium borohydride and
the Appel reaction of the alcohol with PPh3 and CCl4 (Scheme 3).
3-Chloro-3-phenylthiopropyl phenyl sulfone 3 was obtained as
shown in Scheme 4.
O
O
Cl
PhSO2Na
91%
1. NaBH4, 96%
Under these standard conditions: t-BuOK in THF or toluene
a series of reactions between 1, 2 and 3 and aromatic aldehydes
were carried out giving the expected 2,3,5-trisubstituted tetrahy-
drofurans, usually in good yields (Table 3). Moderate yields of tet-
2. CCl4, PPh3, 75%
SO2Ph
SO2Ph
2
Scheme 3.
rahydrofurans obtained from
3 are mostly because these
Cl
compounds, being in fact monothioacetals, are of moderate stabil-
ity, so we encountered difficulties due to decomposition during
chromatographic purification. In order to avoid these problems the
crude products 3b–e were oxidized with MCPBA to disulfones 4b–e
that were more stable and could be purified. The same conditions
were also used for reaction without aldehyde and trans-cyclopro-
pane 4a was obtained in 63% yield. The results of these experiments
are shown in Table 2.
PhSH
Et3N
96%
NCS
CCl4
95%
Cl
SO2Ph
PhS
SO2Ph
PhS
SO2Ph
3
Scheme 4.
All these carbanion precursors 1, 2 and 3, when treated with
t-BuOK in THF are deprotonated, subsequent intramolecular 1,3-
substitution gave the expected disubstituted cyclopropanes 1a, 1b
and 1c in good yields. Even better yields were obtained when the
reaction was carried out in toluene. Substituents in the cyclopro-
pane rings of 1a, 1b and 1c are always trans and this was estab-
lished on the basis of 1H NMR spectra, 1D NOE experiments and
comparison with literature data.
In order to estimate the effect of substituents on the rate of
intramolecular substitution solutions of 1, 2 and 3 in THF and
toluene at low temperature were treated with t-BuOK and after
a short time the mixtures were quenched with an aqueous solution
of NH4Cl (Scheme 5). On the basis of such experiments, the time of
Table 2
Comparison of the reactions of carbanions 1, 2 and 3 with benzaldehyde under
various conditions
Reactanta
Yield [%]
In THF
1b–3b
In toluene
1a–3a
1b–3b
1a–3a
1
2
3
68
60
d
10
90
78
42
d
16
15
80b
Tracesb
a
half-conversion (
pane was estimated. The results are presented in Table 1.
s1/2) of the g-chlorocarbanion into the cyclopro-
Sulfones identified by numbers 1–3 as shown in Scheme 6.
Yield after oxidation by MCPBA.
b

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A. Brandt et al. / Tetrahedron 66 (2010) 3378–3385
Table 3
isomers with substituents in positions 2,3- and 2,5- in relation trans
(Table 3).
Results of the reactions of carbanions 1, 2 and 3 with aldehydes as in Scheme 6
Reactanta R in aldehyde Tetrahydrofuran
Cyclopropane
In most of the cases the diastereoisomers of the obtained
tetrahydrofurans were separated and the relation (cis- or trans-)
of 2-aryl and 5-phenyl group was determined by analysis of 1H,
2D COSY NMR spectra and 1D NOE experiments. On Figure 1
correlation between protons as a result of NOE experiment for
the product 1f was presented.
The assignments were confirmed for 1d by X-ray determination
of the crystal structure of its trans-isomer (Fig. 2). These type of
analysis were made only for one compound because in all cases the
structure of multiplets was characteristic for cis as well as trans
isomer.
Some 3-phenylsulfonyl-2,5-disubstituted tetrahydrofurans,
among them 2b, were obtained earlier via intramolecular addition
of alkoxide anion in homoallylic alcohols in which the double bond
was activated by phenylsulfonyl substituents.7
Attempts of the reaction of carbanions of 1, 2 and 3 with chal-
cone, an active Michael acceptor, gave a positive result only for
3-chlorobutyl phenyl sulfone 2. In this case, it was possible to
generate the carbanion before chalcone was added to the reaction
mixture. The reaction carried out in a mixture THF–toluene (3:10)
at ꢀ78 ꢁC gave the expected tetrasubstituted cyclopentane as
a mixture of three diastereoisomers along with a moderate amount
of cyclopropane 2a.
Product Yield Ratio of isomers Product Yield
[%]
2,5-trans–cisd
[%]
1
2
Ph
1b
68
70
56
53
53
60
38:62
67:33
57:43
29:71
31:69
62:38
1a
1a
1a
1a
1a
1a
10
16
6
15
17
25
p-MeO–C6H4 1c
p-Me–C6H4
p-Cl–C6H4
Ph-CH]CH
(CH3)3C
1d
1e
1f
1g
Ph
2b
2b
60
78
82
92
53
79
11
84:16
91:9
97:3
97:3
93:7
2a
2a
2a
2a
2a
2a
2a
16
15
12
5
28
<1
35
Phb
b
p-MeO–C6H4 2c
p-Me–C6H4
b
2d
2e
2f
b
p-Cl–C6H4
(CH3)3Cb
100:0
100:0
b
n-C4H9
2g
3
Phb,c
p-MeO–C6H4 4c
p-Me–C6H4
p-Cl–C6H4
4b
42c
50c
45c
28c
100:0
100:0
100:0
100:0
4a
4a
4a
4a
d
d
d
d
b
b
4d
4e
b
a
b
c
Sulfones identified by numbers 1–3 as shown in Scheme 6.
Reaction in toluene.
Yield after oxidation of the initially formed 3c–e by MCPBA.
According to GC.
d
The stereochemistry of these three tetrasubstituted cyclo-
pentanes 2h, 2i and 2k was determined on the basis of 1D NOE
experiments. In all cases, the phenylsulfonyl group in position 1 is
in a trans relation to the phenyl group in position 2. In the
diastereoisomer obtained with the highest yield, 2h, substituents in
positions 3 and 4 are in a cis relation to each other and in a trans
relation to the substituent in postion 2. In the two remaining cases,
substituents in positions 3 and 4 are in a trans relation to each other
and in a cis or trans relation to the phenyl group in position 2, as
shown in Scheme 7.
The reported earlier reactions of carbanion of 3-chloropropyl
phenyl sulfone with aromatic aldehydes gave 2-aryl-3-phenyl-
sulfonyl tetrahydrofurans as single diastereoisomers with trans
2,3-substituents.1 Products of the reaction of 1 and 2 with aromatic
aldehydes were obtained as mixtures of two diastereoisomers in
which substituents in positions 2 and 3 are always in trans relation,
whereas substituent in position 5 was cis or trans in relation to aryl
or alkyl group in position 2. On the other hand, upon oxidation of
the crude product of the reaction of 3 with aldehydes 2-aryl-
3,5-diphenylsulfonyltetrahydrofurans 4b–e were obtained as single
8.9% H
3.2%
17.5%
23.8%
2.3%
3.2%
9.6%
4.5%
H
H
H
SO2Ph
H
H
5.9%
SO2Ph
H
H9.4%
Ph
2.7%
3.5%
7.9%
3.3%
Ph
H
H
4.3%
H
O
H
O
7.1%
6.5%
H
H
Ph
Ph
Figure 1.
Figure 2.

A. Brandt et al. / Tetrahedron 66 (2010) 3378–3385
3381
128.7, 128.8, 129.4, 133.9, 138.8, 139.9; IR (KBr, nmax/cmꢀ1): 3058,
2943, 1448, 1310, 1299, 1249, 1149, 1131, 1085, 814, 760, 717, 692,
561, 537, 526; MS (EI, 70 eV) m/z (%): 294(Mþ, 43), 259(17), 152(74),
143(40), 125(18), 117(100), 91(13), 77(15); HRMS (EI): calculated for
C15H1535ClO2S: 294.0481, found: 294.0476; anal. elem. calculated
for C15H1535ClO2S: C 61.11, H 5.13, Cl 12.03, S 10.88, found: C 61.02, H
5.16, Cl 12.08, S 10.72.
R
SO2Ph
Ph
R
t-BuOK
+
ArCHO
+
Cl
SO2Ph
R
SO2Ph
1a - 3a
O
R = Ph (1), CH3 (2), SPh (3)
( ) 1b - 3b
cis and trans
Scheme 6.
3.1.2. Synthesis of 3-chlorobutyl phenyl sulfone (2). To a solution of
triphenylphosphine (9.81 g, 37.44 mmol) in CH3CN (100 mL) at
35 ꢁC CCl4 (5.9 mL, 51.4 mmol) was added, the mixture was warmed
to 60 ꢁC and 4-(phenylsulfonyl)butan-2-ol (5 g, 23.4 mmol) was
added. After two days the solvent was evaporated, water (50 mL)
was added and the mixture was extracted with diethyl ether
(2ꢂ50 mL). The product was purified by column chromatography,
yield 4.08 g, 75%.
SO2Ph
SO2Ph
Ph
Ph
Ph
H3C
H3C
+
+
O
Ph
35%, 2h
O
CH3
15%, 2i
O
t-BuOK
+
Cl
SO2Ph
Ph
Ph
White crystals; mp: 39–40 ꢁC (EtOH); 1H NMR (500 MHz,
2
SO2Ph
SO2Ph
CDCl3):
d
¼1.52 (d, J(H,H)¼6.5 Hz, 3H), 1.98–2.08 (m, 1H), 2.20–2.28
Ph
H3C
(m, 1H), 3.23 (ddd, J(H,H)¼5.2, 10.3, 14.0 Hz, 1H), 3.35 (ddd,
J(H,H)¼5.2, 10.3, 14.0 Hz, 1H), 4.05–4.15 (m, 1H), 7.55–7.63 (m, 2H),
7.65–7.72 (m, 1H), 7.90–7.94 (m, 2H); 13C NMR (125 MHz, CDCl3):
H3C
15%, 2a
Ph
3%, 2k
O
d
¼25.2, 32.9, 53.7, 56.2, 128.0, 129.4, 133.9, 139.1; IR (film in CH2Cl2,
nmax/cmꢀ1): 3628, 3546, 3066, 2977, 2929, 1981, 1906, 1820, 1777,
1688, 1615,1585,1479,1447,1407,1382,1306,1290,1231,1179,1145,
1086, 1024, 999, 941, 910, 887, 800, 745, 689, 616, 589, 562, 537; MS
(EI, 70 eV) m/z (%): 232(Mþ, 2), 156(34), 143(53), 132(18), 125(12),
117(11), 91(21), 77(92), 63(19), 55(100), 51(50), 39(20); HRMS (EI):
calculated for C10H13O2S35Cl: 232.0325, found: 232.0320; anal.
elem. calculated for: C10H13O2S35Cl: C 51.61, H 5.63, S 13.78, Cl
15.23, found: C 51.64, H 5.59, S 14.04, Cl 15.28.
Scheme 7.
2. Conclusions
Substituents in the 3-positions of carbanions of 3-chloropropyl
phenyl sulfones affect the rates of intramolecular 1,3-substitution
and leads to competition between this process and intermolecular
addition to aldehydes. The aldol type anions produced in such
addition reactions undergo intramolecular 1,5-substitution giving
trisubstituted tetrahydrofurans. It was shown that a variety of
2,3,5-trisubstituted tetrahydrofurans could be obtained according
to this procedure.
3.1.3. Synthesis of 3-chloro-1-phenylsulfonyl-3-(phenylthio)propane
(3). To a stirred solution of 1-phenylsulfonyl-3-(phenylthio)propane
(18 g, 61.6 mmol) in CCl4 (70 mL), N-chlorosuccinimide (9.02 g,
67.8 mmol) was added in small portions. The mixture was stirred for
24 h the precipitate was filtered of, washed with CCl4, and the
solvent was evaporated. Crude product, yield 19.10 g, 95% was used
without further purification.
3. Experimental section
3.1. General
Oil; 1H NMR (500 MHz, CDCl3):
d
¼2.39–2.49 (m, 1H), 2.48–2.56
(m, 1H), 3.36–3.45 (m, 2H), 5.31–5.36 (m, 1H), 7.23–7.42 (m, 5H),
Reactions of carbanions were conducted in flame-dried appara-
tus under atmosphere of argon. Column chromatography was per-
7.49–753 (m, 2H), 7.66–7.71 (m, 1H), 7.89–7.95 (m, 2H); 13C NMR
(125 MHz, CDCl3):
d
¼32.3, 53.3, 67.9, 128.0, 129.2, 129.3, 129.4,
formed on Fisher Scientific Matrex Silica 60 (35–70
m
). Melting
130.9,133.7,134.0,138.8; IR (film in CH2Cl2, nmax/cmꢀ1): 3060, 2989,
2927,1718,1584,1477,1447,1440,1402,1318,1308,1150,1086,1024,
999, 973, 814, 746, 689, 590, 560; MS (EI, 70 eV) m/z (%): 149(100),
134(14), 116(33), 77(18); HRMS (EI): calculated for C15H15O2S235Cl:
326.0202, found: 326.0188.
points were measured on a Griffin electrothermal apparatus. IR
spectra were recorded on a Perkin–Elmer Spectrum One FTIR spec-
trometer 1H and 13C NMR spectra were recorded on Bru¨cker DPX300
or DRX500 Fourier Transform spectrometers using an internal deu-
terium lock. Electron spray ionisation (ES) was performed on either
a Micromass LCT TOF spectrometer or a Waters-Micromass ZMD
spectrometer. High resolution mass spectrometry (HRMS) was
obtained by peak matching using polyethylene glycols as a standard.
3.1.4. Synthesis of trans-2-phenyl-phenylsulfonyl cyclopropane
(1a). To a solution of 3-chloro-3-phenyl-propylphenylsulfone (1)
(100 mg, 0.34 mmol) in THF (10 mL), at ꢀ30 ꢁC a solution of t-BuOK
(76 mg, 0.68 mmol) in THF (2 mL) was added dropwise. The mix-
ture was stirred at ꢀ30 ꢁC for 20 min, the cooling was removed and
aqueous solution of NH4Cl (10 mL) was added. The mixture was
extracted with CH2Cl2 (2ꢂ20 mL), organic layer was washed with
brine, dried over MgSO4 and solvent was evaporated. The product
was purified by column chromatography, yield 73 mg, 84%.
3.1.1. Synthesis of 3-chloro-3-phenyl-propyl phenyl sulfone (1). 1-
Phenyl-3-(phenylsulfonyl)propan-1-ol8 (2.0 g, 7.31 mmol) was
dissolved in CH2Cl2 (4 mL) and stirred with 35% HCl (4 mL). The
progress of the reaction was monitored by TLC. After the reaction
was completed the mixture was poured onto cold 10% solution of
HCl (10 mL), saturated aqueous solution of NaHCO3 (20 mL) was
added, and mixture was extracted with CH2Cl2 (2ꢂ10 mL). The
organic phase was washed with water (20 mL), dried over MgSO4,
the solvent was evaporated and the product was purified by
recrystalization from ethanol, yield 1.49 g, 70%.
White crystals; mp: 96–98 ꢁC (EtOH), lit. 96–97 ꢁC;8 1H NMR
(400 MHz, CDCl3):
d
¼1.49 (ddd, J(H,H)¼8.3, 2.6, 1.6 Hz, 1H), 1.89 (dt,
J(H,H)¼9.7, 5.5 Hz, 1H), 2.66 (ddd, J(H,H)¼8.3, 3.8, 2.9, 1H), 2.86–
2.91(m, 1H), 6.99–7.02 (m, 2H), 7.17–7.26 (m, 3H), 7.54–7.59 (m,
2H), 7.63–7.67 (m, 1H), 7.93–7.95 (m, 2H).9
White crystals; mp: 73–74 ꢁC (EtOH); 1H NMR (200 MHz,
CDCl3):
H)¼7.2 Hz, 1H), 7.26–7.39 (m, 5H), 7.53–7.73 (m, 3H), 7.88–7.94 (m,
2H); 13C NMR (50 MHz, CDCl3):
¼32.9, 53.6, 61.0, 126.7, 127.9,
d
¼2.48–2.51 (m, 2H), 3.10–3.37 (m, 2H), 4.97 (t, J (H,
3.1.5. Synthesis of trans-1-phenylsulfonyl-2-methyl cyclopropane
(2a). To a solution of 3-chlorobutyl phenyl sulfone (2) (232 mg,
1 mmol) in toluene (6 mL), at 0 ꢁC solid t-BuOK (224 mg, 2 mmol)
d

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A. Brandt et al. / Tetrahedron 66 (2010) 3378–3385
was added. After 1 h aqueous solution of NH4Cl (5 mL) was added
and the mixture was extracted with CH2Cl2 (2ꢂ50 mL). Organic
layer was dried over MgSO4, the solvent was evaporated and the
product was purified by column chromatography, yield 140 mg,
71%.
117(32), 105(56), 77(14); HRMS (ESI): calculated for C22H20O3SNa:
387.1025, found 387.1034.
2,5-trans Isomer; white crystals; mp: 168–169 ꢁC (Et2O); 1H
NMR (500 MHz, CDCl3):
d
¼2.43–2.57 (m, 2H), 4.04 (dt, J(H,H)¼9.0,
5.3 Hz, 1H), 5.12 (dd, J(H,H)¼10.0, 5.7 Hz, 1H), 5.78 (d, J(H,H)¼5.7,
Oil; 1H NMR (500 MHz, CDCl3):
d
¼0.81–0.88 (m, 1H), 1.11 (d,
1H), 7.23–7.26 (m, 1H), 7.29–7.26 (m, 9H), 7.50–7.53 (m, 2H), 7.61–
J(H,H)¼6.2 Hz, 3H), 1.47 (dt, J(H,H)¼5.0, 9.5 Hz, 1H), 1.72–1.84 (m,
7.65 (m, 1H), 7.89–7.95 (m, 2H); 13C NMR (125 MHz, CDCl3):
d¼37.8,
1H), 2.14–2.20 (m, 1H), 7.52–7.57(m, 2H), 7.60–7.66 (m, 1H), 7.86–
71.9, 79.3, 80.8, 125.5, 126.0, 127.8, 128.2, 128.6, 128.7, 129.4, 134.0,
138.1, 139.8, 140.8; IR (KBr, nmax/cmꢀ1): 3058, 3032, 2898, 2846,
1497,1448,1307,1147,1085,1055,1026, 758, 747, 722, 697, 608, 555;
MS (EI, 70 eV) m/z (%): 364(Mþ, <1), 222(100), 117(42), 105(39),
91(10), 77(15); HRMS (ESI): calculated for C22H20O3SNa: 378.1025,
found: 378.1039; anal. elem. calculated for C22H20O3S: C 72.50, H
5.53, S 8.80, found: C 72.35, H 5.61, S 9.05.
7.93 (m, 2H);10 13C NMR (125 MHz, CDCl3):
d¼14.6, 15.6, 17.4, 40.5,
127.9, 129.7, 133.8, 141.5; IR (film in CH2Cl2, nmax/cmꢀ1): 3622, 3548,
3064, 3039, 2964, 2934, 2874, 1976, 1905, 1821, 1776, 1688, 1622,
1584, 1480, 1447, 1393, 1371, 1305, 1203, 1147, 1089, 1070, 997, 922,
889, 843, 794, 766, 734, 703, 689, 587, 547; MS (EI, 70 eV) m/z (%):
196(Mþ,2), 142(3), 126(6), 77(17), 55(100), 51(16), 39(11); HRMS
(EI): calculated for C10H12O2S: 193.0558, found: 196.0561; anal.
elem. calculated for: C10H12O2S: C 61.20, H 6.16, S 16.34, found: C
61.06, H 6.28, 16.47.
3.2.2. 2-(4-Methoxyphenyl)-5-phenyl-3-phenylsulfonyl tetrahydro-
furan (1c). Yield 70%, diastereoisomers ratio trans–cis: 67:33. 2,5-
cis Isomer; white crystals; mp: 90–91 ꢁC (Et2O); 1H NMR
3.1.6. Synthesis of trans-1-phenylsulfonyl-2-(phenylthio) cyclopro-
pane (3a). To a solution of 3-chloro-1-phenylsulfonyl-3-(phenyl-
thio)propane (3) (326 mg, 1 mmol) in THF (6 mL) at ꢀ30 ꢁC, solid
t-BuOK (224 mg, 2 mmol) was added. After 30 min the mixture was
warmed to room temperature and after 30 min aqueous solution of
NH4Cl (5 mL) was added. The mixture was extracted with CH2Cl2
(2ꢂ50 mL), combined organic layer was dried over Na2SO4, the
solvent evaporated and the product was purified by column
chromatography, yield 278 mg, 96%.
(400 MHz, CDCl3):
d
¼2.24 (dt, J(H,H)¼13.9, 10.5 Hz, 1H), 2.87 (ddd,
J(H,H)¼8.0, 5.5, 2.4 Hz, 1H), 3.73–3.78 (m, 1H), 3.77 (s, 3H), 5.18
(dd, J(H,H)¼10.5, 5.7 Hz, 1H), 5.38 (d, J(H,H)¼5.7 Hz, 1H), 6.73–
6.84 (m, 2H), 7.07–7.17 (m, 2H), 7.26–7.33 (m, 1H), 7.33–7.39 (m,
2H), 7.39–7.47 (m, 2H), 7.47–7.58 (m, 2H), 7.58–7.69 (m, 1H), 7.84–
7.92 (m, 2H); 13C NMR (100 MHz, CDCl3):
d
¼36.7, 55.2, 71.2, 79.9,
80.8, 113.9, 126.0, 127.4, 128.0, 128.5, 128.6, 129.4, 132.1, 134.0,
138.2, 139.7, 159.4; IR (KBr, nmax/cmꢀ1): 3064, 3033, 2970, 2891,
1611, 1512, 1445, 1304, 1294, 1146, 1086, 1063, 1031, 827, 760, 752,
701, 689, 650, 600, 520; MS (EI, 70 eV) m/z (%): 394(Mþ, <1),
252(100), 147(15), 135(66), 117(61), 105(12), 91(14), 77(18); HRMS
(ESI): calculated for C23H22O4SNa: 417.1131, found: 401.1145;
anal. elem. calculated for C23H22O4S: C 70.03, H 5.62, S 8.13, found:
C 69.98, H 5.59, S 8.21.
White crystals; mp: 125–127 ꢁC (EtOH); 1H NMR (500 MHz,
CDCl3):
d
¼1.38 (dt, J(H,H)¼5.8, 8.8 Hz, 1H), 1.96 (dt, J(H,H)¼5.6,
8.8 Hz, 1H), 2.67–2.73 (ddd, J(H,H)¼3.7, 5.6, 9.1 Hz, 1H), 3.06–3.00
(ddd, J(H,H)¼3.7, 5.6, 9.1 Hz, 1H), 7.12–7.25 (m, 5H), 7.56–7.50 (m,
2H), 7.62–7.67 (m, 1H), 7.83–7.87 (m, 2H); 13C NMR (125 MHz,
CDCl3):
d
¼14.4, 21.0, 42.5, 126.5, 127.7, 128.4, 129.0, 129.4, 133.7,
2,5-trans Isomer; white crystals; mp: 134–135 ꢁC (Et2O); 1H
NMR (400 MHz, CDCl3):
J(H,H)¼9.3, 5.7 Hz, 1H), 5.12 (dd, J(H,H)¼9.9, 5.7 Hz, 1H), 5.7 (d,
J(H,H)¼5.7 Hz, 1H), 6.80–6.86 (m, 2H), 7.20–7.27 (m, 3H), 7.27–7.34
(m, 2H), 7.34–7.39 (m, 3H), 7.48–7.56 (m, 2H), 7.84–7.92 (m, 2H); 13C
134.9, 139.9; IR (KBr, nmax/cmꢀ1): 3095, 3062, 3042, 3014, 1582,
1480, 1447, 1438, 1321, 1297, 1185, 1146, 1090, 1073, 1025, 995, 903,
890, 770, 746, 736, 686, 588, 542; MS (EI, 70 eV) m/z (%): 290(Mþ,
2), 150(11), 149(100), 147(23), 134(16), 116(43), 115(25), 77(13),
51(11); HRMS (EI): calculated for C15H14O2S2: 290.0435, found:
290.0445; anal. elem. calculated for: C15H14O2S2: C 62.04, H 4.86, S
22.08, found: C 61.97, H 4.74, S 21.94.
d¼2.43–2.59 (m, 2H), 3.78 (s, 3H), 4.02 (dt,
NMR (100 MHz, CDCl3):
d¼37.7, 55.3, 71.7, 79.2, 80.6, 114.0, 126.0,
127.0, 128.2, 128.6, 128.7, 129.4, 132.6, 134.0, 138.1, 140.0, 159.2; IR
(KBr, nmax/cmꢀ1): 3063, 3033, 2935, 2837, 1612, 1513, 1447, 1305,
1250, 1176, 1148, 1086, 1031, 831, 758, 720, 700, 689, 607, 565; MS
(EI, 70 eV) m/z (%): 394(Mþ, <1), 252(100), 237(4), 221(9), 135(73),
117(51), 91(11), 77(13); HRMS (EI): calculated for C23H22O4S:
394.1239, found: 394.1254; anal. elem. calculated for C23H22O4S: C
70.03, H 5.62, S 8.13, found: C 70.05, H 5.88, S 8.16.
3.2. General procedure for the reaction of 3-chloro-3-phenyl-
propyl phenyl sulfone (1) with aldehydes
To a solution of 3-chloro-3-phenyl-propylphenylsulfone (1)
(100 mg, 0.34 mmol) and aldehydes (0.51 mmol) in THF (10 mL), at
ꢀ30 ꢁC a solution of t-BuOK (76 mg, 0.68 mmol) in THF (2 mL) was
added dropwise. The mixture was stirred at ꢀ30 ꢁC for 20 min, the
cooling was removed and aqueous solution of NH4Cl (10 mL) was
added. The mixture was extracted with CH2Cl2 (2ꢂ20 mL), organic
layer was washed with brine, dried over MgSO4 and solvent was
evaporated. The products were isolated and purified by column
chromatography.
3.2.3. 5-Phenyl-3-phenylsulfonyl-2-(4-methylphenyl) tetrahydrofu-
ran (1d). Yield 56%, diastereoisomers ratio trans–cis: 57:43. 2,5-cis
Isomer; white crystals; mp: 130–132 ꢁC (Et2O); 1H NMR (400 MHz,
CDCl3):
d
¼2.23 (dt, J(H,H)¼13.9, 10.4, 1H), 2.31 (s, 3H), 2.86 (ddd,
J(H,H)¼7.7, 5.4, 2.2 Hz, 1H), 3.76 (ddd, J(H,H)¼7.9, 5.5, 2.2 Hz, 1H),
5.21 (dd, J(H,H)¼10.6, 5.5 Hz, 1H), 5.41 (d, J(H,H)¼5.41 Hz, 1H),
7.02–7.14, (m, 4H), 7.27–7.33 (m, 1H), 7.33–7.40 (m, 2H), 7.40–7.47
(m, 2H), 7.50–7.58 (m, 2H), 7.62–7.70 (m,1H), 7.87–7.94 (m, 2H); 13C
3.2.1. 2,5-Diphenyl-3-phenylsulfonyl tetrahydrofuran (1b). Yield
68%, diastereoisomers ratio trans–cis: 38:62. 2,5-cis Isomer; white
NMR (100 MHz, CDCl3):
d
¼21.1, 36.8, 71.4, 80.0, 80.9,126.00,126.02,
128.1, 128.5, 128.7, 129.2, 129.4, 134.0, 137.2, 137.9, 138.2, 139.7; IR
(KBr, nmax/cmꢀ1): 3062, 3034, 2969, 2891, 1515, 1443, 1315, 1146,
1087, 1064, 1011, 820, 782, 748, 723, 698, 688, 649, 600; MS (EI,
70 eV) m/z (%): 236(100), 221(19), 131(21), 119(82), 105(60), 91(28),
77(16); HRMS (ESI): calculated for C23H22O3SNa: 401.1181, found:
401.1178; anal. elem. calculated for C23H22O3S: C 72.99, H 5.86, S
8.47, found: C 73.00, H 6.01, S 8.75.
crystals; mp: 106–108 ꢁC (Et2O); 1H NMR (400 MHz, CDCl3):
d
¼2.24
(dt, J(H,H)¼14.0, 10.3 Hz, 1H), 2.85 (ddd, J(H,H)¼7.7, 5.3, 2.2 Hz, 1H),
3.78 (ddd, J(H,H)¼7.8, 5.5, 2.2 Hz, 1H), 5.22 (dd, J(H,H)¼10.6, 5.3 Hz,
1H), 5.45 (d, J(H,H)¼5.5 Hz, 1H), 7.20–7.28 (m, 4H), 7.28–7.33 (m,
1H), 7.33–7.41 (m, 3H), 7.41–7.47 (m, 2H), 7.50–7.58 (m, 2H), 7.62–
7.68 (m, 1H), 7.87–7.95 (m, 2H); 13C NMR (100 MHz, CDCl3):
d¼36.7,
71.4, 80.0, 81.0, 126.0, 126.1, 128.08, 128.14, 128.52, 128.55, 128.7,
129.4, 134.0, 138.2, 139.6, 140.1; IR (KBr, nmax/cmꢀ1): 3039, 2948,
2895, 1494, 1459, 1445, 1302, 1291, 1142, 1086, 1054, 1015, 758, 750,
721, 699, 690, 598; MS (EI, 70 eV) m/z (%): 364(Mþ, <1), 223(100),
2,5-trans Isomer; white crystals; mp: 141–142 ꢁC (Et2O); 1H
NMR (400 MHz, CDCl3):
J(H,H)¼8.6, 5.3 Hz, 1H), 5.11 (dd, J(H,H)¼10.0, 5.8 Hz, 1H), 5.76 (d,
J(H,H)¼5.3 Hz, 1H), 7.09–7.15 (m, 2H), 7.21–7.24 (m, 2H), 7.27–7.37
d
¼2.32 (s, 3H), 2.39–2.57 (m, 2H), 4.03 (dt,

A. Brandt et al. / Tetrahedron 66 (2010) 3378–3385
3383
(m, 5H), 7.49–7.56 (m, 2H), 7.61–7.67 (m, 1H), 7.87–7.93 (m, 2H); 13
NMR (100 MHz, CDCl3):
¼21.0, 37.8, 71.8, 79.2, 80.7, 125.4, 126.1,
C
91(57), 77(100), 65(16), 51(54), 39(20); HRMS (ESI): calculated for
C24H22O3SNa: 413.1181, found: 413.1200; anal. elem. calculated for
C24H22O3S: C 73.82, H 5.68, S 8.21, found: C 73.89, H 5.76, S 8.23.
d
128.2, 128.6, 128.7, 129.34, 129.37, 134.0, 137.5, 137.7, 138.1, 139.9; IR
(KBr, nmax/cmꢀ1): 3060, 3025, 2924, 2899, 1514, 1445, 1294, 1144,
1086, 1063, 1048, 1020, 932, 800, 756, 718, 702, 689, 600, 564, 549,
515, 495; MS (EI, 70 eV) m/z (%): 236(76), 221(22), 131(24),
119(100), 105(15), 91(39), 77(30), 65(7), 51(9); HRMS (ESI): calcu-
lated for C23H22O3SNa: 401.1182, found: 401.1179; anal. elem. cal-
culated for C23H22O3S: C 72.99, H 5.86, S 8.47, found: C 72.88, H 5.81,
S 8.42.
3.2.6. 2-tert-butyl-5-phenyl-3-phenylsulfonyl tetrahydrofuran (1g).
Yield 60%, diastereoisomers ratio trans–cis: 62:38. 2,5-cis Isomer;
Oil; 1H NMR (400 MHz, CDCl3):
d
¼0.89 (s, 9H), 1.79–2.00 (m, 1H),
2.67 (ddd, J(H,H)¼13.9, 4.9, 0.7 Hz, 1H), 3.56 (dd, J(H,H)¼9.3, 3.8 Hz,
1H), 4.32 (d, J(H,H)¼3.6 Hz, 1H), 5.09 (dd, J(H,H)¼11.4, 4.8 Hz, 1H),
7.30–7.42 (m, 5H), 7.57–7.65 (m, 2H), 7.65–7.76 (m, 1H), 7.94–8.05
(m, 2H); 13C NMR (100 MHz, CDCl3):
d
¼25.7, 34.8, 37.6, 66.2, 80.1,
3.2.4. 2-(4-Chlorophenyl)-5-phenyl-3-phenylsulfonyl tetrahydrofu-
ran (1e). Yield 53%, diastereoisomers ratio trans–cis: 29:71. 2,5-cis
85.4, 125.8, 127.8, 128.4, 129.0, 129.4, 134.0, 138.3. 140.2; IR (film in
CH2Cl2, nmax/cmꢀ1): 3064, 2960, 2906, 1478, 1447, 1307, 1148, 1087,
1070, 1029, 759, 718, 700, 690, 601, 654; MS (EI, 70 eV) m/z (%):
344(Mþ, 1), 287(12), 202(18), 145(100), 117(95), 104(38), 91(20),
77(27), 57(42), 51(12), 41(22); HRMS (EI): calculated for C20H24O3S:
344.1446, found: 344.1435.
Isomer; Oil; 1H NMR (400 MHz, CDCl3):
d
¼2.22 (dt, J(H,H)¼13.9,
10.4 Hz, 1H), 2.83 (ddd, J(H,H)¼7.8, 5.5, 2.4 Hz, 1H), 3.72 (ddd,
J(H,H)¼8.0, 5.7, 2.3 Hz, 1H), 5.20 (dd, J(H,H)¼10.5, 5.4 Hz, 1H), 5.45
(d, J(H,H)¼5.7 Hz, 1H), 7.14–7.23 (m, 2H), 7.23–7.28 (m, 2H), 7.28–
7.35 (m, 1H), 7.35–7.47 (m, 4H), 7.51–7.63 (m, 2H), 7.63–7.75 (m,
2,5-trans Isomer; Oil; 1H NMR (400 MHz, CDCl3):
2.31–2.44 (m, 1H), 2.44–2.57 (m, 1H), 3.73–3.84 (m, 1H), 4.50 (d,
J(H,H)¼4.2 Hz, 1H), 5.02 (dd, J(H,H)¼9.1, 6.7 Hz, 1H), 7.18–7.38 (m,
5H), 7.49–7.58 (m, 2H), 7.63–7.71 (m, 1H), 7.87–7.92 (m, 2H); 13C
d¼0.95 (s, 9H),
1H), 7.86–7.97 (m, 2H); 13C NMR (100 MHz, CDCl3):
d
¼36.7, 71.3,
79.3, 81.0, 126.0, 127.5, 128.2, 128.61, 128.65, 128.71, 129.5, 134.0,
134.2, 138.1, 138.7, 139.3; IR (KBr, nmax/cmꢀ1): 3057, 3029, 2945,
1492, 1446, 1334, 1306, 1286, 1152, 1086, 1036, 1014, 835, 818, 767,
751, 720, 700, 688, 608, 520; MS (EI, 70 eV) m/z (%): 256(37),
221(11), 151(20), 139(47), 117(85), 105(100), 91(17), 77(46), 51(18);
HRMS (ESI): calculated for C22H1935ClO3SNa: 421.0636, found:
421.0640.
NMR (100 MHz, CDCl3):
127.9, 128.5, 128.9, 129.3, 133.9, 138.2, 141.2; IR (film in CH2Cl2, nmax
d
¼26.3, 36.5, 38.3, 66.0, 81.7, 86.9, 126.2,
/
cmꢀ1): 3065, 2962, 2872, 1478, 1447, 1306, 1145, 1086, 1067, 1031,
986, 746, 717, 690, 649, 591, 552, 528; MS (EI, 70 eV) m/z (%):
344(Mþ, 7), 202(26), 185(9), 161(10), 145(75), 117(83), 105(100),
91(43), 77(37), 57(47), 41(26); HRMS (EI): calculated for C20H24O3S:
344.1446, found: 344.1459.
2,5-trans Isomer; white crystals; mp: 139–141 ꢁC (Et2O); 1H
NMR (400 MHz, CDCl3):
d
¼2.49 (m, 2H), 3.97 (ddd, J(H,H)¼9.5, 3.8,
1.2 Hz, 1H), 5.10 (dd, J(H,H)¼9.9, 5.7 Hz, 1H), 5.76 (d, J(H,H)¼5.7 Hz,
1H), 7.26–7.33 (m, 4H), 7.33–7.40 (m, 5H), 7.49–7.60 (m, 2H), 7.62–
3.3. General procedure for the reactions of 2 with aldehydes
7.71 (m, 1H), 7.85–7.96 (m, 2H); 13C NMR (100 MHz, CDCl3):
d
¼38.1,
71.9, 78.7, 81.0, 126.0, 127.0, 128.4, 128.63, 128.65, 128.8, 129.5,
133.6, 134.2, 138.0, 139.4, 139.5; IR (KBr, nmax/cmꢀ1): 3064, 3032,
1492, 1447, 1305, 1144, 1085, 1014, 766, 725, 700, 689, 595, 575, 545,
525; MS (EI, 70 eV) m/z (%): 256(100), 221(21), 151(11), 139(29),
117(35), 105(9), 77(32), 51(14); HRMS (ESI): calculated for
C22H1935ClO3SNa: 421.0636, found: 421.0620.
To a solution of 3-chlorobutyl phenyl sulfone (2) (232 mg,
1 mmol) and aldehyde (1.5 mmol) in toluene (8 mL), at 0 ꢁC solid
t-BuOK (224 mg, 2 mmol) was added, warmed slowly to room
temperature during 6 h, and kept for 18 h. Aqueous solution of
NH4Cl (5 mL) was added and the mixture was extracted with
CH2Cl2 (2ꢂ25 mL). Organic layer was dried over Na2SO4, the solvent
was evaporated and the products were purified by column
chromatography.
3.2.5. 5-Phenyl-3-phenylsulfonyl-2-(2-phenylvinyl) tetrahydrofuran
(1f). Yield 53%, diastereoisomers ratio trans–cis: 31:69. 2,5-cis
Isomer; white crystals; mp: 142–143 ꢁC (Et2O); 1H NMR (400 MHz,
3.3.1. 2-Phenyl-3-phenylsulfonyl-5-methyl tetrahydrofuran, 2,5-cis
isomer (2b). Yield 78%; white crystals; mp: 128–129 ꢁC (EtOH), lit.
CDCl3):
d
¼2.22 (dt, J(H,H)¼13.6, 10.3 Hz, 1H), 2.92 (ddd, J(H,H)¼9.5,
6.0, 3.5 Hz, 1H), 3.68 (ddd, J(H,H)¼10.3, 6.8, 3.7 Hz, 1H), 4.95 (dt,
J(H,H)¼6.6, 1.1 Hz, 1H), 5.11 (dd, J(H,H)¼9.7, 6.0 Hz, 1H), 6.03 (dd,
J(H,H)¼15.9, 6.6 Hz, 1H), 6.39 (d, J(H,H)¼15.7 Hz, 1H), 7.15–7.33 (m,
6H), 7.33–4.47 (m, 5H), 7.54–7.61 (m, 2H), 7.61–7.68 (m, 1H), 7.93–
125–126 ꢁC (CH2Cl2);7b 1H NMR (500 MHz, CDCl3):
d
¼1.38 (d,
J(H,H)¼6.0 Hz, 3H), 1.82–1.94 (m, 1H), 2.58 (ddd, J(H,H)¼2.2, 5.0,
13.7 Hz, 1H), 3.65–3.70 (m, 1H), 4.26–4.36 (m, 1H), 5.26 (d,
J(H,H)¼5.5 Hz, 1H), 7.08–7.16 (m, 2H), 7.16–7.24 (m, 3H), 7.48–7.55
(m, 2H), 7.59–7.66 (m, 1H), 7.82–7.88 (m, 2H); 13C NMR (125 MHz,
8.02 (m, 1H); 13C NMR (100 MHz, CDCl3):
d¼36.2, 69.0, 79.6, 80.6,
126.0, 126.52, 126.58, 128.04, 128.09, 128.48, 128.54, 128.7, 129.5,
132.6, 134.1, 135.8, 138.2, 139.8; IR (film in CH2Cl2, nmax/cmꢀ1): 3061,
3029,1495, 1447,1306,1147,1086,1051, 967, 752, 720, 690, 650, 601,
552; MS (EI, 70 eV) m/z (%): 248(100), 157(13), 144(21), 131(35),
117(37), 105(25), 91(30), 77(32), 65(5), 51(11); HRMS (ESI): calcu-
lated for C24H22O3SNa: 413.1182, found: 413.1198; anal. elem. cal-
culated for C24H22O3S: C 73.82, H 5.68, S 8.21, found: C 73.61, H 5.61,
S 8.41.
CDCl3):
d
¼19.7, 35.8, 71.7, 75.9, 80.1, 126.0, 128.0, 128.4, 128.6, 129.3,
133.9, 138.3, 140.3; IR (KBr, nmax/cmꢀ1): 3060, 3035, 2976, 2957,
2871, 1962, 1906, 1820, 1776, 1697, 1584, 1457, 1446, 1388, 1370,
1344, 1301, 1288, 1257, 1146, 1102, 1083, 149, 1022, 9687, 910, 856,
785, 761, 751, 719, 699, 689, 624, 610, 554, 507; HRMS (ESI): cal-
culated for C17H18O3SNa: 325.0869, found: 325.0854; anal. elem.
calculated for: C17H18O3S: C 67.52, H 6.00, S 10.60, found: C 67.29, H
5.83, S 10.69.
2,5-trans Isomer; white crystals; mp: 134–135 ꢁC (Et2O); 1H
NMR (400 MHz, CDCl3):
d
¼2.46 (dt, J(H,H)¼12.8, 10.1 Hz, 1H), 2.58
3.3.2. 3-Phenylsulfonyl-2-(4-methoxyphenyl)-5-methyl tetrahydro-
(ddd, J(H,H)¼13.0, 7.7, 5.1 Hz, 1H), 3.82 (ddd, J(H,H)¼9.9, 3.5, 2.0 Hz,
1H), 5.07 (dd, J(H,H)¼10.1, 5.3 Hz, 1H), 5.26 (dt, J(H,H)¼6.8, 1.3 Hz,
1H), 6.07 (dd J(H,H)¼16.0, 5.9 Hz, 1H), 6.51 (dd, J(H,H)¼16.0, 1.5 Hz,
1H), 7.18–7.41 (m, 10H), 7.50–7.59 (m, 2H), 7.59–7.68 (m, 1H), 7.89–
furan, 2,5-cis isomer (2c). Yield 82%; white crystals; mp: 93–94 ꢁC
(EtOH); 1H NMR (500 MHz, CDCl3):
d
¼1.37 (d, J(H,H)¼5.9 Hz, 3H),
1.89 (dt, J(H,H)¼10.2, 13.7 Hz, 1H), 2.59 (ddd, J(H,H)¼2.7, 5.3,
13.7 Hz, 1H), 3.64 (ddd, J(H,H)¼2.7, 5.9, 10.3 Hz, 1H), 3.76 (s, 3H),
4.23–4.32 (m, 1H), 5.19 (d, J(H,H)¼5.8 Hz, 1H), 6.72–6.78 (m, 2H),
7.06 (m, 2H), 7.48–7.54 (m, 2H), 7.59–7.63 (m, 1H), 7.82–7.86 (m,
7.97 (m, 2H); 13C NMR (100 MHz, CDCl3):
d
¼37.1, 69.8, 78.7, 80.4,
126.0, 126.5, 127.3, 128.0, 128.2, 128.50, 128.56, 128.6, 129.4, 131.3,
134.1, 135.9, 138.2, 139.8; IR (film in CH2Cl2, nmax/cmꢀ1): 3061, 3029,
1495, 1147, 1305, 1148, 1086, 966, 755, 723, 691, 606, 561; MS (EI,
70 eV) m/z (%): 248(45), 157(14), 144(20), 131(57), 115(56), 105(49),
2H); 13C NMR (125 MHz, CDCl3):
d
¼19.8, 35.9, 55.2, 71.6, 75.7, 80.0,
113.8, 127.4, 128.6, 129.3, 132.2, 133.8, 138.4, 159.4; IR (KBr, nmax
cmꢀ1): 3087, 3075, 3017, 2977, 2955, 2878, 2862, 2843, 2043, 1896,
/

3384
A. Brandt et al. / Tetrahedron 66 (2010) 3378–3385
1654, 1614, 1587, 1516, 1465, 1448, 1389, 1372, 1342, 1307, 1300,
1250, 1184, 1163, 1145, 1112, 1101, 1084, 1051, 1027, 970, 920, 833,
788, 751, 720, 690, 638, 611, 559, 518; HRMS (ESI): calculated for
C18H20O4SNa: 355.0975, found: 355.0961; anal. elem. calculated
for: C18H20O4S: C 65.04, H 6.06, S 9.65, found: C 65.05, H 6.09, S 9.87.
225(35), 143(43), 141(23), 126(75), 98(100), 83(55), 77(51); HRMS
(ESI): calculated for C14H20O3SNa: 291.1025, found: 291.1038.
3.3.7. 1-Benzyl-2-phenyl-3-phenylsulfonyl-5-methyl cyclopentane. To
a solution of 3-chlorobutyl-phenyl sulfone (2) (232 mg, 1 mmol) in
THF (3 mL) cooled to ꢀ78 ꢁC t-BuOK (224 mg, 2 mmol) in THF (1 mL)
was added dropwise and after 15 s chalkon (309 mg, 1.5 mmol) in
toluene (10 mL) cooled to ꢀ78 ꢁC was added dropwise. The mixture
was warmed slowly to room temperature during 6 h and kept for
18 h. Aqueous solution of NH4Cl (5 mL) was added and the mixture
was extracted with CH2Cl2 (2ꢂ50 mL). Organic layer was dried over
Na2SO4, the solvent was evaporated and the product was purified by
column chromatography.
3.3.3. 3-Phenylsulfonyl-5-methyl-2-(4-methylphenyl) tetrahydrofu-
ran, 2,5-cis isomer (2d). Yield 92%; white crystals; mp: 113–114 ꢁC
(EtOH); 1H NMR (500 MHz, CDCl3):
d
¼1.38 (d, J(H,H)¼6.0 Hz, 3H),
1.87 (dt, J(H,H)¼10.2, 13.7 Hz, 1H), 2.28 (s, 3H), 2.58 (ddd,
J(H,H)¼2.4, 5.2,13.7 Hz,1H), 3.64 (ddd, J(H,H)¼2.4, 5.6, 10.2 Hz,1H),
5.22 (d, J(H,H)¼5.6 Hz, 1H), 4.25–4.37 (m, 1H), 7.55–7.48 (m, 2H),
6.94–7.10 (m, 4H), 7.82–7.88 (m, 2H), 7.59–7.66 (m, 1H); 13C NMR
(125 MHz, CDCl3):
d
¼19.7, 21.1, 35.8, 71.8, 75.8, 80.1, 125.9, 128.6,
Compound 2h Yield 15%; 1H NMR (500 MHz, CDCl3):
d
¼1.04 (d,
129.1, 129.3, 133.8, 137.3, 137.7, 138.4; IR (KBr, nmax/cmꢀ1): 3058,
3027, 2990, 2966, 2937, 2884, 1900, 1818, 1770, 1674, 1614, 1583,
1516, 1478, 1446, 1392, 1370, 1351, 1304, 1233,1213, 1180, 1152, 1146,
1098, 1085, 1073, 1040, 1020, 998, 946, 906, 849, 825, 777, 746, 722,
687, 639, 623, 564, 536, 516; HRMS (ESI): calculated for
C18H20O3SNa: 339.1025, found: 339.1014; anal. elem. calculated for:
C18H20O3S: C 68.33, H 6.37, S 10.13, found: C 68.13, H 6.61, S 10.21.
J(H,H)¼6.6 Hz, 3H), 2.00–2.12 (m, 1H), 2.58–2.69 (m, 1H), 2.82 (ddd,
J(H,H)¼3.4, 7.5, 14.4 Hz, 1H), 3.59 (t, J(H,H)¼10.1 Hz, 1H), 3.91–4.01
(m, 2H), 6.87–6.92 (m, 2H), 7.00–7.07 (m,3H), 7.28–7.33 (m, 2H),
7.35–7.41 (m, 2H), 7.43–7.53 (m, 2H), 7.59–7.66 (m, 2H), 7.76–7.83
(m, 2H); 13C NMR (125 MHz, CDCl3):
d
¼18.4, 35.4, 39.8, 52.0, 63.1,
69.3, 126.8, 127.0, 128.1, 128.4, 128.5, 128.6, 128.9, 133.0, 133.4, 137.8,
138.1, 140.5, 200.4; IR (KBr, nmax/cmꢀ1): 3317, 2969, 2958, 2870,
1669, 1594, 1579, 1497, 1479, 1447, 1377, 1358, 1302, 1285, 1253,
1146, 1086, 1005, 973, 845, 785, 769, 757, 738, 698, 599, 599; MS (EI,
70 eV) m/z (%): 263(17), 105(100), 77(16); HRMS (ESI): calculated
for C25H24O3SNa: 427.1338, found: 427.1330.
3.3.4. 2-(4-Chlorophenyl)-3-phenylsulfonyl-5-methyl tetrahydrofuran,
2,5-cis isomer (2e). Yield 53%; white crystals; mp: 141–144 ꢁC
(EtOH); 1H NMR (500 MHz, CDCl3):
d
¼1.37 (d, J(H,H)¼6.0 Hz, 3H),
1.84 (dt, J(H,H)¼10.2, 13.5 Hz, 1H), 2.55 (ddd, J(H,H)¼2.5, 5.2,
13.5 Hz, 1H), 3.59 (ddd, J(H,H)¼2.5, 5.7, 10.2 Hz, 1H), 4.25–4.35 (m,
1H), 5.26 (d, J(H,H)¼5.7 Hz, 1H), 7.18–7.25 (m, 2H), 7.08–7.12 (m,
2H), 7.50–7.58 (m, 2H), 7.62–7.68 (m,1H), 7.83–7.90 (m, 2H); 13C
Compound 2i Yield 35%; 1H NMR (500 MHz, CDCl3):
d¼0.89 (d,
J(H,H)¼7.1 Hz, 3H), 2.30 (ddd, J(H,H)¼4.4, 7.2, 14.1 Hz, 1H), 2.64–
2.74 (m, 1H), 2.77–2.88 (m, 1H), 3.96 (ddd, J(H,H)¼7.2, 10.1, 20.1 Hz,
1H), 4.01 (dd, J(H,H)¼8.2, 10.4 Hz, 1H), 4.14 (t, J(H,H)¼10.3 Hz, 1H),
6.93–7.02 (m, 5H), 7.25–7.30 (m, 3H), 7.35–7.44 (m, 2H), 7.46–7.52
(m, 1H), 7.65–7.69 (m, 2H), 7.78–7.83 (m, 2H); 13C NMR (125 MHz,
NMR (125 MHz, CDCl3):
d
¼19.7, 35.9, 71.7, 76.0, 79.4, 127.4, 128.6,
129.4, 133.8, 134.0, 138.3, 138.9; IR (KBr, nmax/cmꢀ1): 3092, 3069,
2968, 2948, 2879, 1940, 1913, 1687, 1599, 1583, 1492, 1445, 1416,
1388, 1346, 1302, 1261, 1147, 1084, 1054, 1023, 1014, 998, 967, 913,
844, 825, 754, 721, 689, 634, 611, 554, 516; HRMS (ESI): calculated
for C18H20O3SNa: 339.1025, found: 339.1014; anal. elem. calculated
for: C17H17O335ClS: C 60.62, H 5.09, Cl 10.53, S 9.52, found: C 60.48H
5.13, Cl 10.41, S 9.60.
CDCl3):
d
¼17.1, 34.5, 35.8, 47.2, 60.4, 69.2, 126.5, 127.7, 128.0, 128.2,
128.4, 128.6, 128.7, 133.16, 133.21, 137.0, 138.4, 140.5, 197.5; IR (KBr,
nmax/cmꢀ1): 3086, 2959, 2899, 2872, 1677, 1596, 1581, 1495, 1480,
1447, 1383, 1350, 1303, 1276, 1245, 1225, 1191, 1144, 1083, 1021, 997,
959, 842, 774, 754, 709, 685, 634, 592; HRMS (ESI): calculated for
C25H24O3SNa: 427.1338, found: 427.1318; anal. elem. calculated for:
C25H24O3S: C 74.23, H 5.98, S 7.93, found: C 74.27, H 6.19, S 7.95.
3.3.5. 2-tert-Butyl-3-phenylsulfonyl-5-methyl tetrahydrofuran, 2,5-cis
Compound 2k Yield 3%; 1H NMR (500 MHz, CDCl3):
d
¼1.16 (d,
isomer (2f). Yield 79%; white crystals; mp: 138–139 ꢁC (EtOH); 1H
J(H,H)¼6.4 Hz, 3H), 2.00–2.12 (m, 1H), 2.42 (dt, J(H,H)¼7.5, 13.4 Hz,
1H), 2.83–2.99 (m, 1H), 3.86 (t, J(H,H)¼10.1 Hz, 1H), 3.90–3.94 (m,
1H), 4.15 (dd, J(H,H)¼5.9, 9.9 Hz, 1H), 6.59–6.63 (m, 2H), 6.85–6.96
(m, 3H), 7.30–7.36 (m, 2H), 7.38–7.43 (m, 2H), 7.44–7.48 (m, 1H),
7.49 (m, 1H), 7.60–7.64 (m, 2H), 7.76–7.80 (m, 2H); 13C NMR
NMR (500 MHz, CDCl3):
d
¼0.80 (s, 9H), 1.22 (d, J(H,H)¼6.0 Hz, 3H),
1.50–1.64 (m, 1H), 2.38 (dd, J(H,H)¼4.6, 13.9 Hz, 1H), 3.44 (dd,
J(H,H)¼3.5, 9.5 Hz, 1H), 4.14 (d, J(H,H)¼3.5 Hz, 1H), 4.15–4.23 (m,
1H), 7.56–7.62 (m, 2H), 7.63–7.69 (m, 1H), 7.90–7.95 (m, 2H); 13C
NMR (125 MHz, CDCl3):
d
¼19.7, 25.5, 34.3, 36.5, 66.7, 74.9, 85.4,
(125 MHz, CDCl3):
d
¼18.8, 34.5, 35.7, 49.6, 59.6, 70.5, 126.8, 127.9,
128.9, 129.3, 133.9, 138.4; IR (KBr, nmax/cmꢀ1): 3076, 2970, 2954,
2894, 2872, 1909, 1821, 1585, 1481, 1446, 1383, 1361, 1313, 1302,
1295, 1281, 1217, 1149, 1096, 1084, 1043, 1015, 964, 933, 900, 836,
782, 759, 720, 693, 641, 573, 551, 518; HRMS (ESI): calculated for
C15H22O3SNa: 305.1182, found: 305.1174; anal. elem. calculated for:
C15H22O3S: C 63.80, H 7.85, S 11.35, found: C 63.75, H 8.03, S 11.46.
128.0, 128.2, 128.3, 128.4, 129.1, 132.8, 133.5, 137.6, 138.6, 139.4,
198.7; IR (KBr, nmax/cmꢀ1): 3055, 3032, 2977, 2962, 2908, 1681,
1592, 1582, 1495, 1447, 1376, 1322, 1301, 1290, 1249, 1208, 1148,
1087, 1016, 856, 764, 724, 691, 594; HRMS (ESI): calculated for
C25H24O3SNa: 427.1338, found: 427.1322.
3.3.6. 3-Phenylsulfonyl-5-methyl-2-propyl tetrahydrofuran, 2,5-cis
isomer (2g). The reaction was performed according to general
procedure but using of methodology of the separation in time:
a solution of butyric aldehyde in toluene (2 mL) was added 15 s
after addition of solid t-BuOK to a solution of 3-chlorobutyl-
phenyl sulfone (2).
3.4. General procedure for the reaction of carbanion
generated from 3 with aldehydes
To
a
solution of 3-chloro-1-phenylsulfonyl-3-(phenyl-
thio)propane (3) (326 mg, 1 mmol) and aldehyde (2 mmol) in tol-
uene (8 mL) at 0 ꢁC solid t-BuOK (224 mg, 2 mmol) was added.
After 3 h aqueous solution of NH4Cl (5 mL) was added, the mixture
was extracted with CH2Cl2 (2ꢂ50 mL) and dried over Na2SO4. To the
solution solid NaHCO3 (0.84 g, 10 mmol) and MCPBA (0.86 g,
5 mmol) were added. After 24 h the mixture was filtered through
celitÒ, to the filtrate the water was added and the mixture was
extracted with CH2Cl2 (2ꢂ50 mL), Organic layer was dried over
Na2SO4 the solvent was evaporated and the crude product was
purified using column chromatography.
Yield 11%; oil; 1H NMR (500 MHz, CDCl3):
d
¼0.80–0.85 (m, 3H),
1.24 (d, J(H,H)¼6.0 Hz, 3H), 1.29–1.50 (m, 4H), 1.69 (dt, J(H,H)¼10.2,
13.6 Hz, 1H), 2.45 (ddd, J(H,H)¼3.1, 5.5, 13.6 Hz, 1H), 3.32–3.38 (m,
1H), 3.97–4.05 (m, 1H), 4.20–4.26 (m, 1H), 7.57–7.62 (m, 2H), 7.66–
7.70 (m, 1H), 7.89–7.94 (m, 2H); 13C NMR (125 MHz, CDCl3):
18.9, 19.8, 35.8, 37.6, 68.7, 74.9, 78.4, 128.6, 129.4, 133.9, 138.5; IR
(KBr, nmax/cmꢀ1): 3065, 2962, 2934, 2873, 1585, 1447, 1379, 1306,
1148, 1087, 986, 913, 861, 752, 718, 690, 607; MS (EI, 70 eV) m/z (%):
d¼13.8,

A. Brandt et al. / Tetrahedron 66 (2010) 3378–3385
3385
3.4.1. 2-Phenyl-3-phenylsulfonyl-5-(phenylthio) tetrahydrofuran, 2,5-
cis isomer (3b). This compound was obtained according to general
procedure without oxidation with MCPBA. Yield 162 mg, 38%.
White crystals; mp: 106–108 ꢁC (EtOH); 1H NMR (500 MHz,
2937, 2919, 2841, 1612, 1586, 1516, 1480, 1447, 1377, 1304, 1249,
1198, 1140, 1074, 1021, 976, 930, 920, 843, 819, 756, 735, 721, 685,
638, 606; MS (EI, 70 eV) m/z (%): 250(29), 175(25), 174(28), 159(22),
141(27), 125(80), 109(35), 94(12), 78(21), 77(100); HRMS (ESI):
calculated for C23H22O6S2Na: 481.0750, found: 481.0747; anal.
elem. calculated for: C23H22O6S2 C 60.24, H 4.84, S 13.99, found: C
60.38, H 4.75, S 13.86.
CDCl3):
d¼2.28–2.37 (m,1H), 2.86–2.94 (ddd, J(H,H)¼4.4, 6.1,14.2 Hz,
1H), 3.75 (q, J(H,H)¼4.7 Hz, 1H), 5.46–5.50 (d, J(H,H)¼5.7 Hz, 1H),
5.67 (dd, J(H,H)¼6.1, 8.2 Hz,1H), 7.14–7.34 (m, 8H), 7.50–7.55 (m, 4H),
7.61–7.66 (m, 1H), 7.83–7.88 (m, 2H); 13C NMR (125 MHz, CDCl3):
d
¼4.2, 70.5, 81.6, 86.4, 126.3, 127.7, 128.2, 128.5, 128.6, 129.0, 129.5,
3.4.5. 3,5-Bis(phenylsulfonyl)-2-(4-methylphenyl) tetrahydrofuran,
2,5-cis isomer (4d). Yield 45%; white crystals; mp with
decomposition: 159 ꢁC (EtOH); 1H NMR (500 MHz, CDCl3):
132.0, 133.5, 134.2, 137.9, 139.7; IR (KBr, nmax/cmꢀ1): 3082, 3057,
3045, 2970, 2920,1583,1482,1453,1445,1359,1317,1255,1188,1145,
1084, 1060, 1029, 969, 913, 802, 757, 739, 715, 690, 630, 566; MS (EI,
70 eV) m/z (%): 145(100), 143(11), 141(13), 117(14), 115(11), 77(17);
HRMS (ESI): calculated for C22H20O3S2Na: 419.0746, found:
419.0762; anal. elem. calculated for: C22H20O3S2: C 66.64, H 5.08, S
16.17, found: C 66.73, H 4.86, S 16.03.
d
¼2.32 (s, 3H), 3.00–3.10 (m, 2H), 4.15 (q, J(H,H)¼8.0, 1H), 5.08
(dd, J(H,H)¼4.6, 7.7 Hz, 1H), 5.37 (d, J(H,H)¼8.0 Hz, 1H), 7.05–7.10
(m, 2H), 7.24–7.28 (m, 2H), 7.41–7.46 (m, 2H), 7.46–7.52 (m, 2H),
7.55–7.64 (m, 2H), 7.73–7.77 (m, 2H), 7.83–7.88 (m, 2H); 13C NMR
(125 MHz, CDCl3):
d
¼21.2, 28.8, 68.2, 84.2, 92.1, 127.3, 128.3, 129.1,
129.26, 129.31, 129.40, 134.10, 134.11, 134.2, 136.0, 137.8, 138.9; IR
(KBr, nmax/cmꢀ1): 3090, 3064, 2977, 2954, 2909, 2857, 1616, 1585,
1519, 1446, 1304, 1289, 1219, 1173, 1143, 1077, 1061, 998, 918, 807,
766, 739, 720, 689, 606, 579, 551; MS (EI, 70 eV) m/z (%): 160(14),
159(100), 158(28), 131(30), 129(21), 125(19), 116(10), 115(16),
91(12), 78(17), 77(41); HRMS (ESI): calculated for C23H22O5S2Na:
465.0801, found: 465.0818; anal. elem. calculated for:
C23H22O5S2: C 62.42, H 5.01, S 14.49, found: C 62.32, H 5.06, S
14.42.
3.4.2. 1,2-Bis(phenylsulfonyl)cyclopropane (4a). 1,2-Bis(phenylsulfo-
nyl)cyclopropane (4a) was obtained according to the general
procedure without aldehyde. Yield 202 mg, 63%.
White crystals; mp: 175–180 ꢁC (EtOH); 1H NMR (500 MHz,
CDCl3):
d
¼1.89 (m, 2H), 3.12 (t, J(H,H)¼7.6 Hz, 2H), 7.36–7.42 (m,
4H), 7.50–7.59 (m, 2H), 7.65–7.71 (m, 4H); 13C NMR (125 MHz,
CDCl3):
d
¼10.6, 38.8, 127.6, 129.5, 134.1, 138.9; IR (KBr, nmax/cmꢀ1):
3107, 3029, 1790, 1765, 1582, 1573, 1450, 1413, 1324, 1220, 1150,
1084, 1035, 1011, 997, 901, 812, 784, 753, 726, 699, 586; MS (EI,
70 eV) m/z (%): 322(Mþ, 22), 181(18), 156(11), 141(47), 139(12),
125(100), 117(14), 97(16), 77(82), 51(25); HRMS (EI): calculated
forC15H14O4S2: 322.0334, found: 322.0327; anal. elem. calculated
for: C15H14O4S2: C 55.88, H 4.38, S 19.89, found: C 55.85, H 4.41, S
20.08.
3.4.6. 2-(4-Chlorophenyl)-3,5-bis(phenylsulfonyl) tetrahydrofuran,
2,5-cis isomer (4e). Yield 28%; white crystals; mp: 152–153 ꢁC
(EtOH); 1H NMR (500 MHz, CDCl3):
J(H,H)¼8.3 Hz, 1H), 5.08 (dd, J(H,H)¼4.6, 7.6 Hz, 1H), 5.38 (d,
J(H,H)¼8.0 Hz, 1H) 7.22–7.26 (m, 2H), 7.32–7.36 (m, 2H), 7.44–7.52
(m, 4H), 7.58–7.66 (m, 2H), 7.74–7.78 (m, 2H) 7.82–7.86 (m, 2H); 13C
d
¼2.98–3.08 (m, 2H), 4.11 (q,
3.4.3. 2-Phenyl-3,5-bis(phenylsulfonyl) tetrahydrofuran, 2,5-cis iso-
mer (4b). Yield 42%; white crystals; mp with decomposition:
NMR (125 MHz, CDCl3):
d
¼28.9, 68.3, 83.6, 92.3, 128.4, 128.84,
128.86, 129.2, 129.35, 129.40, 129.49, 134.3, 135.0, 135.8, 136.2,
137.9; IR (KBr, nmax/cmꢀ1): 3092, 3066, 2960, 2927, 2851, 1600,
1493, 1446, 1418, 1302, 1214, 1149, 1089, 1063, 1016, 990, 980, 931,
833, 767, 744, 728, 686, 604, 578, 564, 542; MS (EI, 70 eV) m/z (%):
286(16), 250(39), 218(22), 181(17), 180(30), 179(50), 178(79),
151(21), 149(42), 144(13), 143(15), 142(10), 141(38), 139(13),
126(11), 125(75), 116(13), 115(53), 114(10), 110(25), 109(48), 97(13),
78(43), 77(100); HRMS (ESI): calculated for C22H19O5S235ClNa:
485.0255, found: 485.0276; anal. elem. calculated for:
C22H19O5S235Cl: C 57.07, H 4.14, Cl 7.66, S 13.85, found: C 56.97, H
4.11, Cl 7.78, S 13.86.
159 ꢁC (EtOH); 1H NMR (500 MHz, CDCl3):
d
¼3.00–3.14 (m, 2H),
4.17 (q, J(H,H)¼8.0, 1H), 5.10 (dd, J(H,H)¼4.5, 7.8 Hz, 1H), 5.39 (d,
J(H,H)¼8.0 Hz, 1H), 7.24–7.30 (m, 3H), 7.35–7.40 (m, 2H), 7.42–
7.46 (m, 2H), 7.47–7.52 (m, 2H), 7.54–7.59 (m, 1H), 7.60–7.65 (m,
1H), 7.74–7.78 (m, 2H), 7.84–7.88 (m,2H); 13C NMR (125 MHz,
CDCl3):
d
¼28.7, 68.2, 84.2, 92.2, 127.3, 128.3, 128.6, 129.0, 129.2,
129.35, 129.39, 134.23, 134.29, 136.0, 137.1, 137.7; IR (KBr, nmax
/
cmꢀ1): 3068, 3036, 2961, 2900, 1584, 1479, 1446, 1309, 1258, 1147,
1083, 998, 915, 743, 718, 700, 685, 621, 604, 579, 556, 531; MS (EI,
70 eV) m/z (%): 252(10), 250(15), 145(80), 144(21), 141(22),
125(36), 117(29), 116(12), 115(49), 109(30), 105(11), 91(14),
78(22), 77(100) 65(25); HRMS (ESI): calculated for
C22H20O5S2Na: 451.0644, found: 451.0628; anal. elem. calculated
for: C22H20O5S2: C 61.66, H 4.70, S 14.97, found: C 61.49, H 4.58, S
14.96.
References and notes
1. (a) Ma˛kosza, M.; Judka, M. Chem.dEur. J. 2002, 4234; (b) Barbasiewicz, M.;
Ma˛kosza, M. Synthesis 2006, 1190; (c) Barbasiewicz, M.; Judka, M.; Ma˛kosza, M.
Russ. Chem. Bull. 2004, 53, 1771.
2. Ma˛kosza, M.; Judka, M. Helv. Chim. Acta 2005, 88, 1676.
3. Ma˛kosza, M.; Judka, M. Synlett 2004, 717.
3.4.4. 3,5-Bis(phenylsulfonyl)-2-(4-methoxyphenyl) tetrahydrofuran,
2,5-cis isomer (4c). Yield 50%; white crystals; mp with
4. Truce, E.; Goralski, C. T. J. Org. Chem 1969, 34, 3324.
5. Okuma, K.; Nishimura, K.; Ohta, H. Chem. Lett. 1984, 93.
6. Hansen, H.; Hammer, R. Acta Chem. Scand. 1973, 7, 1331.
7. (a) Craig, D.; Smith, A. M. Tetrahedron Lett. 1992, 33, 695; (b) Craig, D.; Ikin, N. J.;
Mathews, N.; Smith, A. M. Tetrahedron 1999, 55, 13471.
8. (a) Okuma, K.; Sato, Y.; Ishii, T.; Ohta, H. J. Org. Chem. 1994, 59, 2390; (b) Car-
retero, J. C.; Rojo, J.; Diaz, N.; Hamdouchi, C.; Poveda, A. Tetrahedron 1995,
51, 8507.
decomposition: 144 ꢁC (EtOH); 1H NMR (500 MHz, CDCl3):
d¼3.00–
3.13 (m, 2H), 3.79 (s, 3H), 4.12–4.22 (m, 1H), 5.05 (dd, J(H,H)¼4.1,
7.9 Hz, 1H), 5.35 (d, J(H,H)¼8.4 Hz, 1H), 6.78–6.82 (m, 2H), 7.30–
7.34 (m, 2H), 7.41–7.54 (m, 4H), 7.55–7.67 (m, 2H), 7.72–7.78 (m,
2H), 7.81–7.87 (m, 2H); 13C NMR (125 MHz, CDCl3):
d
¼28.8, 55.3,
67.9, 84.2, 92.0, 114.0, 128.3, 128.9, 129.0, 129.2, 129.3, 129.4, 134.2,
9. Tanikaga, R.; Yamada, S.; Nishikawa, T.; Matsui, A. Tetrahedron 1998, 54, 8933.
10. Cohen, T.; Tong, S. Tetrahedron 1997, 53, 9487.
134.3, 136.0, 137.8, 160.1; IR (KBr, nmax/cmꢀ1): 3058, 2998, 2969,