Study of the stereoselectivity of the nucleophilic epoxidation of 3-hydroxy-2-methylene esters

Article abstract of DOI:10.1016/j.tet.2013.11.014

The diastereoselectivity of the nucleophilic epoxidation of 3-hydroxy-2-methylene esters has been studied. The 3-hydroxy-2-methylene esters were obtained through a Morita-Baylis-Hillman reaction. The resulting epoxyesters were treated with thiophenol for transformation into 2,3-dihydroxy-2-((phenylthio)methyl), which upon treatment with triphosgene afforded the corresponding cyclic carbonates.

Full text of DOI:10.1016/j.tet.2013.11.014

Tetrahedron 70 (2014) 97e102
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Study of the stereoselectivity of the nucleophilic epoxidation of
3-hydroxy-2-methylene esters
*
ꢀ
ꢀ
ꢀ
Antonio Latorre, Jose A. Saez, Santiago Rodríguez, Florenci V. Gonzalez
ꢁ
ꢁ
ꢀ
Departament de Química Inorganica i Organica, Universitat Jaume I, 12080 Castello, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 29 August 2013
Received in revised form 28 October 2013
Accepted 7 November 2013
Available online 15 November 2013
The diastereoselectivity of the nucleophilic epoxidation of 3-hydroxy-2-methylene esters has been
studied. The 3-hydroxy-2-methylene esters were obtained through a MoritaeBayliseHillman reaction.
The resulting epoxyesters were treated with thiophenol for transformation into 2,3-dihydroxy-2-
((phenylthio)methyl), which upon treatment with triphosgene afforded the corresponding cyclic
carbonates.
Ó 2013 Elsevier Ltd. All rights reserved.
O
1. Introduction
O
O
t-BuOOLi
R
R
OMe
OMe
OMe
Stereoselective synthesis of a,b-epoxyesters is of considerable
OH
OH
synthetic interest because a number of compounds can be obtained
γ-hydroxy-α,β-unsaturated esters
by the opening of the oxirane ring.1e9 A convenient method for the
preparation of
chiral
-unsaturated esters.2 We previously reported that the
nucleophilic epoxidation of -hydroxy-
-unsaturated esters8
(Scheme 1) is a diastereoselective reaction that favor the syn iso-
mer. We have also reported that the stereoselectivity depends
highly on the substitution of the double bond and that high syn
a,b-epoxyesters is via nucleophilic epoxidation of
O
O
O
a
,b
t-BuOOLi
HMPA
R
R
g
a
,
b
OMe
OH Me
OH Me
α-methyl-γ-hydroxy-α,β-unsaturated esters
stereoselectivity (dr >19:1) is observed for the
a-methyl-
TBSO
R
O
TBSO
R
O
substituted enoates9 (Scheme 1). Free hydroxyl group resulted to be
key for the control of the stereoselectivity. The nucleophilic epox-
idation of methyl 2-methylene-3-tert-butyldimethylsilylox-
ycarboxylate esters has been recently reported by A. Myers to get
the anti diastereomer with high selectivity12 (Scheme 1). The ep-
oxidation of MoritaeBayliseHillman adducts is an interesting
transformation because the resulting epoxides can be used in the
total synthesis of interesting natural products.10e12 We now report
t-BuOOH, t-BuOK
OMe
OMe
O
THF, 0 ºC
α-methylene-β-silyloxy carboxylate esters
Scheme 1. Stereoselective nucleophilic epoxidations of unsaturated esters.
OH
O
a study of the stereoselectivity of the nucleophilic epoxidation of
hydroxy- -methylene esters.
b-
O
O
DABCO
a
+
R
OMe
R
H
OMe
1j, R = p-MeOPh
1a, R = Me
1b, R = Et
1c, R = n-Pr
1d, R = i-Bu
1e, R = Chx
2. Results and discussion
1k, R = p-FPh
1l, R = p-ClPh
We wanted to study the selectivity of epoxidation of 3-hydroxy-
methylene carboxylate esters with a range of R alkyl and aryl
groups (Scheme 2). For the preparation of the substrates, a com-
parison of different experimental procedures was performed as
1m, R = m-ClPh
1n, R = o-ClPh
1o, R = p-BrPh
1p, R = o-NO2Ph
1q, R = m-NO2Ph
1r, R = p-NO2Ph
1s, R = Furfuryl
1f, R = CH2CH2Ph
1g, R = CH=CHPh
1h, R = Ph
1i, R = p-Tol
* Corresponding author. Tel.: þ34 964729156; fax: þ34 964728214; e-mail ad-
Scheme 2. Preparation of substrates.
ꢀ
dress: fgonzale@uji.es (F.V. Gonzalez).
0040-4020/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2013.11.014

98
A. Latorre et al. / Tetrahedron 70 (2014) 97e102
OH
O
OH
O
O
OH
O
shown in Table 1. Most of the substrates were prepared in good
yield using DABCO as a base and a (1:1) mixture of dioxane/water as
reported.13 We obtained higher yields when the reaction was per-
formed at higher concentrations (10 M) than reported (see
Experimental section). Compounds 1i and j were obtained in best
yields under solvent-free conditions and longer period of time, and
compounds 1m and n were prepared using dimethylsulfoxide as
a solvent.
TBPLi
+
R
OMe
R
OMe
R
OMe
THF, -20ºC
O
3
2
1
We also epoxidized compound 1h by using oxidants other than
lithium tert-butylperoxide (Table 3). If the reaction was carried out
using tert-butyl hydrogenperoxide in the presence of sub-
stoichiometric amount of base (entry 1), then a slightly lower se-
lectivity was observed compared to the reaction carried out using
a stoichiometric amount of oxidant (entry 8, Table 2). Lithium
cumylperoxide gave similar result to lithium tert-butylperoxide
(entry 2). On the other hand, in the alkaline peroxides series, po-
tassium gave poorer stereoselectivity than either lithium or sodium
(entries 1 and 6e8). The yield of the epoxidation using m-CPBA
(entry 3) was low at rt but it increased at higher temperature (entry
4), affording the syn isomer as the major one. When m-CPBA was
used in the presence of potassium carbonate14 (entry 5), only
starting material was recovered.
Table 1
Preparation of esters 1
Entry
Substrate
Conditions
Yield
1
2
3
4
5
6
7
8
1a
1b
1c
1d
1e
1f
1g
1h
1i
1j
1k
1l
1m
1n
1o
1p
1q
1r
1s
DABCO, dioxane/H2O (1:1), 10 M, 48 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 48 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 48 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 48 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 48 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 48 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 48 h, rt
DABCO, dioxane/H2O (1:1), 12 M, 48 h, rt
DABCO, solvent-free 4 days, rt
DABCO, solvent-free 5 weeks, rt
DABCO, dioxane/H2O (1:1), 10 M, 36 h, rt
DABCO, solvent-free 5 days, rt
DABCO, DMSO 7 M, 4 days, rt
DABCO, DMSO 7 M, 4 days, rt
99
70
99
85
81
99
99
99
82
77
99
94
99
99
89
95
87
83
85
9
10
11
12
13
14
15
16
17
18
19
Table 3
Epoxidation of compound 1h
Entry
Conditionsa
2h/3h
Yield (%)b
DABCO, dioxane/H2O (1:1), 10 M, 36 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 16 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 16 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 3 h, rt
DABCO, dioxane/H2O (1:1), 10 M, 20 h, rt
1
2
3
4
5
6
7
8
TBPLi
88/12
91/9
90/10
88/12
d
66
72
28
80
NR
41
62
61
CMPLi
m-CPBA
m-CPBA
m-CPBA
TBPNa
TBPNa
TBPK
85/15
87/13
83/17
OH
O
O
O
a
For entry 1: 1.5 equiv of TBHP, 0.8 equiv of MeLi, THF, ꢀ20 ꢁC, 20 h. For entry 2:
1.5 equiv of CMHP, 1.1 equiv of MeLi, THF, ꢀ20 ꢁC, 20 h. For entry 3: 2.1 equiv of m-
CPBA, DCM, rt, 96 h. For entry 4: 2.1 equiv of m-CPBA, 70 ꢁC (sealed tube), 96 h. For
entry 5: 2.5 equiv of m-CPBA, 1.3 equiv of K2CO3, DCM, rt, 96 h. For entry 6: 2.0 equiv
of TBHP, 1.0 equiv of t-BuONa, THF, 0 ꢁC, 3 h. For entry 7: 2.0 equiv of TBHP,
0.25 equiv of t-BuONa, THF, 0 ꢁC, 3 h. For entry 8: 2.0 equiv of TBHP, 0.25 equiv of t-
BuOK, THF, 0 ꢁC, 3 h.
+
R
OMe
R
H
OMe
1
b
Esters 1 were epoxidized using lithium tert-butylperoxide
(2 equiv) as the oxidizing reagent in THF as solvent at ꢀ20 ꢁC.2,8,9
Table 2 shows that the 2 syn isomer was the major product in all
cases. For the aliphatic series (compounds 1aef), the higher steric
volume of the R pendant alkyl group the higher stereoselectivity is
observed (entries 1e6). When the R is an alkenyl group then the
epoxidation reaction is not stereoselective (entry 7). Compounds
1hes having an aromatic group gave the corresponding syn isomer
2 in very good selectivity.
Isolated yield of products corresponds to mixtures of syn and anti
diastereomers.
OH
O
OH
O
O
OH
O
oxidant
+
Ph
OMe
Ph
OMe Ph
OMe
O
3h
2h
1h
The stereochemistry of epoxides 2b and h was confirmed by
Table 2
Epoxidation of compounds 1
comparison with already reported data.12,15 The epoxyesters 2d,
3d, 2e, and 3e were transformed into cyclic carbonates through
a one-pot sequence: treatment with thiophenol in the presence of
a base, which resulted in the opening of the oxirane ring and then
addition of triphosgene to give carbonates 4, 5, 6, and 7, re-
spectively (Scheme 3). The stereochemical assignment of the car-
bonates was performed by NOE experiments (Scheme 3).
Carbonates 4 and 6 gave NOE between H-5 and methyl ester
whilst 5 and 7 gave NOE between H-5 and methylene from the
(phenylthio)methyl group.
Entry
Substrate
2/3
Yielda
1
2
3
4
5
6
7
8
Me
Et
n-Pr
i-Bu
67/33
76/24
81/19
81/19
92/8
77/23
53/47
93/7
89/11
92/8
90/10
84/16
92/8
72
70
79
71
85
59
47
68
82
73
65
52
38
52
68
43
60
65
69
Chx
PhCH2CH2
PhCH]CH
Ph
p-Tol
p-MeOPh
p-FPh
p-ClPh
m-ClPh
o-ClPh
p-BrPh
o-NO2Ph
m-NO2Ph
p-NO2Ph
Furfuryl
9
10
11
12
13
14
15
16
17
18
19
3. Conclusions
92/8
In summary, the diastereoselectivity of the nucleophilic epoxi-
dation of 3-hydroxy-2-methylene esters has been studied. The syn
isomer was the major one in all cases. The resulting 3-hydroxy 2-
epoxyesters were treated with thiophenol for transformation into
2,3-dihydroxy-2-((phenylthio)methyl), which upon treatment with
triphosgene afforded the corresponding cyclic carbonates.
90/10
83/17
80/20
91/9
93/7
a
Isolated yield of products corresponds to mixtures of syn and anti diastereomers.

A. Latorre et al. / Tetrahedron 70 (2014) 97e102
99
1.31e1.38 (1H, m), 0.90 (3H, t, J¼6.7 Hz). 13C NMR (125 MHz, CDCl3)
O
OH
O
O
d
167.0, 142.5, 124.7, 71.3, 52.0, 38.5, 19.0, 14.0 ppm.
1. NaSPh, THF, 1.5 h, 0ºC
O
O
R
R
OMe
OMe
4.2.4. Methyl 3-hydroxy-5-methyl-2-methylenehexanoate 1d.18 1H
NMR (500 MHz, CDCl3) 6.18 (1H, s), 5.78 (1H, s), 4.45 (1H, dd,
CO2Me
2. Triphosgene, py, reflux, 15 h
R
2d,2e
d
4,6
PhS
O
J¼8.5, 4.3 Hz), 3.76 (3H, s), 2.40 (1H, br s), 1.80e1.75 (1H, m),
1.58e1.51 (1H, m), 1.44e1.38 (1H, m), 0.92 (6H, m). 13C NMR
OH
O
1. NaSPh, THF, 1.5 h, 0ºC
O
(125 MHz, CDCl3)
23.3, 21.8 ppm.
d 167.0, 142.8, 124.6, 71.3, 69.9, 51.9, 45.5, 24.8,
O
O
CO2Me
2. Triphosgene, py, reflux, 15 h
R
3d,3e
4.2.5. Methyl 2-(cyclohexyl(hydroxy)methyl)acrylate 1e.19 1H NMR
(500 MHz, CDCl3)
6.23 (1H, s), 5.71 (1H, s), 4.06 (1H, d, J¼7.2 Hz),
3.76 (3H, s), 2.44 (1H, br s), 1.94 (1H, m), 1.50e1.76 (5H, m),
1.24e0.92 (5H, m). 13C NMR (125 MHz, CDCl3)
167.0, 141.2, 126.0,
53.4, 52.0, 42.4, 29.8, 28.1, 26.3, 26.1, 25.9 ppm.
5,7
PhS
d
NOE
O
NOE
O
Me
O
d
Me
O
O
O
O
O
5
4
O
5
4
H
O
H
Chx
O
SPh
4.2.6. Methyl 3-hydroxy-2-methylene-5-phenylpentanoate 1f.20 1H
NMR (500 MHz, CDCl3) 7.30e7.17 (5H, m), 6.24 (1H, s), 5.81 (1H, s),
O
O
H
O
SPh
NOE
5
4
O
O
H
NOE
Chx
d
5
4
CO2Me
SPh
6 (75%)
CO2Me
SPh
4.42 (1H, dd, J¼7.5, 5.7 Hz), 3.77(3H, s), 2.85e2.79 (1H, m), 2.73e2.69
4 (76%)
(1H, m), 2.42 (1H, br s), 2.00e1.95 (1H, m).13C NMR (125 MHz, CDCl3)
NOE
NOE
d
167.0, 141.8, 128.5, 125.9, 125.0, 70.1, 51.8, 38.0, 32.0 ppm.
7 (70%)
5 (80%)
Scheme 3. Cyclic carbonates 4e7.
4.2.7. (E)-Methyl 3-hydroxy-2-methylene-5-phenylpent-4-enoate
1g.19 1H NMR (500 MHz, CDCl3)
7.39e7.22 (5H, m), 6.67 (1H, d,
J¼16.0 Hz), 6.29 (2H, m), 5.91 (1H, s), 5.13 (1H, m), 3.78 (3H, s), 2.97
(1H, br s). 13C NMR (125 MHz, CDCl3)
166.7, 141.3, 136.5, 131.5,
d
4. Experimental section
d
129.2, 128.5, 127.8, 126.6, 125.8, 72.1, 52.0 ppm.
4.1. General experimental methods
4.2.8. Methyl 2-(hydroxy(phenyl)methyl)acrylate 1h.18 1H NMR
All solvents used in reactions were freshly distilled from appro-
priate drying agents before use.1H NMR spectra and 13C NMR spectra
were measured in CDCl3 (1H, 7.24 ppm; 13C 77.0 ppm) solution at
30 ꢁC on a 300 MHz or a 500 MHz NMR spectrometer. IR spectra were
recorded as oil films or KBr discs or NaCl pellets on a FT-IR spec-
trometer. EM Science Silica Gel 60 was used for column chroma-
tography while TLC was performed with precoated plates (Kieselgel
60, F254, 0.25 mm). Unless otherwise specified, all reactions were
carried out under argon atmosphere with magnetic stirring.
(500 MHz, CDCl3) d 7.38e7.26 (5H, m), 6.33 (1H, s), 5.83 (1H, s), 5.56
(1H, s), 3.72 (3H, s). 13C NMR (125 MHz, CDCl3)
128.3, 127.7, 126.8, 125.6, 72.7, 51.8 ppm.
d 166.7, 142.3, 141.6,
4.2.9. Methyl 2-(hydroxy(p-tolyl)methyl)acrylate 1i.18 1H NMR
(300 MHz, CDCl3)
7.26 (2H, d, J¼8.0 Hz), 7.15 (2H, d, J¼8.0 Hz), 6.32
(1H, s), 5.85 (1H, s), 5.53 (1H, s), 3.71 (3H, s), 2.34 (3H, s). 13C NMR
d
(125 MHz, CDCl3)
51.9, 21.1 ppm.
d 166.8, 142.1, 138.4, 137.5, 129.1, 126.5, 125.8, 73.1,
4.2. General experimental procedure for the preparation of
compounds 1aes
4.2.10. Methyl 2-(hydroxy(4-methoxyphenyl)methyl)acrylate 1j.20
1H NMR (300 MHz, CDCl3)
7.28 (2H, d, J¼8.8 Hz), 6.86 (2H, d,
d
J¼8.7 Hz), 6.31 (1H, s), 5.84 (1H, s), 5.52 (1H, s), 3.79 (3H, s), 3.71
To a solution of aldehyde (1 mmol) in dioxane/water (1:1)
(0.1 mL) was added methyl acrylate (3 mmol) and DABCO (1 mmol).
The reaction was monitored by TLC. Upon completion, water
(70 mL) was added and poured onto a separatory funnel and
extracted with ethyl ether or dichloromethane (3ꢂ30 mL), dried
over anhydrous Na2SO4, filtered, and concentrated under reduced
pressure. The crude was purified through chromatography (silica-
gel, hexanes/ethyl acetate (8:2), (6:4)) to afford the desired
compound.
(3H, s). 13C NMR (75 MHz, CDCl3)
125.5, 113.8, 72.7, 55.2, 51.9 ppm.
d 166.8, 159.2, 142.2, 133.5, 127.9,
4.2.11. Methyl 2-((4-fluorophenyl)(hydroxy)methyl)acrylate 1k.20 1H
NMR (500 MHz, CDCl3)
7.33 (2H, dd, J¼8.5, 5.5 Hz), 7.01 (2H, t,
J¼8.7 Hz), 6.32 (1H, s), 5.82 (1H, s), 5.53 (1H, s), 3.73 (3H, s), 3.02
(1H, br s). 13C NMR (125 MHz, CDCl3)
d
d
166.6, 162.3 (d, J¼245 Hz),
141.9, 137.0, 128.3 (dd, J¼7.2, 21.3 Hz), 126.0 (dd, J¼15.0, 21.3 Hz),
115.2 (dd, J¼12.5, 22.5 Hz), 72.6, 52.2 ppm.
4.2.1. Methyl 3-hydroxy-2-methylenebutanoate 1a.16 1H NMR
4.2.12. Methyl 2-((4-chlorophenyl)(hydroxy)methyl)acrylate 1l.18 1H
(500 MHz, CDCl3)
d
6.19 (1H, s), 5.81 (1H, s), 4.59 (1H, q, J¼6.5 Hz),
NMR (500 MHz, CDCl3) d 7.54 (1H, m), 7.34 (1H, m), 7.21e7.30 (2H,
3.76 (3H, s), 2.61 (1H, br s), 1.36 (3H, d, J¼6.5 Hz). 13C NMR
m), 6.32 (1H, s), 5.97 (1H, s), 5.58 (1H, m), 3.76 (3H, s), 3.26 (1H, br
(125 MHz, CDCl3)
d
167.1, 143.6, 124.0, 67.2, 51.8, 22.1 ppm.
s). 13C NMR (125 MHz, CDCl3)
127.9, 126.3, 72.7, 52.0 ppm.
d 166.6, 141.6, 139.8, 133.6, 128.6,
4.2.2. Methyl 3-hydroxy-2-methylenepentanoate 1b.17 1H NMR
(500 MHz, CDCl3)
6.22 (1H, s), 5.78 (s, 1H), 4.31 (1H, t, J¼7.0 Hz),
d
4.2.13. Methyl 2-((3-chlorophenyl)(hydroxy)methyl)acrylate 1m.20
1H NMR (500 MHz, CDCl3)
7.37 (1H, s), 7.26 (3H, m), 6.34 (1H, s),
5.83 (s, 1H), 5.51 (1H, s), 3.72 (s, 3H), 3.03 (1H, br s). 13C NMR
(125 MHz, CDCl3) 166.5, 143.4, 141.4, 134.4, 129.7, 127.9, 126.7,
3.76 (3H, s), 2.43 (1H, br s), 1.73e1.61 (2H, m), 0.93 (3H, t, J¼7.4 Hz).
d
13C NMR (125 MHz, CDCl3)
10.0 ppm.
d 167.0, 142.3, 124.7, 72.0, 51.5, 29.0,
d
126.6, 124.7, 72.7, 52.0 ppm.
4.2.3. Methyl 3-hydroxy-2-methylenehexanoate 1c.18 1H NMR
(500 MHz, CDCl3)
6.20 (1H, s), 5.78 (1H, s), 4.38 (1H, t, J¼6.5 Hz),
3.76 (3H, s), 2.41 (1H, br s), 1.63e1.58 (2H, m), 1.49e1.45 (1H, m),
d
4.2.14. Methyl 2-((2-chlorophenyl)(hydroxy)methyl)acrylate 1n.20
1H NMR (500 MHz, CDCl3)
d 7.54 (1H, m), 7.34 (1H, m), 7.21e7.30

100
A. Latorre et al. / Tetrahedron 70 (2014) 97e102
(2H, m), 6.32 (1H, s), 5.97 (1H, s), 5.58 (1H, m), 3.76 (3H, s), 3.25 (1H,
br s). 13C NMR (125 MHz, CDCl3)
166.9, 140.9, 134.5, 132.8, 128.9,
128.1, 127.0, 126.8, 68.9, 52.0 ppm.
2.98 (1H, d, J¼6.0 Hz), 2.55 (1H, br s), 1.72 (1H, m), 1.48 (1H, m), 0.98
d
(3H, t, J¼6.7 Hz). 13C NMR (125 MHz, CDCl3)
d 170.0, 71.0, 50.1, 52.5,
49.6, 26.0, 9.9 ppm. IR (KBr)
d 3770, 3457, 2939, 2360, 1869, 1637,
1541,1440,1348,1197,1139,1055, 950, 758 cmꢀ1. HRMS m/z calcd for
C7H12O4Na [MþNaþ]: 183.0633, found: 183.0636 (Yield 2c/3c¼99%).
4.2.15. Methyl 2-((4-bromophenyl)(hydroxy)methyl)acrylate 1o.20
1H NMR (300 MHz, CDCl3)
7.47 (2H, m), 7.25 (2H, m), 6.33 (1H, s),
5.82 (1H, s), 5.51 (1H, m), 3.73 (3H, s), 3.04 (1H, br s). 13C NMR
d
4.3.3. syn-Methyl 2-(1-hydroxybutyl)oxirane-2-carboxylate 2c. 1H
(75 MHz, CDCl3)
51.9 ppm.
d
166.4, 141.9, 140.6, 131.4, 128.6, 125.9, 121.6, 71.9,
NMR (500 MHz, CDCl3) d 3.84e3.87 (1H, m), 3.78 (3H, s), 3.12 (1H,
d, J¼5.9 Hz), 2.98 (1H, d, J¼5.9 Hz), 1.69e1.40 (4H, m), 0.94 (3H, t,
J¼7.2 Hz). 13C NMR (125 MHz, CDCl3)
d 170.0, 69.3, 58.3, 52.4, 49.6,
35.0, 18.7, 13.8 ppm. IR (KBr) d 3649, 2960, 2361, 1740, 1560, 1457,
4.2.16. Methyl 2-((2-nitrophenyl)(hydroxy)methyl)acrylate 1p.18 1H
NMR (500 MHz, CDCl3)
7.95 (1H, dd, J¼8.2, 1.3 Hz), 7.75 (1H, dd,
J¼7.9, 1.3 Hz), 7.64 (1H, td, J¼7.7, 1.3 Hz), 7.46 (1H, td, J¼8.5, 1.4 Hz),
6.37 (1H, s), 6.20 (1H, s), 5.73 (1H, s), 3.73 (3H, s), 3.35 (1H, br s). 13
NMR (75 MHz, CDCl3) 163.8, 145.6, 138.5, 133.7, 130.8, 126.3, 126.0,
123.7, 121.9, 64.7, 49.5 ppm.
d
1382, 1197, 1139, 1077, 983, 760 cmꢀ1. HRMS m/z calcd for
C8H14O4Na [MþNaþ]: 197.0790, found: 197.0786.
C
d
4.3.4. anti-Methyl 2-(1-hydroxybutyl)oxirane-2-carboxylate 3c. 1H
NMR (500 MHz, CDCl3) d 4.12e4.10 (1H, m), 3.78 (3H, s), 3.08 (1H, d,
J¼6.0 Hz), 2.98 (1H, d, J¼6.0 Hz), 1.77 (1H, br s), 1.61e1.37 (4H, m),
4.2.17. Methyl 2-((3-nitrophenyl)(hydroxy)methyl)acrylate 1q.18 1H
NMR (500 MHz, CDCl3)
0.94 (3H, t, J¼7.1 Hz). 13C NMR (125 MHz, CDCl3)
d 170.0, 69.0, 59.4,
d
8.26 (1H, m), 8.14 (1H, ddd, J¼8.2, 2.3,
52.5, 49.3, 35.1, 18.9, 13.7 ppm. IR (KBr) d 3466, 2960, 1739, 1639,
1.2 Hz), 7.75 (1H, m), 7.52 (1H, t, J¼7.92 Hz), 6.41 (1H, s), 5.89 (1H, s),
1567, 1441, 1356, 1287, 1212, 1197, 1138, 1129, 1036, 982, 957 cmꢀ1
5.63 (1H, s), 3.75 (3H, s), 3.25 (1H, br s). 13C NMR (125 MHz, CDCl3)
(Yield 2d/3d¼71%).
d
166.2, 148.3, 143.7, 141.0, 132.8, 129.5, 126.9, 122.8, 121.7, 72.4,
52.3 ppm.
4.3.5. syn-Methyl 2-(1-hydroxy-3-methylbutyl)oxirane-2-
carboxylate 2d. 1H NMR (500 MHz, CDCl3)
d
3.92 (1H, dd, J¼3.8,
4.2.18. Methyl 2-((4-nitrophenyl)(hydroxy)methyl)acrylate 1r.18 1H
NMR (500 MHz, CDCl3)
9.2 Hz), 3.78 (3H, s), 3.12 (1H, d, J¼5.9 Hz), 2.98 (1H, d, J¼5.9 Hz),
d
8.18 (2H, d, J¼10.9 Hz), 7.56 (2H, d,
1.93e1.86 (1H, m),1.41e1.51 (2H, m), 0.95 (6H, t, J¼6.5 Hz). 13C NMR
J¼10.9 Hz), 6.38 (1H, s), 5.86 (1H, s), 5.62 (1H, m), 3.73 (3H, s), 3.32
(125 MHz, CDCl3)
21.4 ppm. IR (KBr)
d
d
170.0, 68.0, 58.5, 52.5, 49.6, 41.8, 24.4, 23.5,
3743, 2956, 2361, 1738, 1438, 1368, 1171, 1116,
(1H, br s). 13C NMR (125 MHz, CDCl3)
127.3, 127.2, 123.6, 72.7, 52.2 ppm.
d 166.4, 148.6, 143.7, 141.0,
1078, 994, 919, 864, 758 cmꢀ1. HRMS m/z calcd for C9H16O4Na
[MþNaþ]: 211.0946, found: 211.0942.
4.2.19. Methyl 2-(furan-2-yl(hydroxy)methyl)acrylate 1s.18 1H NMR
(500 MHz, CDCl3) 7.35 (1H, s), 6.37 (1H, s), 6.31 (1H, m), 6.24 (1H,
m), 5.93 (1H, s), 5.57 (1H, s), 3.74 (3H, s), 3.21 (1H, br s). 13C NMR
(125 MHz, CDCl3) 166.4, 154.1, 142.3, 143.7, 139.5, 126.7, 110.4,
107.1, 67.2, 52.0 ppm.
d
4.3.6. anti-Methyl 2-(1-hydroxy-3-methylbutyl)oxirane-2-
carboxylate 3d. 1H NMR (500 MHz, CDCl3)
d
4.20 (1H, dd, J¼3.8,
d
9.2 Hz), 3.77 (3H, s), 3.09 (1H, d, J¼5.9 Hz), 2.98 (1H, d, J¼5.9 Hz),
2.06e1.96 (1H, br s),1.76e1.82 (1H, m),1.48e1.51 (1H, m),1.27e1.35
(1H, m), 0.95 (6H, t, J¼6.5 Hz). 13C NMR (125 MHz, CDCl3)
d
170.0,
4.3. General experimental procedure for the epoxidation of
esters 1aes
67.5, 59.6, 52.5, 49.3, 42.0, 24.4, 23.5, 21.3 ppm. IR (KBr) d 3491,
2957, 2393, 1738, 1440, 1368, 1184, 1115, 1094, 993, 919, 879 cmꢀ1
.
To a ꢀ78 ꢁC cold THF (3.5 mL) was added TBHP (3.3 M in tolu-
ene) (2 mmol) and then methyllithium (1.6 M in hexanes)
(1.7 mmol). The resulting mixture was stirred at ꢀ78 ꢁC for 15 min
and then a solution of compound 1 (1 mmol) in THF (2 mL) was
added drop wise and then the mixture was left at ꢀ20 ꢁC (fridge)
for 20 h. Then solid Na2SO3 (120 mg) was added in one portion and
stirred for 15 min, then diluted with water and extracted with Et2O
(3ꢂ30 mL), the organic layers were washed (brine), dried (Na2SO4),
and concentrated. The crude oil was purified through chromatog-
raphy (silica-gel, hexanes/EtOAc (7:3) and (1:1)).
4.3.7. syn-Methyl 2-(cyclohexyl(hydroxy)methyl)oxirane-2-
carboxylate 2e. 1H NMR (500 MHz, CDCl3)
3.78 (3H, s), 3.39 (1H,
d
d, J¼6.7 Hz), 3.11 (1H, d, J¼5.9 Hz), 2.96 (1H, d, J¼5.9 Hz), 2.12 (1H,
br s), 1.88 (1H, m), 1.75e1.63 (5H, m), 1.26e1.03 (5H, m). 13C NMR
(125 MHz, CDCl3)
d
170.1, 75.1, 57.3, 52.4, 49.7, 41.2, 29.3, 28.2, 26.2,
3799, 2930, 2669, 2342, 1741, 1377, 1306,
26.0, 25.8 ppm. IR (KBr)
d
1200, 1124, 1087, 1030, 932, 761 cmꢀ1. HRMS m/z calcd for
C
11H18O4Na [MþNaþ]: 237.1103, found: 237.1105.
4.3.8. anti-Methyl 2-(cyclohexyl(hydroxy)methyl)oxirane-2-
carboxylate 3e. 1H NMR (500 MHz, CDCl3)
3.77 (3H, s), 3.69 (1H,
d
4.3.1. Methyl
2-(1-hydroxyethyl)oxirane-2-carboxylate
2a/3a.
d, J¼6.5 Hz), 3.02 (1H, d, J¼5.9 Hz), 2.97 (1H, d, J¼5.9 Hz), 1.94 (1H,
(Yield¼167 mg, 99%) (ratio of diastereomers 67/33). 1H NMR
m), 1.78e1.64 (5H, m), 1.30e0.94 (5H, m). 13C NMR (125 MHz,
(500 MHz, CDCl3)
d
4.33 (1H, q, J¼6.6 Hz) (minor), 4.16 (1H, q,
CDCl3)
15.1 ppm. IR (KBr)
1104, 1069, 1052, 974, 957 cmꢀ1
d
169.8, 74.5, 65.7, 58.7, 52.5, 49.6, 41.5, 29.6, 28.2, 26.1, 25.8,
J¼6.4 Hz) (major), 3.71 (3H, s), 3.10 (1H, d, J¼5.9 Hz) (major), 4.64
(1H, d, J¼6.1 Hz) (minor), 2.99 (1H, d, J¼6.0 Hz) (minor), 2.96 (1H, d,
J¼5.8 Hz) (major), 2.08 (1H, br s), 1.31 (3H, d, J¼6.4 Hz) (major), 1.29
d
3752, 2936, 2668, 2341, 1740, 1422, 1232, 1153,
.
(3H, d, J¼6.6 Hz) (minor). 13C NMR (125 MHz, CDCl3)
d
170.0 (mi-
4.3.9. syn-Methyl 2-(1-hydroxy-3-phenylpropyl)oxirane-2-
carboxylate 2f. 1H NMR (500 MHz, CDCl3)
7.33e7.20 (5H, m),
nor), 169.9 (major), 65.1 (major), 64.9 (minor), 59.6 (minor), 59.0
(major), 52.5 (major), 52.4 (minor), 49.3 (minor), 49.2 (major), 18.6
d
3.95 (1H, m), 3.77 (3H, s), 3.12 (1H, d, J¼6.0 Hz), 2.95 (1H, d,
(minor), 18.2 (major) ppm. IR (KBr) d 3932, 3839, 2984, 2363, 1738,
J¼6.0 Hz), 2.93e2.88 (1H, m), 2.77e2.65 (1H, m), 2.20e2.01 (1H,
1519, 1382, 1285, 1173, 1095, 971, 913, 853 cmꢀ1. HRMS m/z calcd for
C6H10O4Na [MþNaþ]: 169.0477, found: 169.0478.
m), 1.82e1.93 (1H, m). 13C NMR (125 MHz, CDCl3)
128.4, 126.1, 68.9, 58.3, 52.6, 49.3, 34.8, 31.7 ppm. IR (KBr)
d
170.0, 141.5,
3873,
3063, 3003, 2924, 2364,1748,1290, 1240,1132,1075, 754, 701 cmꢀ1
d
.
4.3.2. Methyl 2-(1-hydroxypropyl)oxirane-2-carboxylate 2b/3b.
(Yield¼128 mg, 70%) (ratio of diastereomers 76/24). 1H NMR
4.3.10. anti-Methyl 2-(1-hydroxy-3-phenylpropyl)oxirane-2-
carboxylate 3f. 1H NMR (500 MHz, CDCl3)
7.30e7.17 (5H, m),
(500 MHz, CDCl3)
d
3.75 (1H, m), 3.71 (3H, s), 3.12 (1H, d, J¼6.0 Hz),
d

A. Latorre et al. / Tetrahedron 70 (2014) 97e102
101
4.11 (1H, d, J¼9.3 Hz), 3.76 (3H, s), 3.05 (1H, d, J¼6.0 Hz), 3.00 (1H, d,
J¼6.0 Hz), 2.93e2.87 (1H, m), 2.75e2.69 (1H, m), 1.99e1.93 (1H, m),
(3H, m), 5.10 (1H, s), 3.73 (3H, s), 3.16 (1H, d, J¼6.0 Hz), 2.90 (1H, d,
J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
d
169.6, 140.6, 134.3, 129.6,
1.89e1.82 (1H, m),1.54 (1H, br s). 13C NMR (125 MHz, CDCl3)
d
170.0,
128.4, 127.1, 125.3, 71.3, 58.7, 52.8, 49.8 ppm. IR (KBr) d 3466, 3020,
141.3, 128.4, 126.0, 68.9, 59.1, 52.3, 49.3, 34.5, 31.8 ppm.
2964, 1736, 1463, 1264, 1154, 1170, 1083, 962, 918, 877 cmꢀ1
.
4.3.11. (E)-Methyl 2-(1-hydroxy-3-phenylallyl)oxirane-2-carboxylate
4.3.18. syn-Methyl 2-((2-chlorophenyl)(hydroxy)methyl)oxirane-2-
carboxylate 2n. 1H NMR (500 MHz, CDCl3)
7.54 (1H, m), 7.33
2g/3g. (Yield¼103 mg, 47%) (ratio of diastereomers 53/47). 1H
d
NMR (500 MHz, CDCl3)
d
7.40e7.24 (m, 5H), 6.74 (1H, d, J¼16.0 Hz)
(1H, m), 7.24e7.29 (2H, m), 6.04 (1H, s), 3.82 (3H, s), 3.06 (1H, d,
(major and minor), 6.27 (1H, dd, J¼6.3, 12.0 Hz) (major), 6.23 (1H,
dd, J¼5.8, 13.2 Hz) (minor), 4.85 (1H, dd, J¼6.3, 1.3 Hz) (minor), 4.71
(1H, dd, J¼6.5, 1.2 Hz) (major), 3.80 (3H, s) (major), 3.79 (3H, s)
(minor), 3.15 (1H, d, J¼5.9 Hz) (major), 3.13 (1H, d, J¼6.1 Hz) (mi-
nor), 3.06 (1H, d, J¼6.1 Hz) (minor), 3.00 (1H, d, J¼5.9 Hz) (major).
J¼6.0 Hz), 2.35 (1H, d, J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
d 169.9,
135.0, 132.9, 129.5, 127.9, 126.9, 67.9, 58.6, 52.9, 50.5 ppm. IR (KBr)
d
3741, 3019, 2938, 1734, 1472, 1390, 1297, 1195, 1064, 1028, 1028,
758, 741 cmꢀ1
.
13C NMR (125 MHz, CDCl3)
d
169.8 (minor), 169.7 (major), 136.2
4.3.19. syn-Methyl 2-((4-bromophenyl)(hydroxy)methyl)oxirane-2-
carboxylate 2o. 1H NMR (500 MHz, CDCl3)
7.48 (2H, d,
(minor), 136.1 (major), 133.5 (major), 133.1 (minor), 128.6, 128.1,
128.0, 126.7 (major and minor), 125.9 (minor), 125.6 (major), 70.7
(major), 70.0 (minor), 59.0 (minor), 58.5 (major), 52.7, 52.6 (major
and minor), 49.9 (major), 49.2 (minor) ppm. HRMS m/z calcd for
d
J¼8.0 Hz), 7.32 (2H, d, J¼8.0 Hz), 5.29 (1H, s), 3.73 (3H, s), 3.14 (1H,
d, J¼6.0 Hz), 2.88 (1H, d, J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
d
d
169.6, 137.5, 131.5, 129.0, 122.2, 71.2, 58.7, 52.7, 48.9 ppm. IR (KBr)
3711, 3077, 2957, 2360, 1923, 1592, 1728, 1460, 1333, 1286, 1196,
C
13H14O4Na [MþNaþ]: 257.0790, found: 257.0792.
1127, 1049, 935, 755 cmꢀ1. HRMS m/z calcd for C11H11BrO4Na
4.3.12. syn-Methyl 2-(hydroxy(phenyl)methyl)oxirane-2-carboxylate
[MþNaþ]: 308.9738, found: 308.9735.
2h.10 1H NMR (500 MHz, CDCl3)
d 7.43e7.30 (5H, m), 5.18 (1H, s),
3.73 (3H, s), 3.12 (1H, d, J¼5.9 Hz), 2.86 (1H, d, J¼5.9 Hz). 13C NMR
4.3.20. syn-Methyl 2-((2-nitrophenyl)(hydroxy)methyl)oxirane-2-
(125 MHz, CDCl3)
49.7 ppm. IR (KBr)
d
169.7, 138.4, 128.4, 127.0, 71.7, 59.0, 52.6,
carboxylate 2p. 1H NMR (500 MHz, CDCl3)
d
7.96 (1H, dd, J¼8.2,
d
3487, 3064, 2910, 2359, 1739, 1269, 1160, 1082,
1.3 Hz), 7.79 (1H, dd, J¼7.9, 1.3 Hz), 7.65 (1H, td, J¼7.7, 1.3 Hz), 7.48
1027, 947, 757 cmꢀ1. HRMS m/z calcd for C11H12O4Na [MþNaþ]:
(1H, td, J¼8.5,1.4 Hz), 6.17 (1H, s), 3.82 (3H, s), 3.13 (1H, d, J¼6.0 Hz),
231.0633, found: 231.0632.
2.37 (1H, d, J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
d
169.6, 148.3,
3648,
133.3, 129.8, 129.1, 124.6, 66.8, 58.1, 53.1, 51.0 ppm. IR (KBr)
d
4.3.13. syn-Methyl 2-(hydroxy(p-tolyl)methyl)oxirane-2-carboxylate
3093, 2957, 1725, 1440, 1357, 1267, 1200, 1156, 1053, 947, 747 cmꢀ1
.
2i. 1H NMR (500 MHz, CDCl3)
d
7.29 (2H, d, J¼8.0 Hz), 7.26 (2H, d,
J¼8.0 Hz), 5.15 (1H, s), 3.72 (3H, s), 3.11 (1H, d, J¼5.9 Hz), 2.86 (1H, d,
4.3.21. syn-Methyl 2-((3-nitrophenyl)(hydroxy)methyl)oxirane-2-
carboxylate 2q. 1H NMR (500 MHz, CDCl3)
8.33 (1H, m), 8.17
J¼5.9 Hz). 13C NMR (125 MHz, CDCl3)
d
169.8, 137.9, 135.5, 128.9,
3502, 3005, 2923,
d
127.0, 71.4, 59.1, 52.6, 49.6, 21.1 ppm. IR (KBr)
d
(1H, ddd, J¼8.2, 2.3,1.2 Hz), 7.81 (1H, m), 7.52 (1H, t, J¼7.92 Hz), 5.19
1743, 1197, 1125, 1020, 943, 837, 765, 686 cmꢀ1. HRMS m/z calcd for
(1H, s), 3.74 (3H, s), 3.22 (1H, d, J¼6.0 Hz), 2.95 (1H, d, J¼6.0 Hz). 13
C
C
12H14O4Na [MþNaþ]: 245.0790, found: 245.0787.
NMR (125 MHz, CDCl3) d 169.4, 148.2, 133.3, 129.2, 123.2, 122.1, 71.0,
65.7, 52.8, 49.7 ppm. IR (KBr)
d 3712, 3092, 3006, 2957, 2876, 1735,
4.3.14. syn-Methyl 2-(hydroxy(4-methoxyphenyl)methyl)oxirane-2-
carboxylate 2j. 1H NMR (500 MHz, CDCl3)
1441, 1353, 1289, 1163, 1096, 976, 935, 866, 758 cmꢀ1
.
d
7.33 (2H, d, J¼8.8 Hz),
6.87 (2H, d, J¼8.8 Hz), 5.16 (1H, s), 3.79 (3H, s), 3.67 (3H, s), 3.12 (1H,
4.3.22. syn-Methyl 2-((4-nitrophenyl)(hydroxy)methyl)oxirane-2-
carboxylate 2r. 1H NMR (500 MHz, CDCl3)
8.22 (2H, d,
d, J¼6.0 Hz), 2.85 (1H, d, J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
d
d
169.8, 159.5, 130.4, 128.5, 113.8, 71.2, 59.1, 55.2, 52.6, 49.5 ppm. IR
J¼8.0 Hz), 7.65 (2H, d, J¼8.0 Hz), 5.13 (1H, s), 3.73 (3H, s), 3.48 (1H,
(KBr)
d 3493, 3003, 2910, 1742, 1197, 1124, 1031, 978, 917, 836,
d, J¼6.0 Hz), 2.94 (1H, d, J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
756 cmꢀ1. HRMS m/z calcd for C12H14O5Na [MþNaþ]: 261.0739,
d
d
169.5, 146.0, 128.1, 127.8, 123.4, 71.4, 58.4, 53.0, 49.9 ppm. IR (KBr)
3902, 3087, 2958, 2342, 1925, 1715, 1517, 1442, 1221, 1096, 1053,
found: 261.0738.
946, 777 cmꢀ1. HRMS m/z calcd for C11H11NO6Na [MþNaþ]:
4.3.15. syn-Methyl 2-((4-fluorophenyl)(hydroxy)methyl)oxirane-2-
276.0484, found: 276.0482.
carboxylate 2k. 1H NMR (500 MHz, CDCl3)
d
7.40 (2H, dd, J¼8.5,
5.5 Hz), 7.03 (2H, t, J¼8.7 Hz), 5.15 (1H, s), 3.73 (3H, s), 3.13 (1H, d,
4.3.23. syn-Methyl 2-(furan-2-yl(hydroxy)methyl)oxirane-2-
J¼6.0 Hz), 2.85 (1H, d, J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
d
169.7,
carboxylate 2s. 1H NMR (500 MHz, CDCl3)
d 7.38 (1H, s), 7.26
162.2 (d, J¼245 Hz), 134.2, 129.0 (dd, J¼7.2, 21.3 Hz), 115.2 (dd,
(1H, s), 6.39 (1H, m), 6.33 (1H, m), 5.29 (1H, s), 3.75 (3H, s), 3.23
J¼12.5, 22.5 Hz), 71.1, 65.8, 52.7, 49.6 ppm. IR (KBr)
d
3477, 3070,
(1H, d, J¼6.0 Hz), 3.05 (1H, d, J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
2958, 2342, 1737, 1509, 1398, 1271, 1197, 1128, 1045, 980, 842,
756 cmꢀ1. HRMS m/z calcd for C11H11FO4Na [MþNaþ]: 249.0539,
found: 249.0535.
d
d
169.3, 125.6, 142.5, 110.4, 107.7, 64.5, 52.6, 49.0 ppm. IR (KBr)
3932, 3153, 3004, 2957, 1734, 1633, 1359, 1231, 1048, 975,
753 cmꢀ1
.
4.3.16. syn-Methyl 2-((4-chlorophenyl)(hydroxy)methyl)oxirane-2-
4.4. General experimental procedure for the preparation of
cyclic carbonates
carboxylate 2l. 1H NMR (500 MHz, CDCl3)
d
7.37 (2H, d, J¼8.0 Hz),
7.32 (2H, d, J¼8.0 Hz), 5.29 (1H, s), 3.73 (3H, s), 3.14 (1H, d,
J¼6.0 Hz), 2.88 (1H, d, J¼6.0 Hz). 13C NMR (125 MHz, CDCl3)
d
169.6,
An ice-bath cold suspension of sodium hydride (60% in mineral
oil) (1.12 mmol) in THF (1 mL) was treated with thiophenol
(2.25 mmol). The mixture was stirred at rt for 15 min and then
a solution of the epoxyester 2 (0.75 mmol) in THF (1 mL) was added
drop wise and the mixture was stirred at rt for 1.5 h. Then was
treated with pyridine (0.22 mmol) and triphosgene (0.48 mmol).
The mixture was refluxed for 15 h. Then brine was added and
extracted with Et2O (3ꢂ20 mL), the organic layers were washed
137.0, 134.1, 128.6, 128.5, 71.2, 58.7, 52.7, 49.7 ppm. IR (KBr)
d 3518,
3001, 2929, 1723, 1411, 1287, 1160, 1107, 1049, 982, 920, 756 cmꢀ1
.
HRMS m/z calcd for C11H11ClO4Na [MþNaþ]: 265.0244, found:
265.0245.
4.3.17. syn-Methyl 2-((3-chlorophenyl)(hydroxy)methyl)oxirane-2-
carboxylate 2m. 1H NMR (500 MHz, CDCl3)
d 7.44 (1H, s), 7.32

102
A. Latorre et al. / Tetrahedron 70 (2014) 97e102
(brine), dried (Na2SO4), and concentrated. The crude oil was puri-
fied through chromatography (silica-gel, hexanes/EtOAc (8:2) and
(7:3)).
25.0 ppm. IR (KBr)
930, 634 cmꢀ1
d 2934, 2854, 1747, 1584, 1584, 1440, 1178, 1052,
.
Acknowledgements
4.4.1. syn-Methyl 5-isobutyl-2-oxo-4-((phenylthio)methyl)-1,3-
dioxolane-4-carboxylate 4. 1H NMR (500 MHz, CDCl3)
d 7.46 (2H,
This work was financed by Bancaixa-UJI foundation (P11B2011-
m), 7.25e7.33 (3H, m), 4.73 (1H, m), 3.81 (3H, s), 3.58 (1H, d,
J¼15.0 Hz), 3.47 (1H, d, J¼15.0 Hz), 1.77 (1H, m), 1.44 (1H, m), 1.35
(1H, m), 0.92 (3H, d, J¼6.5 Hz), 0.84 (3H, d, J¼6.5 Hz). 13C NMR
59 and P1 1B2011-28). The authors also are grateful to the Serveis
ꢀ
Centrals d’Instrumentacio Científica (SCIC) of the Universitat Jaume
I for providing us with mass spectrometry and NMR.
(125 MHz, CDCl3)
d 167.7, 152.7, 134.7, 131.3, 129.3, 127.7, 86.6, 80.4,
53.2, 39.6, 38.6, 25.1, 23.0, 21.2 ppm. IR (KBr)
d 3059, 2959, 1811,
Supplementary data
1743, 1626, 1540, 1470, 1387, 1306, 1200, 1116, 1025, 968, 746 cmꢀ1
.
HRMS m/z calcd for C16H20O5SNa [MþNaþ]: 347.0929, found:
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.tet.2013.11.014.
347.0929.
4.4.2. anti-Methyl 5-isobutyl-2-oxo-4-((phenylthio)methyl)-1,3-
References and notes
dioxolane-4-carboxylate 5. 1H NMR (500 MHz, CDCl3)
d 7.46 (2H,
1. Chong, J. M.; Sharpless, K. B. Tetrahedron Lett. 1985, 26, 4683e4686.
2. Meth-Cohn, O.; Moore, C.; Taljaard, H. C. J. Chem. Soc., Perkin Trans. 1 1988,
2663e2674.
3. Saito, S.; Takahashi, N.; Ishikawa, T.; Moriwake, T. Tetrahedron Lett. 1991, 32,
667e670.
m), 7.25e7.33 (3H, m), 4.76 (1H, m), 3.70 (3H, s), 3.42 (2H, s), 1.71
(1H, m), 1.49 (1H, m), 1.47 (1H, m), 0.98 (3H, d, J¼6.5 Hz), 0.95 (3H,
d, J¼6.5 Hz). 13C NMR (125 MHz, CDCl3)
d 168.6, 152.2, 134.4, 131.9,
129.2, 127.8, 85.6, 80.4, 53.4, 37.9, 37.5, 24.9, 23.2, 21.2 ppm. IR (KBr)
4. Lanier, M.; Pastor, R. Tetrahedron Lett. 1995, 36, 2491e2492.
5. Righi, G.; Rumboldt, G.; Bonini, C. J. Org. Chem. 1996, 61, 3557e3560.
d
3059, 2959, 1806, 1749, 1582, 1439, 1360, 1257, 1132, 1048, 963,
744 cmꢀ1
.
ꢀ
6. Concellon, J. M.; Bardales, E. Org. Lett. 2002, 4, 189e191.
ꢀ
7. Concellon, J. M.; Bardales, E.; Llavona, R. J. Org. Chem. 2003, 68, 1585e1588 (and
refs cited therein).
4.4.3. syn-Methyl 5-cyclohexyl-2-oxo-4-((phenylthio)methyl)-1,3-
dioxolane-4-carboxylate 6. 1H NMR (500 MHz, CDCl3)
7.39 (2H,
ꢀ
ꢀ
8. Rodríguez, S.; Izquierdo, F.; Lopez, I.; Gonzalez, F. V. Tetrahedron 2006, 62,
11112e11123.
d
ꢀ
ꢀ
m), 7.25e7.17 (3H, m), 4.37 (1H, m), 3.73 (3H, s), 3.57 (1H, d,
J¼15.0 Hz), 3.35 (1H, d, J¼15.0 Hz), 1.80 (1H, m), 1.40e1.77 (5H, m),
9. Lopez, I.; Izquierdo, J.; Rodríguez, S.; Gonzalez, F. V. J. Org. Chem. 2007, 72,
6614e6617.
ꢀ
10. Bailey, M.; Marko, I. E.; Ollis, W. D.; Rasmussen, P. R. Tetrahedron Lett. 1990, 31,
1.24e0.79 (5H, m). 13C NMR (125 MHz, CDCl3)
d 168.9, 152.4, 134.8,
4509e4512.
131.9, 129.2, 127.8, 86.0, 85.7, 53.5, 37.7, 37.3, 29.5, 28.1, 25.7, 25.4,
ꢀ
11. Bailey, M.; Staton, I.; Ashton, P. R.; Marko, I. E.; Ollis, W. D. Tetrahedron: Asym-
metry 1991, 2, 495e509.
25.1 ppm. IR (KBr)
d 3060, 2929, 2857, 1741, 1582, 1402, 1195, 1024,
12. Svenda, M.; Myers, A. G. Org. Lett. 2009, 11, 2437e2440.
13. Yu, C.; Liu, B.; Hu, L. J. Org. Chem. 2001, 66, 5413e5418.
14. García-Ruano, J. L.; Fajardo, C.; Fraile, A.; Martí, M. R. J. Org. Chem. 2005, 70,
4300e4306.
927, 845, 713, 629 cmꢀ1. HRMS m/z calcd for C18H22O5SNa
[MþNaþ]: 373.1086, found: 373.1089.
15. Adam, W.; Braun, M.; Griesbek, A.; Lucchini, V.; Staab, E.; Will, B. J. Am. Chem.
Soc. 1989, 111, 203e212.
4.4.4. anti-Methyl 5-cyclohexyl-2-oxo-4-((phenylthio)methyl)-1,3-
dioxolane-4-carboxylate 7. 1H NMR (500 MHz, CDCl3)
d 7.47 (2H,
16. Lee, K.; Loh, T. Chem. Commun. 2006, 4209e4211.
17. Brzezinski, L. J.; Rafel, S.; Leahy, J. W. Tetrahedron 1997, 53, 16423e16434.
18. Mi, X.; Luo, S.; Cheng, J. J. Org. Chem. 2005, 70, 2338e2341.
19. Aggarwal, V. A.; Emme, I.; Fulford, S. Y. J. Org. Chem. 2003, 68, 692e700.
20. Guo, Y.; Shao, G.; Li, L.; Wu, W.; Li, R.; Li, J.; Song, J.; Qiu, L.; Prashad, M.; Kwong,
F. Y. Adv. Synth. Catal. 2010, 352, 1539e1553.
m), 7.24e7.33 (3H, m), 4.43 (1H, m), 3.76 (3H, s), 3.56 (1H, d,
J¼15.0 Hz), 3.48 (1H, d, J¼15.0 Hz), 1.77 (1H, m), 1.68e1.76 (5H, m),
1.10e1.25 (5H, m). 13C NMR (125 MHz, CDCl3)
d 167.9, 152.6, 134.7,
131.7, 129.2, 127.7, 86.6, 85.8, 53.3, 40.8, 38.6, 28.6, 28.5, 25.7, 25.2,