Resolution of racemic 3-aryloxy-1-nitrooxypropan-2-ols by lipase-catalyzed enantioselective acetylation

Article abstract of DOI:10.1016/S0957-4166(01)00378-0

Both (R)- and (S)-enantiomers of 3-aryloxy-1-nitrooxypropan-2-ols (R)-(-)-1, (S)-(+)-2 were prepared in high enantiomeric excess by lipase from Pseudomonas cepacia (Amano PS) or Pseudomonas fluorescens (Amano AK)-catalyzed acetylation of racemic alcohols 1a-g with vinyl acetate in n-hexane at 4 or 22°C. The enantioselectivity of this transformation was dependent on the substitution pattern of the aryl ring with E-values ranging from 31 to 111.

Full text of DOI:10.1016/S0957-4166(01)00378-0

TETRAHEDRON:
ASYMMETRY
Pergamon
Tetrahedron: Asymmetry 12 (2001) 2109–2119
Resolution of racemic 3-aryloxy-1-nitrooxypropan-2-ols by
lipase-catalyzed enantioselective acetylation
Beata Krystyna Pchelka,a,b,* Andre´ Loupy,a Jan Plenkiewicz,b Alain Petita and Luis Blancoc
aLaboratoire des Re´actions Se´lectives sur Supports (CNRS UMR 8615), Institut de Chimie Mole´culaire d’Orsay, Baˆt. 410,
Universite´ de Paris-Sud, 91405 Orsay Cedex, France
bFaculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
cLaboratoire des Carbocycles (CNRS UMR 8615), Institut de Chimie Mole´culaire d’Orsay, Baˆt. 420, Universite´ de Paris-Sud,
91405 Orsay Cedex, France
Received 30 May 2001; accepted 23 August 2001
Abstract—Both (R)- and (S)-enantiomers of 3-aryloxy-1-nitrooxypropan-2-ols (R)-(−)-1, (S)-(+)-2 were prepared in high
enantiomeric excess by lipase from Pseudomonas cepacia (Amano PS) or Pseudomonas fluorescens (Amano AK)-catalyzed
acetylation of racemic alcohols 1a–g with vinyl acetate in n-hexane at 4 or 22°C. The enantioselectivity of this transformation was
dependent on the substitution pattern of the aryl ring with E-values ranging from 31 to 111. © 2001 Elsevier Science Ltd. All
rights reserved.
1. Introduction
the large group of drugs termed nitrovasodilators.5 At
present, some nitrovasodilators such as nitroglycerin,6
isosorbide dinitrate7 and nicorandil8 are clinically useful
drugs (Fig. 1).
Chiral 1,3-disubstituted secondary propanols are
known as useful building blocks in the synthesis of
biologically active compounds such as b-blockers,
antidepressant drugs and muscle relaxants.1 A number
of racemic mixtures of these compounds carrying vari-
ous substituents has been resolved by an enzyme-cata-
lyzed kinetic method. Most frequently2 compounds
substituted on the phenyl ring and with halogen,
amino, hydroxy or carboxyl substituents on the propyl
chain were investigated.
Organic nitrates and nitroglycerin (glyceryl trinitrate)
have been mainstays of cardiovascular therapy9 for
many years and are of particular benefit in the treat-
ment of angina pectoris attacks,10 unstable angina11
and early stages of acute myocardial infaction.12 They
have shown real efficacy in the presence of coronary
atherosclerosis, hypercholesterolemia, and other associ-
ated vessel wall disorders involving endothelial
dysfunction13 and disordered vasodilatory capacity of
the coronary arteries.13,5
In continuation of our interest in the lipase-catalyzed
resolutions of various 1,3-disubstituted secondary
propanols3,4 we focussed our attention on 3-aryloxy-1-
nitrooxypropan-2-ols 1 which are expected to be poten-
tially active cardiovascular agents similar to those from
Studies with isoidide dinitrate14 and glyceryl-1-nitrate15
(products of the metabolic denitration of nitroglycerin16)
Figure 1.
* Corresponding author. Tel.: +33(0)1-69157256; fax: +33(0)1-69154679; e-mail: pbeata@icmo.u-psud.fr
0957-4166/01/$ - see front matter © 2001 Elsevier Science Ltd. All rights reserved.
PII: S0957-4166(01)00378-0

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B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
have shown that organic nitrates may be subject to
enantiospecific differences in their pharmacological
effects. It was therefore of interest to prepared 3-aryl-
oxy-1-nitrooxypropan-2-ols 1 in enantiomerically pure
form for future characterization of their pharmacologi-
cal properties in different in vitro and animal models.
As a part of our continuing interest, we undertook the
present detailed study, investigating the influence of
several parameters in an attempt to improve the
enantioselectivity.
2. Results and discussion
The 3-aryloxy-1-nitrooxypropan-2-ols 1 are direct pre-
cursors of 3-aryloxy-1,2-propanediols 5 by hydrolysis17
or hydrogenation18 of the nitrate group of 1 (Fig. 2).
2.1. Synthesis of 3-aryloxy-1-nitrooxypropan-2-ols ( )-
1a–g
The 1,2-diol functionality is involved in various
synthetic19 and pharmaceutical20 intermediates as well
as in commercial medicines. For instance, enantiomeri-
cally pure 3-aryloxy-1,2-propanediols 5 are of interest
as antifungal agents, e.g. Chlorphenesin (Ar=4-Cl-
C6H4-),21 muscle relaxants such as Mephenesin (Ar=2-
CH3-C6H4-),20a,21a–c,22 and Guaifenesin (Ar=2-CH3O-
C6H4-)2a,21a–c,22b,23 as well as intermediates in the syn-
thesis of b-blockers20a,24 They can also be used as chiral
ligands25 in transition metal complexes, and as building
blocks in the synthesis of crown ethers.26 Several 1,2-
propanediols after conversion into carbamates 6 were
tested as muscle relaxants, analgesic agents and tran-
quilizers, e.g. chlorphenesin carbamate. It is well estab-
lished that in the case of compounds 5 the desirable
therapeutic activities belong mainly to the (S)-enan-
tiomers.21–23 In connection with the importance of this
class of compounds, several methods have been
reported for their synthesis.27–35 The ready hydrolysis
and hydrogenation of nitrooxy group suggests that
preparation of optically active 3-aryloxy-1-nitrooxy-
propan-2-ols ( )-1a–g could provide an easy alterna-
tive route to the corresponding (S)- and (R)-1,2-diols
5a–g.
Various synthetic approaches have been tested to pre-
pare the racemic 3-aryloxy-1-nitrooxypropan-2-ols ( )-
1.36 Among them, the ring-opening of appropriate
arylglycidyl ethers 3a–g with ammonium nitrate in the
presence of ceric ammonium nitrate (CAN) in acetoni-
trile–water solution (6:1 v/v) has been found to be the
most efficient one37 (Scheme 1). The latter were previ-
ously prepared in high yields by Williamson reaction
from the corresponding phenols 4a–g and epichlorhy-
drin under solvent-free phase transfer catalysis condi-
tions coupled with microwave (MW) activation.38
2.2. Kinetic resolution of ( )-1a–g by lipase-catalyzed
transesterification
The conditions for the lipase-catalyzed acetylation of
racemic nitrooxy alcohols ( )-1 were optimized accord-
ing to the conventional method described in the
literature39 (Scheme 2). The effects of lipase, solvent,
acyl donor, temperature, additive (e.g. triethylamine,
crown ethers and thiacrown ethers) and substituent on
the aromatic ring on the enantioselectivity of enzymatic
acetylation were evaluated on reactivity and selectivity
by determination of the enantiomeric ratio (E).
Recently, our group reported some preliminary results3
on the kinetic resolution of various ring-substituted
racemic nitrooxy alcohols 1 by acetylation in the pres-
ence of lipase from Pseudomonas fluorescens (Amano
AK). However, poor enantioselectivities (E=7–17)
were obtained, except for Ar=3-CH3-C6H4- (E=60).
The efficiency of different commercially available
lipases to catalyze the acylation reaction was investi-
gated. For this purpose, ( )-1a, taken as a model
substrate, was allowed to react with 3 equiv. of vinyl
acetate in the presence of different lipases in tert-butyl
Figure 2.
Scheme 1.

B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
2111
Scheme 2.
methyl ether at 22°C. In control experiments, it was
shown that the reaction did not proceed in the absence
of enzyme. Generally, the transesterifications were
stopped after 40–60% conversion. Removing the
enzyme by filtration to give a mixture of enantiomeri-
cally enriched acetate 2a and unreacted alcohol 1a. The
enantiomeric excesses of 1a and 2a were determined by
HPLC using a chiral column. The absolute configura-
tions of the products, alcohol 1a and acetate 2a were
determined by comparison of their chiroptical and
chromatographic properties with authentic samples,
prepared by the method described in our previous
paper.3 The unreacted alcohol 1a and its acetate 2a had
the (R)-(−) and (S)-(+) configuration, respectively.
Additionally, the absolute configuration of unreacted
alcohol 1a was supported by correlation to authentic
(S)-(+)-3-phenoxy-1,2-propanediol 5a.18,33a This assign-
ment agrees well with the Kazlauskas-rule.39
Among the tested lipases, only Pseudomonas cepacia
(Amano PS (E=17) and Amano PS immobilized on
diatomite (E=20)) as well as P. fluorescens (Amano
AK (E=16)) exhibited promising enantioselectivities
for this substrate. Rather similar enantioselectivities
(E=10–14) were obtained with lipase from Burkholde-
ria cepacia formerly P. cepacia (Chirazyme® L-1, lyo.
and immobilized Chirazyme® L-1, c.-f., lyo.) and lipase
from Candida antarctica, fraction B (immobilized Chi-
razyme® L-2, c.-f., lyo., Chirazyme® L-2, c.-f., C2, lyo.,
Chirazyme® L-2, c.-f., C3, lyo. and Novozym® SP 435).
The other examined lipases showed poor selectivities or
reactivities.
We then investigated the proper choice of solvent. Its
influence on the enantioselectivity in enzyme-catalyzed
transesterifications is well documented, but for a new
substrate type it is difficult to anticipate the best
choice.19a,41,42 The attempts were undertaken to find the
correlation between enantioselectivity and physico-
chemical characteristics of the solvent such as hydro-
phobicity or dielectric constant.43
The results presented in Table 1 show that for most of
the tested lipases the (R)-(−)-alcohol 1a reacts slower
than the (S)-(+) enantiomer and the reactions show
poor to moderate enantioselectivities (E=3–20).
Table 1. Kinetic resolutions of (9)-1a by lipase-catalyzed acetylation with vinyl acetate in tert-butyl methyl ether at 22°Ca
Lipasesd
Amount of lipase Time (h)
(mg)
Conv. (%)b
Alcohol (R)-(−)-1a e.e.s
Ester (S)-(+)-2a e.e.p
Eb
(%)c
(%)c
Amano AK [B]
Amano PS [A]
Amano PS on diatomite
Chirazyme® L-1, lyo.
Chirazyme® L-1, c.-f., lyo.
Novozym® SP 435
180
180
120
5.6
200
50
50
50
50
200
10
100
50
200
200
100
80
26
28
28
9
16
28
18
27
22
40
43
58
48
63
49
34
32
35
30
4
51
53
23
4
39
0
55
61
95
61
94
70
38
36
42
Rac.
–
52
31
11
–
45
–
81
80
70
66
56
73
75
76
77
Rac.
–
51
28
36
–
70
–
16
17
20
10
12
14
10
11
12
1
–
5
3
3
–
8
–
Chirazyme® L-2, c.-f., lyo.
Chirazyme® L-2, c.-f., C2, lyo.
Chirazyme® L-2, c.-f., C3, lyo.
Chirazyme® L-3, lyo.
Chirazyme® L-3, purified, lyo.
Chirazyme® L-5, lyo.
Chirazyme® L-6, lyo.
Chirazyme® L-7, lyo.
Chirazyme® L-8, lyo.
Chirazyme® L-10, lyo.
Chirazyme® L-12, lyo.
312
312
72
21
312
312
18
312
a Conditions: ( )-1a (213 mg, 1 mmol), vinyl acetate (258 mg, 3 mmol) and tert-butyl methyl ether (10 mL).
b Conversions and E-values were calculated from the enantiomeric excess of substrate 2 (e.e.s) and of product 3 (e.e.p) using the usual formula:
E=ln[(1−e.e.s)(e.e.p/(e.e.s+e.e.p))]/ln[(1+e.e.s)(e.e.p/(e.e.s+e.e.p))], conv.=e.e.s/(e.e.s+e.e.p); according to Ref. 40.
c Determined by chiral HPLC analysis using Pharmachir 4 C (1/4×250 mm) column.
d Amano AK (P. fluorescens) [B]; Amano PS [A] and Amano PS immobilized on diatomite (P. cepacia); Chirazyme® L-1, lyo. and immobilized
Chirazyme® L-1, c.-f., lyo. (B. cepacia, formerly P. cepacia); immobilized Chirazyme® L-2, c.-f., lyo., Chirazyme® L-2, c.-f., C2, lyo. and
Chirazyme® L-2, c.-f., C3, lyo. and Novozym® SP 435 (C. antarctica, fraction B); Chirazyme® L-3, lyo. and Chirazyme® L-3, purified, lyo. (C.
rugosa, formerly C. cylindracea); Chirazyme® L-5, lyo. (C. antarctica, fraction A); Chirazyme® L-6, lyo. (Pseudomonas species); Chirazyme® L-7,
lyo. (porcine pancreas lipase); Chirazyme® L-8, lyo. (Thermomyces species, formerly Humicola species); Chirazyme® L-10, lyo. (Alcaligines
species) and Chirazyme® L-12, lyo. (lipase from thermophilic microorganism).

2112
B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
Next, the influence of the amount of P. cepacia lipase
(Amano PS) on the reaction rate and enantioselectivity
was investigated. The reaction of ( )-1a was carried out
with vinyl acetate in n-hexane at 22°C. It appears
clearly from Table 3 that use of enzyme in the amounts
ranging from 50–180 mg/mmol of substrate (entries
1–3) results in good conversions (37–51%) in reasonable
times (17–39 h) without significant changes in enan-
tioselectivity (E=48–57). Further decreasing the
amount of enzyme to 10–25 mg/mmol of substrate
(entries 4 and 5) led to only a slight decrease of the
enantioselectivity (E=42–43) but the reaction pro-
ceeded with slower rate (42–44% of conversion within
56–67 h).
Acetylations of ( )-1a with vinyl acetate at 22°C in the
presence of lipase from P. cepacia (Amano PS) or P.
fluorescens (Amano AK) were performed in organic
solvents frequently used in this type of reaction. The
main results are given in Table 2 and Fig. 3.
It is obvious from Table 2 that alteration of the solvent
caused significant changes in the enantioselectivity and
reaction rate in comparison with tert-butyl methyl ether
as the standard solvent. Among the tested solvents,
n-hexane gave the best result with regard to enantiose-
lectivity (E=57) and reaction rate (17 h for 49% con-
version). Enantioselectivities in toluene, dichloro-
methane as well as in solvent-free condition were simi-
lar in all cases (E=41, 42, 40 respectively) and slightly
lower than in n-hexane. On the other hand, in toluene
as well as in dichloromethane the reactions rates were
significantly lower (46 h for 45% conversion and 120 h
for 38% conversion, respectively) in comparison to
n-hexane and solvent-free conditions. Fig. 3 shows the
course of the conversion of ( )-1a in selected solvents
and in solvent-free conditions with time. It is important
to note that acetylation in solvent free-conditions was
rather difficult to reproduce (reaction time ranging
from 16–28 h for 31–35% conversion). In general,
enzyme selectivity was good enough for practical use in
all of the tested solvents (E=24–57) except tert-butyl
methyl ether (E=17) and acetonitrile (E=12). Chang-
ing the enzyme from P. cepacia lipase (Amano PS) to
P. fluorescens (Amano AK) in n-hexane (entries 3 and
4) did not alter the reaction rate considerably, but led
to a noticeable decrease in the enantioselectivity (E
decreased from 57 to 47). For reactions completed in
toluene (entries 6 and 7) and tert-butyl methyl ether
(entries 8 and 9) the reaction rates and enantioselectivi-
ties were similar for both lipases. Thus, we selected
n-hexane as the solvent for further optimization of the
reaction.
The effect of the acyl donor structure on the enantiose-
lectivity of lipase-catalyzed transesterification reaction
Figure 3. Conversion versus time for P. cepacia (Amano PS)
[A] lipase-catalyzed transesterification of vinyl acetate with
( )-1a at 22°C in selected solvents.
Table 2. Transesterification of vinyl acetate with (9)-1a in various solventsa
Entry
Lipasea
Solvent
Log P
Time (h)
Conv.b (%)
Alcohol (R)-(−)-1a e.e.s
Ester (S)-(+)-2a e.e.p
Eb
(%)c
(%)c
1
2
3
4
5
6
7
8
A
B
A
B
A
A
B
A
B
A
A
A
A
A
None
None
−
−
3.5
3.5
3.2
2.5
2.5
1.3
1.3
18
22
17
22
17
46
36
28
26
120
120
120
96
35
31
49
41
36
45
30
43
40
38
25
33
30
27
50
43
87
64
50
72
39
61
55
56
30
44
34
33
91
93
90
92
89
90
93
80
81
92
91
88
79
91
40
42
57
47
29
41
40
17
16
42
29
24
12
30
n-Hexane
n-Hexane
Cyclohexane
Toluene
Toluene
tBuOMe
tBuOMe
CH2Cl2
THF
9
10
11
12
13
14
0.6
0.49
−0.23
−0.33
−1.1
Acetone
Acetonitrile
Dioxane
120
a Conditions: ( )-1a (213 mg, 1 mmol), vinyl acetate (258 mg, 3 mmol), lipase from P. cepacia (Amano PS) [A] or P. fluorescens (Amano AK)
[B] (180 mg) and solvent (10 mL) at 22°C.
b See Table 1.
c See Table 1.

B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
2113
Table 3. Influence of the amount of P. cepacia lipase (Amano PS) [A] on the transesterification of vinyl acetate with
(9)-1aa
Entry
Amount of lipase (mg)
Time (h)
Conv.b (%)
Alcohol (R)-(−)-1a e.e.s (%)c
Ester (S)-(+)-2a e.e.p (%)c
Eb
1
2
3
4
5
180
90
50
25
10
17
29
39
56
67
49
37
51
42
44
87
55
92
66
71
90
94
87
91
90
57
53
48
43
42
a Conditions: ( )-1a (213 mg, 1 mmol), vinyl acetate (258 mg, 3 mmol), lipase from P. cepacia (Amano PS) [A] (10–180 mg) and n-hexane (10 mL)
at 22°C.
b See Table 1.
c See Table 1.
has been well documented by Ema et al.44 Generally,
among the various types of acyl donors examined, enol
esters are considered to be the most suitable for kinetic
resolution by transesterification due to their high reac-
tivity and reaction irreversibility.45 Recently,4 we found,
that enol esters such as vinyl acetate and iso-propenyl
acetate were appropriate acyl donors for the enzymatic
acetylation of some azido alcohols. Thus, in order to
enhance the enantioselectivity of lipase-catalyzed acetyl-
ation of ( )-1a in n-hexane at 22°C, four various enol
esters were examined using P. cepacia (Amano PS) or
P. fluorescens lipase (Amano AK) as catalysts (Scheme
3).
49 and 47% conversions, respectively) were obtained
when acetylations of ( )-1a catalyzed by P. cepacia
lipase (Amano PS) were carried out with vinyl or
iso-propenyl acetate. On the other hand, as can be seen
from the conversion versus time curves in Fig. 4(a),
changing the lipase from P. cepacia (Amano PS) to P.
fluorescens (Amano AK) in the acetylation performed
with iso-propenyl acetate considerably prolonged the
reaction time (29 h for 24% conversion) making this
approach synthetically useless in spite of the high enan-
tiomeric ratio (E=52). Finally, it is interesting to note
that lengthening the alkyl chain of the vinyl esters
produces a significant decrease in the reaction rate
(conversion ranging from 22 to 49% in 17–24 h) but
only a marginal effect on the enantioselectivity of this
reaction (E=49–57). Similar effects were also observed
As shown in Table 4 and Fig. 4(a), the highest reaction
rates and enantioselectivities (E=57 and 66 in 17 h for
Scheme 3.
Table 4. P. cepacia (Amano PS) [A] or P. fluorescens (Amano AK) [B] lipase-catalyzed acetylation of (9)-1a by use of
various enol estersa
Enol ester
Lipasea
R
X
Time (h)
Conv.b (%)
Alcohol (R)-(−)-1a e.e.s
(S)-(+)-Ester e.e.p
Eb
(%)c
(%)c
Vinyl acetate
Vinyl acetate
Vinyl acetate
Vinyl acetate
Vinyl acetate
Vinyl acetate
Vinyl acetate
Vinyl acetate
Vinyl
A
A
A
A
A
A
A
B
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CH3
CHꢀCH2
CHꢀCH2
CHꢀCH2
CHꢀCH2
CHꢀCH2
CHꢀCH2
CHꢀCH2
CHꢀCH2
4
9
12
33
49
54
56
60
66
41
22
15
47
87
98
99
99
99
64
27
2a, 97
2a, 95
2a, 90
2a, 84
2a, 77
2a, 65
2a, 50
2a, 92
7a, 95
76
63
57
53
39
23
14
47
51
17
25
31
40
50
22
28
A
C4H9 CHꢀCH2
pentanoate
Vinyl hexanoate
iso-Propenyl
acetate
iso-Propenyl
acetate
A
A
C5H11 CHꢀCH2
42
17
39
47
59
98
8a, 94
2a, 87
49
66
CH3
C(CH3)ꢀCH2
C(CH3)ꢀCH2
B
CH3
29
24
30
2a, 95
52
a Conditions: ( )-1a (213 mg, 1 mmol), enol ester (258 mg, 3 mmol), lipase from P. cepacia (Amano PS) [A] or P. fluorescens (Amano AK) [B]
(180 mg) and n-hexane (10 mL) at 22°C.
b See Table 1.
c See Table 1.

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B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
Figure 4. (a) Conversion versus time for Amano PS [A] and Amano AK [B] lipase-catalyzed acetylation of ( )-1a with selected
enol esters; (b) dependance of enantiomeric purities of 1a and 2a on the conversion of ( )-1a in Amano PS lipase-catalyzed
acetylation with vinyl acetate in n-hexane at 22°C.
in the kinetic resolution of some 1-azido-3-aryloxy-2-
propanols4 with lipase from C. antarctica-B
(Novozym® SP 435).
from the curves, the product (S)-2a is obtained in its
highest yield and enantiomeric purities at 30–40% con-
version (e.e. of 2a=95–98%). In the case of unreacted
alcohol (R)-1a the enantiomeric purity remains low
before 50% conversion and reaches its maximum (e.e.
of 1a=95–99%) beyond the 50–60% conversion mark.
In order to investigate whether the enantioselectivity of
P. cepacia lipase-catalyzed acetylation of ( )-1a with
vinyl acetate in n-hexane at 22°C changes during the
reaction time we measured the enantiomeric purities of
the products (R)-1a and (S)-2a over time. The depen-
dence of the enantiomeric purities of the alcohol and
acetate products on the conversion in this reaction is
presented in Table 4 and Fig. 4(b).
We recently found that use of some additives such as
triethylamine,46 crown47 and thiacrown ethers48 as well
as TDA-147c enhanced both enantioselectivity and reac-
tion rate in transesterification with 1-azido-3-phenoxy-
2-propanol catalyzed by Novozym® SP 435.4 Therefore,
in the next step, the influence of triethylamine, 15-
crown-5 and 18-crown-6 ethers, 1,4,8,11-tetrathia-
cyclotetradecane (TTCTD), 1,5,9,13-tetrathiacyclo-
hexadecane-3,11-diol (TTCHD-D), and tris-(3,6-dioxa-
heptyl)amine (TDA-1) were screened for the P. cepacia
lipase-catalyzed acetylation of ( )-1a with vinyl acetate
in n-hexane at 22°C. The main results are presented in
Table 5.
The results in Table 4 and Fig. 4(b) show that for this
reaction E decreases over time. In fact, if the conver-
sion of ( )-1a is increased from 12 to 54% the E-value
decreased from 76 to 53. Further increase in the conver-
sion induced significant decreases in the enantiomeric
ratio for the reaction (E ranging from 39 to 14 for 56
and 66% conversions, respectively). As can be seen
Table 5. Additive effects on the acetylation of (9)-1a with vinyl acetate using P. cepacia lipase (Amano PS) in n-hexane at
22°Ca
Entry
Additive
Amount of additive Time (h)
(mg)
Conv. (%)b
Alcohol (R)-(−)-1a e.e.s
Ester (S)-(+)-2a e.e.p
Eb
(%)c
(%)c
1
2
3
4
5
6
7
None
NEt3
–
20
20
22
14
12
12
17
19
22
17
19
20
20
49
53
23
17
24
35
38
87
93
28
20
30
50
57
90
82
94
95
94
93
94
57
35
41
47
43
45
49
15-Crown-5
18-Crown-6
TDA-1d
TTCTDd
TTCHD-Dd
a Conditions: ( )-1a (213 mg, 1 mmol), vinyl acetate (258 mg, 3 mmol), lipase from P. cepacia (Amano PS) (180 mg), 14 mol% of triethylamine
or 5 mol% additive and n-hexane (10 mL) at 22°C.
b See Table 1.
c See Table 1.
d TDA-1, tris-(3,6-dioxaheptyl)amine; TTCTD, 1,4,8,11-tetrathiacyclotetradecane; TTCHD-D, 1,5,9,13-tetrathiacyclohexadecane-3,11-diol.

B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
2115
Finally, in order to investigate the influence of the
substituent (Ar) at the aryl ring, 6 different racemic
3-aryloxy-1-nitrooxypropan-2-ols ( )-1b–g were used as
substrates in a kinetic resolution by a lipase-catalyzed
acetylation.
It is obvious from Table 5 that the use of these addi-
tives in acetylation of ( )-1a has a negative effect on
both the enantioselectivity and the rate of the reaction.
Without additive the reaction proceeded with higher
enantioselectivity (E=57) giving a good conversion in
reasonable time (49% conversion in 17 h). The addition
of triethylamine markedly decreased the enantiomeric
ratio (E=35) without any change in reaction rate (53%
conversion in 19 h). On the other hand, addition of
crown ethers (15-5, 18-6) and thiacrown ethers
(TTCTD, TTCHD-D) as well as TDA-1 significantly
increased the reaction time (17–38% of conversion
within 17–22 h) but has only a slight effect on the
enantioselectivity of the reaction (E=41–49).
All acetylations of ( )-1a–g were carried out in n-hex-
ane with vinyl acetate using P. cepacia (Amano PS) [A]
lipase at 22 and 4°C. In the cases of racemic alcohols
( )-1a, ( )-1d and ( )-1f, lipase from P. fluorescens
(Amano AK) [B] was used at 22°C. The results are
collected in Table 7.
The enantiomeric excesses of the unreacted alcohol
1b–g and the acetate product 2b–g were determined by
chiral HPLC analysis. To our knowledge, no data are
available for the absolute configurations of 1b–g and
2b–g or their derivatives. For these compounds the
absolute configurations were assigned by comparison of
the sign of the specific rotation with the data for
(R)-(−)-1a and (S)-(+)-2a. In all cases the unreacted
alcohols 1b–g, and their acetates 2b–g had the (R)-(−)
and (S)-(+) configurations, respectively.
Sakai et al.49 have recently reported that the enantiose-
lectivity of P. cepacia lipase for substrates like azirine-
2-methanol is significantly increased by lowering the
temperature. Consequently, we have investigated the P.
cepacia lipase-catalyzed acetylation of ( )-1a under the
conditions described in Table 5 at temperatures ranging
from 22 to −18°C (Table 6).
It can be clearly seen from Table 7 that it is possible to
run the acetylation of racemic alcohols ( )-1a–g with
good enantioselectivities (E=31–111) whatever the sub-
stituents on the phenyl ring are. However, it is impor-
tant to note that the substrates with ortho-substituents
(1b, 1e and 1f) show significantly slower reaction rates
and slightly lower enantiomeric excess.
The results in Table 6 show that lipase from P. cepacia
(Amano PS) remains active even at −18°C. Lowering of
the temperature from 22 to −18°C enhances the lipase
enantioselectivity (E-value increased from 57 at 22°C to
105 at −18°C) but decreases the reaction rate (27%
conversion in 140 h at −18°C). An acceptable reaction
time was obtained at −18°C by increasing the amount
of lipase from 180 mg/mmol of substrate to 600 mg/
mmol (entry 4). Reducing the temperature further to
−30°C results in a significant decrease of the reaction
rate (only 10% of conversion within 18 days). From
these experiments it appears that temperatures between
4 and 22°C are good compromise for achieving the
preparation of both (R)-1a and (S)-2a in terms of
enantioselectivity and reaction time. Moreover at 22°C
the enantiomeric ratio is also sufficiently high for prac-
tical use.
3. Conclusion
In summary, we have presented a general method to
realize enantioselective acetylations of 3-aryloxy-1-
nitrooxypropan-2-ols 1a–g whatever the aromatic sub-
stituents are. High enantioselectivities (E=31–111)
were obtained using P. cepacia (Amano PS) or P.
fluorescens (Amano AK) lipase and vinyl acetate in
n-hexane at 22 or 4°C.
Table 6. Temperature influence in the P. cepacia lipase-catalyzed acetylation of (9)-1aa
Entry
Temp. (°C)
Amount of lipase Time (h)
(mg)
Conv. (%)b
Alcohol (R)-(−)-1a e.e.s
Ester (S)-(+)-2a e.e.p
Eb
(%)c
(%)c
1
2
3
4
22
4
−18
−18
180
180
180
600
17
65
140
68
49
49
27
48
87
90
36
87
90
93
97
94
57
94
105
96
a Conditions: ( )-1a (213 mg, 1 mmol), vinyl acetate (258 mg, 3 mmol), lipase from P. cepacia (Amano PS) and n-hexane (10 mL).
b See Table 1.
c See Table 1.

2116
B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
Table 7. Transesterification of vinyl acetate with (9)-1a–g using P. cepacia (Amano PS) [A] lipase in n-hexane at 4 and
22°Ca
Entry
Substrate
(9)-1
Ar
Temp. (°C)
Enzyme
Time (h)
Conv. (%)b
Alcohol
(R)-(−)-1 e.e.s
(%)c
Ester (S)-(+)-2 Eb
e.e.p (%)c
1
a
C6H5-
22
4
22
22
4
22
4
22
4
22
22
4
22
4
22
22
4
A
A
B
A
A
A
A
A
A
B
A
A
A
A
B
A
A
17
65
22
48
98
24
79
21
74
28
52
103
21
80
24
54
128
49
49
41
50
53
50
52
51
51
55
53
46
51
44
55
47
40
87
90
64
89
98
90
99
93
96
98
95
80
90
74
96
78
64
90
93
92
88
87
91
91
88
91
80
83
93
85
93
78
89
95
57
94
47
46
65
66
111
53
84
41
39
68
38
62
31
41
76
2
3
4
b
c
d
2-CH3-C6H4-
3-CH3-C6H4-
4-CH3-C6H4-
5
6
e
f
2-CH3O-C6H4-
4-Cl-C6H4-
7
g
2,6-Cl-C6H3-
a Conditions: ( )-1a (1 mmol), vinyl acetate (3 mmol, 258 mg), lipase from P. cepacia (Amano PS) [A] or P. fluorescens (Amano AK) [B] (180 mg)
and n-hexane (10 mL) at 22 or 4°C.
b See Table 1.
c See Table 1.
4. Experimental
procedures (e.g. 10 mmol of ( )-1a–g, 15 mmol of
acetyl chloride, 15 mmol of pyridine in CH2Cl2 (30 mL)
at 22°C).
4.1. General
Lipases from P. cepacia (Amano PS, Amano PS immo-
bilized on diatomite) and P. fluorescens (Amano AK)
were purchased from Amano Pharmaceutical Co., Ltd
(Nagoya, Japan). Novozym® SP 435 (immobilized C.
antarctica-B lipase) was kindly gifted by Novo Nordisk
4.2. Analytical methods
Microanalyses were performed by the Laboratoire Cen-
tral de Microanalyse du CNRS, Gif sur Yvette, France.
1H (250 or 400 MHz) and 13C (50, 62.9 or 100.6 MHz)
NMR spectra were recorded on Bruker AC-200, 250 or
400 spectrometer in CDCl3 with TMS as the internal
standard. Chemical shifts (l) are given in ppm. Optical
rotation measurements were recorded on a DiP-370
JASCO polarimeter. HPLC analyses were run on a
Thermo-Separation Products P-100 instrument. Optical
purities of unreacted nitrooxy alcohols (R)-1a–g and
their acetates (S)-2a–g were controlled by HPLC analy-
sis on a chiral column Pharmachir 4C (1/4×250 mm)
and directly determined using racemic compounds as
references. The conditions were: n-hexane: iso-
propanol=90:10 v/v, 70 bar, 254 nm, 22°C for 1a–c, 1e
and 2a–c, 2e; n-hexane: iso-propanol=95:5 v/v, 80 bar,
254 nm, 22°C for 1d, 1f, 1g, and 2d, 2f and 2g. The
retention times (tR/min) were as follows: 1a: 13.06 (S),
20.93 (R); 2a: 10.59 (S), 11.43 (R); 1b: 15.03 (S), 26.09
(R); 2b: 10.49 (S), 12.64 (R); 1c: 14.28 (S), 19.99 (R);
2c: 10.66 (S), 12.28 (R); 1d: 16.01 (S), 21.93 (R); 2d:
8.24 (S), 9.26 (R); 1e: 11.55 (S), 12.93 (R); 2e: 13.93
(S), 28.79 (R); 1f: 17.09 (S), 17.97 (R); 2f: 10.96 (S),
11.42 (R); 1g: 12.78 (S), 14.09 (R); 2g: 6.09 (S), 7.24
(R). Column chromatography was performed on Merck
silica gel 60 (230–400 mesh). TLC was carried out using
glass sheets pre-coated with silica gel 60 F254 prepared
by Merck.
(Bagsvaerd, Denmark). Chirazyme® Lipases
&
Esterases, Screening Set Industrial Enzymes 2 (Chi-
razyme® L-1, lyo. and Chirazyme® L-1, c.-f., lyo. (B.
cepacia, formerly P. cepacia); immobilized Chirazyme®
L-2, c.-f., lyo., Chirazyme® L-2, c.-f., C2, lyo. and
Chirazyme® L-2, c.-f., C3, lyo. (C. antarctica, fraction
B); Chirazyme® L-3, lyo. and Chirazyme® L-3, purified,
lyo. (Candida rugosa, formerly Candida cylindracea);
Chirazyme® L-5, lyo. (C. antarctica, fraction A); Chi-
razyme® L-6, lyo. (Pseudomonas species); Chirazyme®
L-7, lyo. (porcine pancreas lipase); Chirazyme® L-8,
lyo. (Thermomyces species, formerly Humicola species);
Chirazyme® L-10, lyo. (Alcaligines species) and Chi-
razyme® L-12, lyo. (lipase from thermophilic microor-
ganism)) was kindly gifted by Roche Molecular
Biochemicals (Mannheim, Germany).
All the commercially available chemicals were obtained
from Aldrich and Fluka. Solvents of analytical-grade
quality were purchased from Lab Scan Ltd and
Aldrich. The racemic nitrooxy alcohols 1a–g were pre-
pared by previously described methods.3,36,37 The
racemic acetates as well as the other esters were synthe-
sized from the corresponding alcohols and acetyl chlo-
ride or acetic anhydride according to the usual

B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
2117
51.76; H, 5.09; N, 5.49. Found: C, 51.82; H, 5.07; N,
5.33%.
4.3. Typical acetylation procedure for racemic nitrooxy
alcohols ( )-1a–g using P. cepacia (Amano PS) [A] or
P. fluorescens (Amano AK) [B] lipase in n-hexane at 4
or 22°C
1
(S)-2b: H NMR (400 MHz, CDCl3, ppm): l 2.13 (s,
3H, COCH3), 2.23 (s, 3H, aromatic CH3), 4.15 (d,
J=5.2 Hz, 2H, CH2ONO2), 4.71–4.93 (m, 2H,
OCH2), 5.44–5.55 (m, 1H, chiral CH), 6.78–6.83 (m,
1H, aromatic CH), 6.89–6.95 (m, 1H, aromatic CH),
7.14–7.21 (m, 2H, aromatic CH); 13C NMR (100.6
Vinyl acetate (3 mmol, 258 mg) and P. cepacia (Amano
PS) [A] or P. fluorescens (Amano AK) [B] lipase (180
mg) were added to a solution of the racemic nitrooxy
alcohol 1a–g (1 mmol) in 10 mL of n-hexane. The
mixture was stirred at 4 or 22°C and monitored by
TLC. After the appropriate time (Table 7), the reaction
was stopped by filtering off the solid enzyme and the
solvent was evaporated under reduced pressure. The
crude mixture of acetate (S)-(+)-2a–g and unreacted
alcohol (R)-(−)-1a–g was separated by flash chromatog-
raphy on silica gel with hexane–ethyl acetate (15:1 v/v)
as the eluent. For all of unreacted alcohols (R)-1a–g
and their acetates (S)-2a–g determination of optical
purity was performed by means of chiral HPLC column
chromatography (Pharmachir 4C (1/4×250 mm)). Opti-
cal rotation values in all cases were in accordance with
the literature data.3 1H NMR spectra of enantiomeric
nitrooxy alcohols 1a–g were identical with those of the
racemic compounds ( )-1a–g as described in the
literature3 and their 13C NMR data are as follows:
(R)-1a: 13C NMR (62.9 MHz, CDCl3, ppm): l 67.03
(CH), 68.07 (CH2O), 73.09 (CH2ONO2), 114.42,
121.65, 129.61, 157.87 (C-Ar).
MHz, CDCl3, ppm):
l 16.04 (CH3-Ar), 20.75
(COCH3), 65.53 (CH2O), 68.29 (CH), 70.62
(CH2ONO2), 110.88, 121.30, 126.78, 126.87, 130.88,
155.93 (C-Ar), 170.05 (CꢀO); IR (neat, cm−1): 1630,
1245 (NO2), 1710 (CꢀO). Anal. calcd for C12H15NO6
(269): C, 53.53; H, 5.57; N, 5.20. Found: C, 53.48; H,
5.62; N, 5.17%.
1
(S)-2c: H NMR (400 MHz, CDCl3, ppm): l 2.13 (s,
3H, COCH3), 2.30 (s, 3H, aromatic CH3), 4.16 (d,
J=5.18 Hz, 2H, CH2ONO2), 4.70–4.93 (m, 2H,
OCH2), 5.40–5.49 (m, 1H, chiral CH), 6.68–6.73 (m,
2H, aromatic CH), 6.75–6.85 (m, 1H, aromatic CH),
7.15–7.24 (m, 1H, aromatic CH); 13C NMR (100.6
MHz, CDCl3, ppm): l 21.45 (CH3–Ar), 20.74
(COCH3), 65.50 (CH2O), 68.18 (CH), 70.46
(CH2ONO2), 111.32, 115.18, 122.54, 129.45, 139.89,
157.86 (C-Ar), 170.09 (CꢀO); IR (neat, cm−1): 1630,
1230 (NO2), 1720 (CꢀO). Anal. calcd for C12H15NO6
(269): C, 53.53; H, 5.57; N, 5.20. Found: C, 53.59; H,
5.42; N, 5.11%.
1
(S)-2d: H NMR (400 MHz, CDCl3, ppm): l 2.12 (s,
(R)-1b: 13C NMR (62.9 MHz, CDCl3, ppm): l 16.05
(CH3-Ar), 67.07 (CH), 68.06 (CH2O), 73.35
(CH2ONO2), 110.98, 121.25, 126.60, 126.88, 130.84,
155.81 (C-Ar).
3H, COCH3), 2.30 (s, 3H, aromatic CH3), 4.12 (d,
J=5.2 Hz, 2H, CH2ONO2), 4.68–4.91 (m, 2H,
OCH2), 5.39–5.43 (m, 1H, chiral CH), 6.78–6.84 (m,
2H, aromatic CH), 7.08–7.13 (m, 2H, aromatic CH);
13C NMR (100.6 MHz, CDCl3, ppm): l 20.40 (CH3-
Ar), 20.76 (COCH3), 65.64 (CH2O), 68.24 (CH),
70.58 (CH2ONO2), 114.32, 129.99, 130.93, 155.79
(C-Ar), 170.07 (CꢀO); IR (neat, cm−1): 1630, 1240
(NO2), 1710 (CꢀO). Anal. calcd for C12H15NO6 (269):
C, 53.53; H, 5.57; N, 5.20. Found: C, 53.46; H, 5.39;
N, 5.26%.
(R)-1c: 13C NMR (62.9 MHz, CDCl3, ppm): l 21.42
(CH3-Ar), 66.98 (CH), 68.03 (CH2O), 73.17
(CH2ONO2), 111.26, 115.24, 122.42, 129.31, 139.74,
157.89 (C-Ar).
(R)-1d: 13C NMR (62.9 MHz, CDCl3, ppm): l 20.42
(CH3-Ar), 67.02 (CH), 68.29 (CH2O), 73.19
(CH2ONO2), 114.29, 130.02, 130.95, 155.80 (C-Ar).
(R)-1e: 13C NMR (62.9 MHz, CDCl3, ppm): l 55.63
(CH3O-Ar), 66.76 (CH), 70.47 (CH2O), 73.06
(CH2ONO2), 111.87, 115.03, 121.01, 122.45, 147.39,
149.44 (C-Ar).
1
(S)-2e: H NMR (400 MHz, CDCl3, ppm): l 2.10 (s,
3H, COCH3), 3.84 (s, 3H, aromatic CH3O), 4.18 (d,
J=5.6 Hz, 2H, CH2ONO2), 4.71–4.93 (m, 2H,
OCH2), 5.38–5.48 (m, 1H, chiral CH), 6.78–7.04 (m,
4H, aromatic CH); 13C NMR (100.6 MHz, CDCl3,
ppm): l 20.79 (COCH3), 55.76 (CH3O-Ar), 67.51
(CH2O), 68.44 (CH), 70.67 (CH2ONO2), 112.24,
115.70, 120.87, 122.88, 147.49, 150.10 (C-Ar), 170.10
(CꢀO); IR (neat, cm−1): 1630, 1235 (NO2), 1718
(CꢀO). Anal. calcd for C12H15NO7 (285): C, 50.52; H,
5.26; N, 4.91. Found: C, 50.48; H, 5.18; N, 4.79%.
(R)-1f: 13C NMR (50 MHz, CDCl3, ppm): l 66.92
(CH), 68.52 (CH2O), 73.03 (CH2ONO2), 115.73,
126.51, 129.46, 156.53 (C-Ar).
(R)-1g: 13C NMR (50 MHz, CDCl3, ppm): l 67.35
(CH), 72.87 (CH2O), 73.08 (CH2ONO2), 125.70,
129.04, 150.19 (C-Ar).
1
(S)-2f: H NMR (250 MHz, CDCl3, ppm): l 2.12 (s,
1H and 13C NMR spectra, IR data as well as micro-
3H, COCH3), 4.11 (d, J=5.08 Hz, 2H, CH2ONO2),
4.61–4.95 (m, 2H, OCH2), 5.39–5.49 (m, 1H, chiral
CH), 6.75–6.92 (m, 2H, aromatic CH), 7.21–7.32 (m,
2H, aromatic CH); 13C NMR (50 MHz, CDCl3,
ppm): l 20.71 (COCH3), 65.79 (CH2O), 68.01 (CH),
70.34 (CH2ONO2), 115.75, 126.54, 129.44, 156.46
(C-Ar), 170.00 (CꢀO); IR (neat, cm−1): 1630, 1255
(NO2), 1710 (CꢀO). Anal. calcd for C11H12ClNO6
(289.45): C, 45.60; H, 4.14; N, 4.83. Found: C, 45.51;
H, 4.18; N, 4.72%.
analyses of acetates 2a–g are as follows:
1
(S)-2a: H NMR (400 MHz, CDCl3, ppm): l 2.12 (s,
3H, COCH3), 4.15 (d, J=5.2 Hz, 2H, CH2ONO2),
4.69–4.91 (m, 2H, OCH2), 5.39–5.50 (m, 1H, chiral
CH), 6.88–6.95 (m, 2H, aromatic CH), 6.98–7.03 (m,
1H, aromatic CH), 7.27–7.34 (m, 2H, aromatic CH);
13C NMR (100.6 MHz, CDCl3, ppm): l 20.80
(COCH3), 65.44 (CH2O), 68.23 (CH), 70.53
(CH2ONO2), 114.47, 121.65, 129.61, 157.87 (C-Ar),
170.10 (CꢀO); IR (neat, cm−1): 1630, 1240 (NO2),
1710 (CꢀO). Anal. calcd for C11H13NO6 (255): C,
1
(S)-2g: H NMR (250 MHz, CDCl3, ppm): l 2.14 (s,
3H, COCH3), 4.10–4.30 (m, 2H, CH2ONO2), 4.71–

2118
B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
5.09 (m, 2H, OCH2), 5.39–5.50 (m, 1H, chiral CH),
6.98–7.09 (m, 1H, aromatic CH), 7.25–7.35 (m, 2H,
aromatic CH); 13C NMR (62.9 MHz, CDCl3, ppm): l
20.77 (COCH3), 68.48 (CH), 70.06 (CH2O), 70.51
(CH2ONO2), 125.76, 129.05, 150.20 (C-Ar), 170.09
(CꢀO); IR (neat, cm−1): 1630, 1245 (NO2), 1715 (CꢀO).
Anal. calcd for C11H11Cl2NO6 (323.9): C, 40.75; H,
3.39; N, 4.32. Found: C, 40.65; H, 3.28; N, 4.19%.
C.-L.; Phillipov, G.; Stubberfield, J.; Horowitz, J.-D.
Circulation 2000, 102, 2810.
7. (a) Brunner, D.; Weisbord, J.; Meshulam, N.; Margulis,
S. Mu¨nch. Med. Wschr. 1980, 122, 801; (b) Saito, M.;
Nobuyoshi, M.; Nakamura, N.; Nishiyama, S.; Haze, K.;
Hiramori, K.; Ikeda, M. Arzneim.-Forsch./Drug Res.
1983, 33, 1301; (c) Wildfeuer, A.; Fries, W.; Laufen, H.;
Eibel, G. Therapiewoche 1984, 34, 7016; (d) Wildfeuer,
A.; Laufen, H.; Leitold, M. Arzneim.-Forsch./Drug Res.
1985, 35, 1289.
8. (a) Taira, N. Am. J. Cardiol. 1989, 63, 18j; (b) Markham,
A.; Plosker, G.-L.; Goa, K.-L. Drugs-Basel. 2000, 60,
955.
Acknowledgements
We are grateful to Roche Molecular Biochemicals
(Mannheim) for a kind gift of Chirazyme® Lipases &
Esterases, Screening Set Industrial Enzymes 2. We also
thank Amano Co. for a welcome supplying of P.
cepacia lipase (Amano PS and Amano PS immobilized
on diatomite) and Novo Nordisk for Novozym® SP
435.
9. Abrams, J. Am. Heart J. 1985, 110, 216.
10. (a) Gunnar, R. M.; Fisch, C. Circulation 1990, 82, 664;
(b) Parker, J. O. New Engl. J. Med. 1987, 316, 1635.
11. (a) Conti, C. R. Am. J. Cardiol. 1987, 60, 31H; (b) Mc
Gregor, M. Am. J. Cardiol. 1983, 74, 21.
12. Williams, D. O.; Amsterdam, E. A.; Mason, D. T. Circu-
lation 1975, 51, 421.
13. (a) Hayashi, Y.; Tomoike, H.; Nagasawa, K.; Yamada,
A.; Nishimjima, H.; Nakamura, M. Am. J. Physiol. 1988,
254, H1081; (b) Nabel, E. G.; Selwyn, A. P.; Ganz, P. J.
Am. Coll. Cardiol. 1990, 16, 349.
14. (a) Bennett, B. M.; Hayward, L. D.; Murad, F. J. Appl.
Cardiol. 1986, 1, 203; (b) Bennett, B. M.; Schro¨der, H.;
Hayward, L. D.; Waldman, S. A.; Murad, F. Circ. Res.
1988, 63, 693.
15. Zimmermann, T.; Leitold, M.; Laufen, H.; Riedel, K.-D.;
Stoss, P. Arzneim.-Forsch./Drug Res. 1994, 44, 474.
16. (a) Baba, S.; Shinohara, Y.; Sano, M.; Inoue, T.;
Masuda, S.; Kurono, M. J. Chromatogr. 1984, 305, 119;
(b) Hodgson, J. R.; Glennon, J. P.; Dacre, J. C.; Lee,
C.-C. Toxicol. Appl. Pharmacol. 1977, 40, 65; (c) Laufen,
H.; Scharpf, F.; Riedel, K.-D. Naunyn-Schmiedebergs
Arch. Pharmacol. (Suppl.) 1986, 332, 20.
References
1. Drug Stereochemistry; Wainer, I. W.; Drayer, D. E.,
Eds.; Marcel Dekker: New York, 1988.
2. (a) Ader, U.; Schneider, M. P. Tetrahedron: Asymmetry
1992, 3, 201; (b) Ader, U.; Schneider, M. P. Tetrahedron:
Asymmetry 1992, 3, 205; (c) Ader, U.; Schneider, M. P.
Tetrahedron: Asymmetry 1992, 3, 521; (d) Schneider, M.
P.; Goergens, U. Tetrahedron: Asymmetry 1992, 3, 525;
(e) Kamal, A.; Rao, A. B.; Rao, M. V. Tetrahedron Lett.
1992, 33, 4077; (f) Wunsche, K.; Schwaneberg, U.; Born-
scheuer, U. T.; Meyer, H. H. Tetrahedron: Asymmetry
1996, 7, 2917; (g) Bevinakatti, H. S.; Banerji, A. A. J.
Org. Chem. 1991, 56, 5372; (h) Kirchner, G.; Scollar, M.
P.; Klibanov, A. M. J. Am. Chem. Soc. 1985, 107, 7072;
(i) Chiou, T. W.; Chang, C.-C.; Lai, C.-T.; Tai, D.-F.
Bioorg. Med. Chem. Lett. 1997, 7, 433; (j) Theil, F.;
Lemke, K.; Ballschuh, S.; Kunath, A.; Schick, H. Tetra-
hedron: Asymmetry 1995, 6, 1323.
17. Merrow, R. T.; Cristol, S. J.; Van Dolah, R. W. J. Am.
Chem. Soc. 1953, 75, 4259.
18. Cainelli, G.; Manescalchi, F.; Martelli, G.; Panunzio, M.;
Plessi, L. Tetrahedron Lett. 1985, 26, 3369.
19. (a) Parida, S.; Dordick, J. S. J. Am. Chem. Soc. 1991,
113, 2253; (b) Masamune, S.; Choy, W. Aldrichimica Acta
1982, 3, 47; (c) Sariaslani, F. S.; Rosazza, J. P. N. Enzy.
Microb. Technol. 1984, 6, 242; (d) Scott, J. W. In Asym-
metric Synthesis; Morrison, J. D.; Scott, J. W., Eds.;
Academic Press: Orlando, FL, 1984; pp. 1–226; (e)
Mulzer, J. Nachr. Chem., Tech. Lab. 1984, 32, 798; (f)
Djadchenko, M. A.; Pivnitsky, K. K.; Theil, F.; Schick,
H. J. Chem. Soc., Perkin Trans. 1 1989, 2001.
20. (a) Nelson, W. L.; Wennerstrom, J. E.; Sankar, S. R. J.
Org. Chem. 1977, 42, 1006; (b) Bianchi, D.; Bosetti, A.;
Cesti, P.; Golini, P. Tetrahedron Lett. 1992, 33, 3231; (c)
Plattner, J. J.; Rapoport, H. J. Am. Chem. Soc. 1971, 93,
1758; (d) Goren, N.; Jakupovic, J.; Topal, S. Phytochem-
istry 1990, 29, 1467; (e) Theil, F.; Ballschuh, S.; Schick,
H.; Haupt, M.; Ha¨fner, B.; Schwarz, S. Synthesis 1988,
540; (f) Theil, F.; Ballschuh, S.; Kunath, A.; Schick, H.
Tetrahedron 1991, 47, 7569.
3. Pchelka, B. K.; Radomska, J.; Plenkiewicz, J. Synth.
Commun. 1998, 28, 4355.
4. Pchelka, B. K.; Loupy, A.; Plenkiewicz, J.; Blanco, L.
Tetrahedron: Asymmetry 2000, 11, 2719.
5. (a) Bassenge, E.; Zanziger, J. Am. J. Cardiol. 1991, 17,
304; (b) Bertolini, G.; Sala, A. Curr. Opin. Ther. Patents
1993, 3, 1499; (c) Ogawa, T.; Nakazato, A.; Sato, M.;
Hatayama, K. Synthesis 1990, 459; (d) Ogawa, T.;
Nakazato, A.; Tsuchida, K.; Hatayama, K. Chem.
Pharm. Bull. 1993, 41, 1049; (e) Ogawa, T.; Nakazato, A.;
Tsuchida, K.; Hatayama, K. Chem. Pharm. Bull. 1993,
41, 108; (f) Kobayashi, T.; Inoue, T.; Kita, Z.; Yoshiya,
H.; Nishino, S.; Oizumi, K.; Kimura, T. Chem. Pharm.
Bull. 1995, 43, 788; (g) Benedini, F.; Bertolini, G.;
Cereda, R.; Dona`, G.; Gromo, G.; Levi, S.; Mizrahi, J.;
Sala, A. J. Med. Chem. 1995, 38, 130; (h) Kawashima, Y.;
Ikemoto, T.; Horiguchi, A.; Hayashi, M.; Matsumoto,
K.; Kawarasaki, K.; Yamazaki, R.; Okuyama, S.;
Hatayama, K. J. Med. Chem. 1993, 36, 815.
21. (a) Yale, H. J.; Pribyl, E. J.; Braker, W.; Bergeim, F. H.;
Lott, W. A. J. Am. Chem. Soc. 1950, 72, 3710; (b) Yale,
H. J.; Pribyl, E. J.; Braker, W.; Bernstein, J.; Lott, W. A.
J. Am. Chem. Soc. 1950, 72, 3716; (c) Iriuchijima, S.;
Kojima, N. Agric. Biol. Chem. 1982, 46, 1153; (d) Terada,
T.; Yokoyama, T.; Furukubo, M.; Sakurai, M. Jpn.
6. (a) Hebert, D.; Lam, J.-Y.-T. J. Am. Coll. Cardiol. 2000,
36, 2311; (b) Santoro, A.; Rovati, L.-C.; Lanzini, R.;
Setnikar, I. Arzneim.-Forsch./Drug Res. 2000, 50, 897; (c)
Sage, P.-R.; De la Lande, I.-S.; Stafford, I.; Bennett,

B. K. Pchelka et al. / Tetrahedron: Asymmetry 12 (2001) 2109–2119
2119
Kokai Tokkyo Koho JP 0,116,598 [8,916,598] (Cl.
C12P41/ 00), 20 Jan., 1989.
32. Janssen, A. J. M.; Klunder, A. J. H.; Zwanenburg, B.
Tetrahedron 1991, 47, 7409.
22. (a) Thaker, K. A.; Patel, S. H. J. Sci. Ind. Res., India
1961, 20B, 327; (b) Nelson, W. L.; Wood, Jr., C. A. J.
Chem. Soc., Chem. Commun. 1973, 896; (c) Theil, F.;
Ballschuh, S.; Kunath, A.; Schick, H. Tetrahedron: Asym-
metry 1991, 2, 1031.
23. (a) Lopez Calahorra, F.; Geijo Calehoro, F. A.; Valles
Planna, J. M.; Prats, Palacin, J. Span. ES 544,545
(C07C043-23), 16 Mar., 1986; (b) Walsh, D. A.; Lo, Y.
S.; Shamblee, D. A.; Welstead, Jr., W. J.; Nolan, J. C.;
Graff, G. J. Med. Chem. 1990, 33, 2070.
33. (a) Theil, F.; Weidner, J.; Ballschuh, S.; Kunath, A.;
Schick, H. J. Org. Chem. 1994, 59, 388; (b) Theil, F.;
Weidner, J.; Ballschuh, S.; Kunath, A.; Schick, H. Tetra-
hedron Lett. 1993, 34, 305; (c) Guo, Z.-W.; Wu, S.-H.;
Chen, C.-S.; Girdauukas, G.; Sih, C. J. J. Am. Chem.
Soc. 1990, 112, 4942.
34. Egri, G.; Kolbert, A.; Balint, J.; Fogassy, E.; Novak, L.;
Poppe, L. Tetrahedron: Asymmetry 1998, 9, 271.
35. Mischitz, M.; Kroutil, W.; Wandel, U.; Faber, K. Tetra-
hedron: Asymmetry 1995, 6, 1261.
24. (a) Lohray, B. B.; Ahuja, J. R. J. Chem. Soc., Chem.
Commun. 1991, 95; (b) Lohray, B. B.; Gao, Y.; Sharpless,
K. B. Tetrahedron Lett. 1989, 30, 2623; (c) Gurjar, M. K.;
Sadalapure, K.; Adhikari, S.; Sarma, B. S.; Talukdar, A.;
Chorghade, M. S. Heterocycles 1998, 48, 1471; (d) Rama
Rao, A. V.; Gurjar, M. K.; Joshi, S. V. Tetrahedron:
Asymmetry 1990, 1, 697.
25. (a) Hayashi, T.; Tanaka, M.; Ogata, I. Tetrahedron Lett.
1977, 3, 295; (b) Tanaka, M.; Ogata, I. J. Chem. Soc.,
Chem. Commun. 1975, 735.
36. (a) Nichols, P. L.; Magnusson, A. B.; Ingham, J. D. J.
Am. Chem. Soc. 1953, 75, 4255; (b) Marans, N. S.;
Zielinski, R. P. J. Am. Chem. Soc. 1950, 72, 5330; (c)
Nichols, P. L.; Petty, W. L. J. Am. Chem. Soc. 1954, 76,
4385; (d) Nichols, P. L.; Ingham, J. D. J. Am. Chem. Soc.
1954, 76, 4387.
37. Iranpoor, N.; Salehi, P. Tetrahedron 1995, 51, 909.
38. Pchelka, B. K.; Plenkiewicz, J. J. Org. Prep. Proc. Int.
1998, 30, 87.
39. Faber, K. Biotransformations in Organic Chemistry, 3rd
26. Hayward, R. C.; Overton, C. H.; Whitman, G. H. J.
ed.; Springer: New York, 1997.
Chem. Soc., Perkin Trans. 1976, 2413.
40. (a) Chen, C. S.; Fujimoto, Y.; Girdaukas, G.; Sih, C. J. J.
Am. Chem. Soc. 1982, 104, 7294; (b) Guo, Z. W.; Sih, C.
J. J. Am. Chem. Soc. 1989, 111, 6836.
27. (a) Wang, Z.-M.; Zhang, X.-L.; Sharpless, K. B. Tetra-
hedron Lett. 1993, 34, 2267; (b) Hanessian, S.; Meffre, P.;
Girard, M.; Beaudoin, S.; Sanceau, J.-Y.; Bennani, Y. J.
Org. Chem. 1993, 58, 1991; (c) Sharpless, K. B.; Amberg,
W.; Bennani, Y. L.; Crispino, G. A.; Hartung, J.; Jeong,
K.-S.; Kwong, H.-L.; Morikawa, K.; Wang, Z.-M.; Xu,
D.; Zhang, X.-L. J. Org. Chem. 1992, 57, 2768; (d) Xu,
D.; Crispino, G. A.; Sharpless, K. B. J. Am. Chem. Soc.
1992, 114, 7570.
41. (a) Sakurai, T.; Margolin, A. L.; Russell, A. J.; Klibanov,
A. M. J. Am. Chem. Soc. 1988, 110, 7236; (b) Wang,
Y.-F.; Lalonde, J. J.; Momongan, M.; Bergbreiter, D. E.;
Wong, C. H. J. Am. Chem. Soc. 1988, 110, 7200; (c)
Nakamura, K.; Takebe, Y.; Kitayama, T.; Ohno, A.
Tetrahedron Lett. 1991, 32, 4941; (d) Secundo, F.; Riva,
S.; Carrea, G. Tetrahedron: Asymmetry 1992, 3, 267.
42. (a) Anthonsen, T.; Jongejan, J. A. Meth. Enzymol. 1997,
286, 473; (b) Anthonsen, T.; Hoff, B. H. Chem. Phys.
Lipids 1998, 93, 199; (c) Kvittingen, L. Tetrahedron 1994,
50, 8253; (d) Rubio, E.; Alfonso, F. M.; Klibanov, A. M.
J. Am. Chem. Soc. 1991, 113, 695.
28. (a) White, J. D.; Kang, M.-C.; Sheldon, B. G. Tetra-
hedron Lett. 1983, 24, 4539; (b) Hutchins, R. O.; Taffer,
I. M. J. Org. Chem. 1983, 48, 1360.
29. (a) Mikami, K.; Terada, M.; Nakai, T. J. Am. Chem. Soc.
1990, 112, 3949; (b) Corey, E. J.; Bakshi, R. K. Tetra-
hedron Lett. 1990, 31, 611; (c) Kikuchi, H.; Mori, K.
Agric. Biol. Chem. 1989, 53, 2095; (d) Brown, H. C.; Pai,
G. G.; Jadhav, P. K. J. Am. Chem. Soc. 1984, 106, 1531.
30. (a) Laumen, K.; Breitgoff, D.; Seemayer, R.; Schneider,
M. P. J. Chem. Soc., Chem. Commun. 1989, 148; (b)
Pederson, R. L.; Liu, K. K.-C.; Rutan, J. F.; Chen, L.;
Wong, C.-H. J. Org. Chem. 1990, 55, 4897; (c) Chen,
C.-S.; Liu, Y.-C.; Marsella, M. J. Chem. Soc., Perkin
Trans. 1 1990, 2559; (d) Goergens, U.; Schneider, M. P.
J. Chem. Soc., Chem. Commun. 1991, 1064; (e) Goergens,
U.; Schneider, M. P. J. Chem. Soc., Chem. Commun.
1991, 1066; (f) Kim, M.-J.; Choi, Y. K. J. Org. Chem.
1992, 57, 1605.
31. (a) Cesti, P.; Zaks, A.; Klibanov, A. M. Appl. Biochem.
Biotechnol. 1985, 11, 401; (b) Therisod, M.; Klibanov, A.
M. J. Am. Chem. Soc. 1986, 108, 5638; (c) Hennen, W. J.;
Sweers, H. M.; Wang, Y.-F.; Wong, C.-H. J. Org. Chem.
1988, 53, 4939; (d) Carrea, G.; Riva, S.; Secundo, F.;
Danieli, B. J. Chem. Soc., Perkin Trans. 1 1989, 1057; (e)
Adelhorst, K.; Bjo¨rkling, F.; Godtfredsen, S. E.; Kirk, O.
Synthesis 1990, 112; (f) Holla, E. W. Angew. Chem. 1989,
101, 222; (g) Cambou, B.; Klibanov, A. M. J. Am. Chem.
Soc. 1984, 106, 2687; (h) Ramaswamy, S.; Morgan, B.;
Oehlschlager, A. C. Tetrahedron Lett. 1990, 31, 3405.
43. Fitzpatrick, P. A.; Klibanov, A. M. J. Am. Chem. Soc.
1991, 113, 3166.
44. Ema, T.; Maeno, S.; Takaya, Y.; Sakai, T.; Utaka, M.
Tetrahedron: Asymmetry 1996, 7, 625.
45. Chen, C.-S.; Wu, S.-H.; Girdaukas, G.; Sih, C. J. J. Am.
Chem. Soc. 1987, 109, 2812.
46. (a) Theil, F.; Schick, H. Synthesis 1991, 533; (b) Suga-
hara, T.; Kuroyanagi, Y.; Ogasawara, K. Synthesis 1996,
1101; (c) Konno, H.; Ogasawara, K. Synthesis 1999,
1135; (d) Yoshida, N.; Konno, H.; Kamikubo, T.; Taka-
hashi, M.; Ogasawara, K. Tetrahedron: Asymmetry 1999,
10, 3849.
47. (a) Broos, J.; Sakodinskaya, I. K.; Engbersen, J. F. J.;
Verboom, W.; Reinhoudt, D. N. J. Chem. Soc., Chem.
Commun. 1995, 255; (b) Itoh, T.; Hiyama, Y.; Betchaku,
A.; Tsukube, H. Tetrahedron Lett. 1993, 34, 2617; (c)
Itoh, T.; Takagi, Y.; Murakami, T.; Hiyama, Y.;
Tsukube, H. J. Org. Chem. 1996, 61, 2158.
48. (a) Takagi, Y.; Teramoto, J.; Kihara, H.; Itoh, T.;
Tsukube, H. Tetrahedron Lett. 1996, 37, 4991; (b) Takagi,
Y.; Ino, R.; Kihara, H.; Itoh, T.; Tsukube, H. Chem.
Lett. 1997, 1247.
49. Sakai, T.; Kawabata, I.; Kishimoto, T.; Ema, T.; Utaka,
M. J. Org. Chem. 1997, 62, 4906.