Enantioselective microbial oxidation of allyl alcohols

Article abstract of DOI:10.1246/cl.2007.1428

A new route to the optically active allyl alcohols by microbial oxidation is disclosed. Yamadazyma farinosa IFO 10896, a yeast, efficiently catalyzes the enantioselective oxidation of allyl alcohols to afford the corresponding optically active alcohols as the remaining substrates. This reaction is applicable to both cyclic and acyclic compounds. Copyright

Full text of DOI:10.1246/cl.2007.1428

1428
Chemistry Letters Vol.36, No.12 (2007)
Enantioselective Microbial Oxidation of Allyl Alcohols
Kazutsugu Matsumoto,ꢀ1 Yoichi Kawabata,2 Satoshi Okada,2 Jun Takahashi,2 Key Hashimoto,1
Yuto Nagai,1 Junichi Tatsuta,1 and Minoru Hatanaka2
1Department of Chemistry, Meisei University, 2-1-1 Hodokubo, Hino, Tokyo 191-8506
2Department of Applied Chemistry and Biotechnology, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507
(Received September 11, 2007; CL-070995; E-mail: mkazu@chem.meisei-u.ac.jp)
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80
60
40
20
0
A new route to the optically active allyl alcohols by micro-
bial oxidation is disclosed. Yamadazyma farinosa IFO 10896,
a yeast, efficiently catalyzes the enantioselective oxidation of
allyl alcohols to afford the corresponding optically active
alcohols as the remaining substrates. This reaction is applicable
to both cyclic and acyclic compounds.
O
Me
Me
3
OH
The enzyme-catalyzed oxidation of alcohols is one of the
useful tools for obtaining the corresponding ketones and carbox-
ylic acids. Although numerous examples have been reported for
the enzymatic reduction of the carbonyl group, little attention
has been paid to this oxidation.1 In particular, there are only a
few reports regarding the oxidation of allyl alcohols.2,3 Howev-
er, biocatalytic oxidation could be an environmentally benign
procedure as a substitute for traditional chemical reactions.
Furthermore, the kinetic resolution by the enzymatic enantiose-
lective oxidation of secondary alcohols could produce optically
active alcohols with high ee’s as the remaining substrates.
In previous studies, Yamadazyma farinosa IFO 10896, a
yeast, could transform various types of acyclic and cyclic com-
pounds into the corresponding optically active products. For ex-
ample, the yeast enantiomerically reduced acyclic4 and cyclic5
ketones to give the alcohols. The asymmetric reduction of the
C=C double bond of ꢀ,ꢁ-unsaturated ketones occurred using
the same yeast to afford the corresponding saturated ketones,
and besides, the oxidation of cyclic alcohols was also observed.5
These results indicate that the yeast includes a plural oxido-
reductase, which encourages us to examine the yeast-mediated
oxidation. In this paper, we report the enantioselective oxidation
of allyl alcohols by the yeast that affords the corresponding
optically active alcohols.
We selected the readily available racemic 2-methyl-2-cyclo-
hexenol ((ꢁ)-1) as the representative substrate (Scheme 1). A
typical experimental procedure of the microbial reaction is as
follows. A sterilized nutrient medium of pH 7.2 (100 mL) was
inoculated with Y. farinosa and pre-incubated for 48 h at
30 ꢂC.6 The grown cells were collected by centrifugation
(3000 rpm for 10 min) to afford the resting wet cells (ca.
2.5 g). To a suspension of the cells in 0.1 M phosphate buffer
(40 mL, pH 6.5) was added the substrate (ꢁ)-1 (80 mL) and
2.4 g of glucose, and that was shaken at 30 ꢂC. The yields of
the products were determined by capillary GLC analysis after
4
0
5
10
15
20
25
Time/h
Figure 1. Transformation of allyl alcohol 1 as the substrate us-
ing the resting cells of Y. farinosa ( , allyl alcohol 1; , enone
2; , ketone 3; , alcohol 4).
extraction with Et2O.7 The time course of the % contents of
the products is shown in Figure 1. Interestingly, in this case,
the oxidation of the substrate 1 rapidly proceeded, and almost
half of the substrate 1 was consumed in only 0.5 h. On the other
hand, the corresponding unsaturated ketone, 2-methyl-2-cyclo-
hexenone (2), was simultaneously produced, although the yield
of 2 gradually decreased in accordance with the reduction of
the C=C double bond followed by the reduction of the carbonyl
group to afford 2-methylcyclohexanone (3) and 2-methylcyclo-
hexanol (4) in the same manner as in our previous study.5 We
then focused on the ee of the remaining substrate 1 because
the first oxidation step could occur with a high enantioselectiv-
ity. After purification by column chromatography on silica gel,
the ee was determined by 1H NMR analysis of the corresponding
(+)-ꢀ-methoxy-ꢀ-(trifluoromethyl)phenylacetic (MTPA) ester.
These results are shown in Table 1. As expected, the oxidation
proceeded with an excellent enantioselectivity, and, after a
21
0.5-h reaction, the optically active (R)-1 with 93% ee (½ꢀꢃD
¼
þ112ꢂ (c 0.95, MeOH)) was obtained in a 49% yield (E value =
60).8 The chemical reduction of C=C double bond of the obtain-
ing 1 with H2 and Pd/C followed by separation and MTPA es-
terification gave the corresponding cis-MTPA ester 5. The abso-
lute configuration of the original 1 was confirmed by comparing
the GLC spectrum of 5 with that of the authentic sample.5 After
the reaction for 24 h, the optically pure (R)-1 was afforded, al-
though the saturated alcohol 4 was also detected as an insepara-
ble impurity. The resulting enone 2 can be reduced by use of
chemical reagents, for example, NaBH4 with CeCl3, to repro-
duce the substrate (ꢁ)-1.
OH
OH
O
Me
Me
Me
Y. farinosa
+
We next examined the substrate specificity of the reaction
(Scheme 2). As a result, the reaction rate of the oxidation of
(ꢁ)-2-cyclohexenol (6) without a methyl group was extremely
fast. After a 2-h reaction, the racemic alcohol 6 was recovered
( )-1
(R)-1
2
Scheme 1.
Copyright ꢀ 2007 The Chemical Society of Japan

Chemistry Letters Vol.36, No.12 (2007)
1429
Table 1. Microbial oxidation of cyclic allyl alcohol (ꢁ)-1a
quickly reduced in the microbial system to give the saturated
ketone 14 in a 21% yield.
Allyl alcohol (R)-1
Yield/%b
Enone 2
Yield/%b
Time/h
E value
In conclusion, we have established the microbial enantiose-
lective oxidation of allyl alcohols as a new route to the optically
active allyl alcohols and the corresponding enones. In particular,
this reaction is applicable to the preparation of both cyclic and
acyclic optically active compounds. This procedure is expected
to be a useful tool for organic synthesis, and further investiga-
tions for applying this method and the study of the mechanism
are now in progress.
Ee/%
0.2
0.5
24
71
49
40
32
93
100
17
29
0
11
60
>35
aThe reaction was performed using 18 mM of the substrate.
bDetermined by GLC analysis with dodecane as the internal
standard.
OH
OH
O
References and Notes
1
a) Enzyme Catalysis in Organic Synthesis, ed. by K. Drauz,
H. Waldmann, VCH, Weinheim, 1994. b) A. S. Bommarius,
B. R. Riebel, Biocatalysis, Wiley-VCH, Weinheim, 2004.
c) K. Faber, Biotransformations in Organic Chemistry: A
Textbook, 5th ed., Springer Verlag, Berlin-Heidelberg-New
York, 2004. d) Modern Oxidation Methods, ed. by J.-E.
Y. farinosa
+
+
2 h
( )-6
6 (8%)
7 (84%)
OH
OH
O
Me
Me
Me
Y. farinosa
4 h
Backvall, Wiley-VCH, Weinheim, 2004.
¨
2
a) A. Hatanaka, O. Adachi, M. Ameyama, Agric. Biol. Chem.
1970, 34, 1574. b) E. G. DeMaster, T. Dahlseid, B. Redfern,
Chem. Res. Toxicol. 1994, 7, 414. c) S. Trivic, V. Leskovac,
Biochem. Mol. Biol. 1999, 47, 1.
C. Gorrebeeck, M. Spanoghe, D. Lanens, G. L. Lemiere,
R. A. Dommisse, J. A. Lepoivre, F. C. Alderweireldt, Recl.
Trav. Chim. Pays-Bas 1991, 110, 231.
a) T. Sugai, H. Ohta, Agric. Biol. Chem. 1990, 54, 1577. b)
N. Mochizuki, H. Yamada, T. Sugai, H. Ohta, Bioorg.
Med. Chem. 1993, 1, 71. c) Y. Ohtsuka, O. Katoh, T. Sugai,
H. Ohta, Bull. Chem. Soc. Jpn. 1997, 70, 483. d) T.
Yamazaki, A. Kuboki, H. Ohta, T. M. Mitzel, L. A. Paquette,
T. Sugai, Synth. Commun. 2000, 30, 3061. e) T. Tsujigami,
T. Sugai, H. Ohta, Tetrahedron: Asymmetry 2001, 12, 2543.
K. Matsumoto, Y. Kawabata, J. Takahashi, Y. Fujita, M.
Hatanaka, Chem. Lett. 1998, 283.
The medium contained 1.0% glucose, 0.7% polypeptone,
0.5% yeast extracts, and 0.5% K2HPO4 in distilled water.
Conditions for capillary GLC analysis: column, TC-WAX
(0.25 mm ꢅ 50 m, GL Sciences Inc.); injection, 130 ꢂC;
detector, 130 ꢂC; oven, 100 ꢂC; carrier gas, He; head pre-
suure, 2.4 kg/cm2; dodecane as the internal standard (6.7
min), 3 (10.1 min), cis-4 (13.5 min), trans-4 (13.9 min), 2
(15.9 min), 1 (22.5 min).
C. S. Chen, Y. Fujimoto, G. Girdaukas, C. J. Sih, J. Am.
Chem. Soc. 1982, 104, 7294. The E values were calculat-
ed by ln[(1 ꢄ conv.)(1 ꢄ ee(alcohol))]/ln[(1 ꢄ conv.)(1 +
ee(alcohol))] in all cases. The conversions were calculated
by 1 ꢄ yield(alcohol). In the cases of 1 (24-h reaction), 10
and 12, we considered that the ee’s of the alcohols were over
0.999.
H. Doucet, T. Ohkuma, K. Murata, T. Yokozawa, M.
Kozawa, E. Katayama, A. F. England, T. Ikariya, R. Noyori,
Angew. Chem., Int. Ed. 1998, 37, 1703.
Me Me
( )-8
E = 17
Me Me
Me Me
9 (42%)
O
(R)-8 (45%, 88% ee)
OH
OH
Y. farinosa
4 h
+
3
4
Me
( )-10
Me
Me
11 (42%)
(S)-10 (40%, 100% ee)
E = >35
Scheme 2.
OH
OH
O
Y. farinosa
+
72 h
OBn
OBn
OBn
OBn
( )-12
(R)-12 (35%, 100% ee)
13
E = >22
O
5
6
7
14 (21%)
Scheme 3.
in only 8% yield. On the other hand, (ꢁ)-2,4,4-trimethyl-2-
cyclohexenol (8) was enantioselectively oxidized to afford (R)-
25
8 (45%) with 88% ee and 9 (42%); (R)-8, ½ꢀꢃD ¼ þ65:7 (c
23
1.09, MeOH), lit.9 ½ꢀꢃD ¼ þ87:9 (c 1.00, MeOH) (94% ee
(R)) (E value = 17). Surprisingly, the oxidation of (ꢁ)-3-meth-
yl-2-cyclohexenol (10) proceeded with an excellent enantiose-
lectivity, although the enantioselective mode was different from
that in other cases, and the optically pure (S)-10 with the oppo-
site absolute configuration and the corresponding enone 11 were
8
9
22
obtained in 40% and 42%, respectively; (S)-10, ½ꢀꢃD ¼ ꢄ42:4
23
(c 0.37, CHCl3), lit.10 ½ꢀꢃD ¼ ꢄ26:7 (c 1.5, CHCl3) (29% ee
(S)) (E value = >35). These results indicated that the methyl
group at the C-2 position on the substrates is very important
for the S-selective oxidation, but the substrate bearing the C-3
methyl group could be captured into the enzyme active site with
a different angle and/or direction mode. It is noteworthy that
this reaction is applicable to not only cyclic compounds but
also an acyclic compound, (ꢁ)-5-benzyloxy-1-penten-3-ol (12)
(Scheme 3). The S-enantioselective oxidation of (ꢁ)-12 pro-
ceeded to afford the optically pure (R)-12 in a 35% yield (E
value = >22).11 In this case, the intermediate enone 13 was
10 Y. F. Wang, J. J. Lalonde, M. Momongan, D. E. Bergbreiter,
C. H. Wong, J. Am. Chem. Soc. 1988, 110, 7200.
11 The absolute configuration and the ee of 12 were determined
by the same methods as that in our previous paper. See:
M. Nogawa, M. Shimojo, K. Matsumoto, M. Okudomi, Y.
Nemoto, H. Ohta, Tetrahedron 2006, 62, 7300.
Published on the web (Advance View) November 3, 2007; doi:10.1246/cl.2007.1428