Asymmetric microbial conversion of (E)-2-benzylideneindan-1-one by the filamentous fungi Botrytis cinerea, Trichoderma viride, and Eutypa lata

Article abstract of DOI:10.1016/j.tetasy.2011.09.010

The transformation of (E)-2-benzylideneindan-1-one 1 by the filamentous fungi Botrytis cinerea, Trichoderma viride, and Eutypa lata as biocatalysts was studied. The results showed the catalytic potential of these fungi in affording several hydroxylation a

Full text of DOI:10.1016/j.tetasy.2011.09.010

Tetrahedron: Asymmetry 22 (2011) 1653–1657
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Tetrahedron: Asymmetry
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Asymmetric microbial conversion of (E)-2-benzylideneindan-1-one by the
filamentous fungi Botrytis cinerea, Trichoderma viride, and Eutypa lata
⇑
⇑
Cristina Pinedo-Rivilla, Josefina Aleu , Isidro G. Collado
Departamento de Química Orgánica, Facultad de Ciencias, Universidad de Cádiz, Campus de Excelencia Internacional Agroalimentario, ceiA3, República Saharaui s/n,
Apdo. 40, 11510 Puerto Real, Cádiz, Spain
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 27 July 2011
Accepted 16 September 2011
Available online 18 October 2011
The transformation of (E)-2-benzylideneindan-1-one 1 by the filamentous fungi Botrytis cinerea, Tricho-
derma viride, and Eutypa lata as biocatalysts was studied. The results showed the catalytic potential of
these fungi in affording several hydroxylation and reduction products, three of them reported here for
the first time. The absolute configuration of enantiomerically pure 2-benzylindane derivatives was
determined.
Ó 2011 Elsevier Ltd. All rights reserved.
1. Introduction
ideneindan-1-one 1 by the filamentous fungi Botrytis cinerea, Trich-
oderma viride, and Eutypa lata.
Indanones and indenones are important classes of natural com-
pounds which are useful building blocks in the synthesis of various
carbocyclic and heterocyclic molecules of biological importance.
These structures can play an important role in medicinal chemistry
as they are present in various drugs or pharmaceutical com-
pounds.1 Specifically, (E)-2-benzylideneindan-1-one 1 has been
shown to exhibit cytotoxic activity against murine P388 and
L1210 leukaemic cells as well as human Molt 4/C8 and CEM T-
lymphocytes.2
2. Results and discussion
(E)-2-Benzylideneindan-1-one 1 was synthesized using the
methodology described in the literature.5 After purification, inde-
none 1 was added to cultures of whole cells of the filamentous fun-
gi B. cinerea, T. viride and E. lata to verify the bio-catalytic potential
of these fungi in the biotransformation of
ketones.
a, b-unsaturated
Several methods for their preparation have been reported, the
most classic involving as the first step the synthesis of indan-1-
one moiety followed by an aldol reaction with the appropriate
aldehydes.3 Problems may be encountered with chemical methods
such as incomplete transformation, moderate enantiomeric purity
and the use of toxic reagents. In contrast, biological methods are
useful in introducing chemical functions into inaccessible sites of
molecules and thereby producing rare structures with a high struc-
tural diversity. In most cases, biotransformations occur with high
regio- and stereo-specificities in Nature under mild and environ-
mentally friendly reaction conditions.4 In this context, the use of
microorganisms is advantageous owing to their rapid growth and
easy formation of multienzymatic systems.
The fungus B. cinerea produced just two compounds, (R)-2-(p-
hydroxybenzyl)-7-hydroxyindan-1-one 2 and (S)-2-(p-hydroxy-
benzyl)indan-1-one 3 (Scheme 1), the latter being reported here
for the first time.
Compound 2 was previously reported6 as a detoxification prod-
uct from the biotransformation of anti-( )-2-benzylindan-1-ol
anti-( )-5 by B. cinerea.
Comparison of the spectroscopic data of compounds 2 and 3
indicated that 3 possessed only a hydroxyl group, a fact corrobo-
rated by its HRMS, which was consistent with the molecular for-
mula C16H14O2. The appearance of a signal at 156.9 ppm in its
13C NMR spectrum (C-40) indicated a hydroxylation according to
product 2-(p-hydroxybenzyl)indan-1-one 3. Its absolute configura-
tion was determined by comparison of its specific rotation value
The biocatalysts used in this paper were filamentous fungi gi-
ven that are easily available from large-scale cultures. As part of
our research programme focusing on the biocatalytic potential of
fungi, we herein describe the biotransformation of (E)-2-benzyl-
(½a 2D0
ꢀ
¼ þ6, 36% ee) with that of (R)-2-benzylindan-1-one (R)-4
(½a 2D0
ꢀ
¼ ꢁ197:1, 70% ee), whose absolute configuration was
known.6 The compounds presented opposite values, indicating
the (S)-configuration at C-2. Compound (S)-2-(p-hydroxyben-
zyl)indan-1-one 3 is reported here for the first time.
⇑
Corresponding authors. Tel.: +34 956 016368; fax: +34 956 016193.
E-mail addresses: josefina.aleu@uca.es (J. Aleu), isidro.gonzalez@uca.es (I.G.
The saturated ketone 4 and alcohol 5 from the reduction of 1
(Scheme 2) were isolated from the broths of T. viride and E. lata.
Collado).
0957-4166/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetasy.2011.09.010

1654
C. Pinedo-Rivilla et al. / Tetrahedron: Asymmetry 22 (2011) 1653–1657
OH
O
O
O
7
2'
10
B. cinerea
2
+
4'
OH
OH
3
4
3
1
2
Scheme 1. Biotransformation products by Botrytis cinerea.
O
O
OH
+
1
4
5
Scheme 2. Reduction of (E)-2-benzylideneindan-1-one 1.
Spectroscopic data of these products were in agreement with those
found in the literature.5,7
O
O
OH
OH
Benzylindan-1-one 4 was obtained by both fungi with similar
yields while ee. T. viride afforded the (R)-enantiomer with 70% ee
in surface cultures. In shaken cultures, the (S)-enantiomer was
isolated with a yield of 15% and 13% ee. Moreover, the production
of 4 using E. lata was dependent on the production of other deriv-
atives and therefore yield and ee decreased dramatically over time
of fermentation. The absolute configurations of 4 were obtained by
HPLC analyses with a chiral stationary phase column and compar-
ison of their specific rotation values corresponded with those
found in the literature.6
OH
OH
10
11
O
2-Benzylindan-1-ol 5 was obtained in shaken cultures only.
Thus, T. viride gave the syn isomer (1R,2R)-2-benzylindan-1-ol
((1R,2R)-5) with 100% de and 99% ee after 5 days of fermentation.
Its absolute configuration was determined from oxidation of the
syn isomer (1R,2R)-5 and by HPLC analyses with a chiral stationary
phase column to give (R)-4 whose absolute configuration was
known.6 anti-(1S,2R)-2-Benzylindan-1-ol ((1S,2R)-5) was produced
by E. lata with 100% de and 95% ee.6
It is interesting to note that E. lata was also able to produce sev-
eral hydroxylated biotransformation compounds showing the high
biocatalytic potential of this fungus: syn-2-(hydroxyphenylmeth-
yl)indan-1-one 6, syn-2-benzyl-2,3-dihydroxyindan-1-one 7, anti-
2-benzyl-3-hydroxyindan-1-one 8, anti-2-benzylindan-1,2-diol 9,
3-hydroxy-2-(hydroxyphenylmethyl)indan-1-one 10, 2-hydroxy-
2-(hydroxyphenylmethyl)indan-1-one 11, and (E)-2-benzylidene-
3-hydroxyindan-1-one 12. These products were the result of
reductions and/or hydroxylations in the chain and in the five mem-
bered ring of (E)-2-benzylideneindan-1-one 1.
OH
12
It was significant that the shaken cultures were the best condi-
tion under which to biotransform (E)-2-benzylideneindan-1-one 1
using E. lata as the biocatalyst. syn-2-(Hydroxyphenylmethyl) in-
dan-1-one 6 and anti-2-benzyl-3-hydroxyindan-1-one 8 were pre-
viously reported as products from chemical reactions.1,8
Compound syn-2-benzyl-2,3-dihydroxyindan-1-one 7 was previ-
ously reported6 as a detoxification product from the biotransfor-
mation of anti-( )-2-benzylindan-1-ol anti-( )-5 by B. cinerea.
The alcohol 6 was obtained with 50% de in favour of the syn con-
figuration in an overall yield of 3% (relative stereochemistry being
assigned by correlation with 1H and 13C NMR data).8 The enantio-
meric purities of syn and anti alcohol 6 were determined by HPLC
analyses with a chiral stationary phase column to be 33% ee and
42% ee, respectively. This compound was isolated from the eight-
day broth only suggesting that 6 could be transformed into other
biotransformation products during the fermentation period.
anti-2-Benzyl-3-hydroxyindan-1-one 8,1 with 100% de, was the
major compound with the highest enantiomeric excess (46%) after
8 days of biotransformation. Compound anti-8 was also isolated
from the surface culture but the yield was insufficient to calculate
the enantiomeric excess.
O
O
OH
OH
H
OH
6
7
Compound syn-2-benzyl-2,3-dihydroxyindan-1-one 7 was only
isolated from the eight-day broth of the fungus E. lata with 100%
de. The relative stereochemistry was assigned by correlation with
1H and 13C NMR data and comparison of its specific rotation value
with that found in the literature.6
Compound 9 was isolated as a white solid with the molecular
formula C16H16O2 determined from its HRMS and corroborated
by 13C NMR data. The 1H NMR and 13C NMR spectra were close
O
OH
7
10
2
2'
4'
OH
3
4
OH
8
9

C. Pinedo-Rivilla et al. / Tetrahedron: Asymmetry 22 (2011) 1653–1657
1655
to that of 2-benzylindan-1-ol 5, but the absence of the signal cor-
responding to H-2 and the appearance of a signal at 83.7 ppm (C-2)
revealed the presence of a tertiary hydroxyl group at C-2 indicating
that 9 was a diol derivative. The relative stereochemistry of both
chiral carbons was determined by nOe experiments. Compound
anti-2-benzylindan-1,2-diol 9 was previously reported as a product
from chemical transformations9 but no spectroscopic data were
found for this compound in the literature. These data are reported
here for the first time.
and T. viride exhibited high stereoselectivity giving the anti isomer
(1S,2R)-2-benzylindan-1-ol (1S,2R)-5 with >99% de and 95% ee, and
the syn isomer (1R,2R)-2-benzylindan-1-ol (1R,2R)-5 with >99% de
and 99% ee, respectively.
E. lata was a very effective biocatalyst for (E)-2-benzylidenein-
dan-1-one 1 giving rise to several compounds, two of them re-
ported here for the first time. The high stereospecificity observed
for Eutypa and its ability to generate novel compounds indicates
that this fungus could be considered as a potential biocatalyst.
Two novel hydroxylated compounds, 10 and 11, were obtained
from the biotransformation of (E)-2-benzylideneindan-1-one 1 by
E. lata. Compound 10 was isolated as a yellow oil with an M+ peak
at m/z 254 and featuring 13C NMR spectrum consistent with the
molecular formula C16H1403. The 1H NMR spectrum was close to
that of 2-benzyl-3-hydroxyindan-1-one 8, but the appearance of
two signals at 70.7 and 74.4 ppm in the 13C NMR spectrum (C-3
and C-10, respectively) and two signals at 4.99 (H-3) and
5.03 ppm (H-10) in the 1H NMR spectrum showed that 10 pos-
sessed two secondary hydroxyl groups. Compound 3-hydroxy-2-
(hydroxylphenylmethyl)indan-1-one 10 was isolated as a single
diastereoisomer, with 100% de.
The biotransformation of (E)-2-benzylideneindan-1-one 1 by E.
lata also produced another compound, 11, whose 13C NMR spec-
trum was consistent with the molecular formula C16H14O3. The
1H NMR spectrum was close to that of 2-benzylindan-1-one 4,
but the presence of two signals at 68.6 and 5.45 ppm in the 13C
NMR and 1H NMR spectra, respectively, suggests that this com-
pound was hydroxylated at C-10. The absence of the signal corre-
sponding to H-2 showed the presence of a tertiary hydroxyl
group at C-2, indicating that 11 was a diol derivative. Compound
2-hydroxy-2-(hydroxyphenylmethyl)indan-1-one 11 was obtained
with 100% de.
Compounds 3-hydroxy-2-(hydroxylphenylmethyl)indan-1-one
10 and 2-hydroxy-2-(hydroxyphenylmethyl)indan-1-one 11 are
reported here for the first time.
(E)-2-Benzylidene-3-hydroxyindan-1-one 12, obtained only un-
der shaken conditions with 95% ee, was previously reported as a
product from chemical reactions and its spectroscopic data coin-
cided with those found in the literature.10 This is the only product
with a double bond at C-2/C-10 isolated from the E. lata broth,
whose structure could be explained by direct hydroxylation from
(E)-2-benzylideneindan-1-one 1 at C-3.
4. Experimental
4.1. General
Optical rotations were determined with a Perkin–Elmer 241
polarimeter. IR spectra were recorded on a Mattson Genesis spec-
trophotometer, series FTIR. 1H and 13C NMR measurements were
obtained on Varian Unity 400 and Varian Unity 600 NMR spec-
trometers with SiMe4 as the internal reference. Mass spectra were
recorded on a GC–MS Thermoquest spectrometer (model: Voy-
ager), and a VG Autospec-Q spectrometer. HPLC was performed
with a Hitachi/Merck L-6270 apparatus equipped with a UV–VIS
detector (L 6200) and a differential refractometer detector (RI-
71). TLC was performed on Merck Kiesegel 60 F254, 0.2 mm thick.
Silica gel (Merck) was used for column chromatography. Purifica-
tion by means of HPLC was performed with a silica gel column (Hi-
bar 60, 7 m, 1 cm wide, 25 cm long). Chemicals were supplied by
Fluka and Aldrich. All solvents used were freshly distilled. Enantio-
meric excesses were determined by means of HPLC analyses on a
chiral column (Chiralcel OD, Daicel, Japan): 254 nm.
4.2. Microorganism cultures
The culture of B. cinerea employed in this work, B. cinerea
UCA992, was obtained from grapes from the Domecq vineyard, Jer-
ez de la Frontera, Cádiz, Spain. This culture of B. cinerea is deposited
in the Universidad de Cadiz, Facultad de Ciencias, Mycological Her-
barium Collection (UCA). The E. lata and T. viride cultures used in
this research were obtained from the ‘Colección Española de Culti-
vos Tipo’ (CECT), Facultad de Biología, Universidad de Valencia,
Spain, where cultures of these strains are kept on deposit.
The stereoselectivity of these biotransformation compounds ob-
tained from E. lata was very high, giving only one diastereoisomer
but in the absence of at least one enantiomer of known configura-
tion, we had no way of determining which enantiomer was which.
4.3. General culture conditions
Fungi were grown at 25 °C on a Czapeck-Dox medium (B. cine-
rea UCA 992) or on a PDB medium (E. lata and T. viride) (150 mL per
bottle and 200 mL per flask). The shaken cultures were incubated
in an orbital shaker at 140 rpm. The substrate was dissolved in eth-
3. Conclusions
In summary, the studies described above have demonstrated
the biocatalytic potential of the filamentous fungi B. cinerea, T. vir-
ide, and E. lata to obtain biotransformation compounds with high
enantiomeric purity from (E)-2-benzylideneindan-1-one 1.
The main reaction paths involved reduction and hydroxylation
reactions at several positions. Thus, B. cinerea gave (R)-2-(p-
hydroxybenzyl)indan-1-one 26 and (S)-2-(p-hydroxybenzyl)-7-
hydroxyindan-1-one 3, reported here for the first time.
anol (200 lL) and then distributed in Roux bottles or flasks
(150 ppm per flask). Fermentation continued for a further period
of time after which the mycelium was filtered and then washed
with brine and ethyl acetate. The broth was extracted three times
with ethyl acetate and the extract dried over anhydrous sodium
sulfate. The solvent was then evaporated and the residue chro-
matographed, first on a silica gel column and then by HPLC with
an increasing gradient of ethyl acetate to petroleum ether.
(E)-2-Benzylideneindan-1-one 1 was reduced to its correspond-
ing saturated ketone 2-benzylindan-1-one 4 and saturated alcohol
2-benzylindan-1-ol 5 by E. lata and T. viride. Thus, T. viride afforded
compound 4 with a maximum yield of 15% after 10 days of fermen-
tation and 70% ee after 5 days from surface cultures. E. lata gave ke-
4.4. Biotransformation of (E)-2-benzylideneindan-1-one 1
4.4.1. Biotransformation by B. cinerea
(a) Surface culture. (E)-2-Benzylideneindan-1-one 1 was dis-
solved in ethanol and then distributed in 12 Roux bottles after
2 days growth. The fermentation was allowed to continue for 5
more days in six of the bottles and 10 more days in the other six.
Chromatography of the extract fermented for 5 days gave (E)-2-
tone
4 with a yield of 13% and 58% ee after 8 days of
biotransformation and from shaken cultures. The predominant
enantiomer was R, although the enantiomeric excess decreased
dramatically leading to an inversion of the configuration. E. lata

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C. Pinedo-Rivilla et al. / Tetrahedron: Asymmetry 22 (2011) 1653–1657
benzylideneindan-1-one 1 (9 mg), and (R)-2-(p-hydroxybenzyl)-7-
75:25, syn 33% ee, anti 42% ee), syn-2-benzyl-2,3-dihydroxyin-
hydroxyindan-1-one 2 (10 mg) (½a D20
ꢀ
¼ ꢁ3:8 (c 0.1, MeOH), 11%
dan-1-one 7 (1.7 mg) ((½a D20
¼ ꢁ17:0 (c 0.1, CHCl3), 26% ee, 100%
ꢀ
ee). Chromatography of the extract fermented for 10 days gave
de), anti-2-benzyl-3-hydroxyindan-1-one
8
(24 mg) ((½a 2D0
¼
ꢀ
(E)-2-benzylideneindan-1-one 1 (10 mg), and (R)-2-(p-hydroxy-
ꢁ38:0 (c 0.1, CHCl3), 100% de, 46% ee), anti-2-benzylindan-1,2-diol
benzyl)-7-hydroxyindan-1-one 2 (15 mg) ((½a D20
ꢀ
¼ ꢁ6:5 (c 0.1,
9 (15 mg) ((½a 2D0
¼ ꢁ15:0 (c 0.1, CHCl3), 100% de, 18% ee), 3-hydro-
ꢀ
MeOH), 19% ee). (b) Shaken culture. (E)-2-Benzylideneindan-1-one
1 was dissolved in ethanol and then distributed in 10 flasks
(500 mL) in an orbital shaker after 2 days growth. The fermenta-
tion was allowed to continue for 5 more days in five of the flasks
and 10 more days in the other five. Chromatography of the extract
fermented for 5 days gave (E)-2-benzylideneindan-1-one 1 (4 mg),
xy-2-(hydroxyphenylmethyl)indan-1-one 10 (8 mg) ((½a D20
¼
ꢀ
ꢁ50:6 (c 0.1, CHCl3), 100% de, 60% ee), and 2-hydroxy-2-(hydroxy-
phenylmethyl)indan-1-one 11 (2 mg) ((½a D20
ꢀ
¼ ꢁ28:0ꢂ (c 0.1,
CHCl3), 100% de, 98% ee). Chromatography of the extract fermented
for 15 days gave (E)-2-benzylideneindan-1-one 1 (9 mg), (S)-2-
benzylindan-1-one (S)-4 (10 mg) (½a D20
¼ þ23:5 (c 0.1, CHCl3),
ꢀ
and (R)-2-(p-hydroxybenzyl)-7-hydroxyindan-1-one
2
(17 mg)
10% ee), (1S,2R)-2-benzylindan-1-ol (1S,2R)-5 (5 mg) ((½a D20
¼
ꢀ
((½a 2D0
ꢀ
¼ ꢁ4:0 (c 0.1, MeOH), 12% ee). Chromatography of the ex-
ꢁ11:0 (c 0.1, CHCl3), 95% ee), (1R,2R)-2-benzylindan-1-ol (1R,2R)-
5 (traces), syn-2-(hydroxylphenylmethyl)indan-1-one 6 (traces),
tract fermented for 10 days gave (E)-2-benzylideneindan-1-one 1
(14 mg), and (S)-2-(p-hydroxybenzyl)indan-1-one
3
(50 mg)
anti-2-benzyl-3-hydroxyindan-1-one 8 (30 mg) ((½a D20
¼ ꢁ15:6 (c
ꢀ
((½a 2D0
ꢀ
¼ þ6:0 (c 0.1, MeOH), 36% ee).
0.1, CHCl3), 100% de, 19% ee), anti-2-benzylindan-1,2-diol 9
(8 mg) ((½a 2D0
¼ ꢁ7:07.0 (c 0.1, CHCl3), 100% de, 7% ee), 2-hydro-
ꢀ
4.4.2. Biotransformation by T. viride
xy-2-(hydroxyphenylmethyl)indan-1-one 11 (5 mg) ((½a D20
¼ ꢁ6:4
ꢀ
(a) Surface culture. (E)-2-Benzylideneindan-1-one 1 was dis-
solved in ethanol and then distributed in 12 Roux bottles after
2 days growth. The fermentation was allowed to continue for 5
more days in six of the bottles and 10 more days in the other six.
Chromatography of the extract fermented for 5 days gave (E)-2-
benzylideneindan-1-one 1 (16 mg), (R)-2-benzylindan-1-one (R)-
(c 0.1, CHCl3), 100% de, 22% ee), and (E)-2-benzylidene-3-hydrox-
yindan-1-one 12 (1.5 mg) ((½a D20
¼ þ62:5 (c 0.1, CHCl3), 95% ee).
ꢀ
4.5. Oxidation of (1R,2R)-2-benzylindan-1-ol (1R,2R)-5
The alcohol (1R,2R)-2-benzylindan-1-ol (1R,2R)-5 (5 mg,
0.022 mmol) was oxidised with manganese(IV) oxide (1.5 equiv)
in methylene chloride solution (1.5 mL) at room temperature. After
purification using a silica gel column, eluting with hexane/ethyl
acetate (9:1), the derivative (R)-(ꢁ)-2-benzylindan-1-one (R)-4
(98% yield) was afforded.
4 (2 mg) ((½a 2D0
¼ ꢁ197:1 (c 0.1, CHCl3), 86% ee), and syn-2-benzy-
ꢀ
lindan-1-ol 5 (traces). Chromatography of the extract fermented
for 10 days gave (E)-2-benzylideneindan-1-one 1 (2 mg), (R)-2-
benzylindan-1-one (R)-4 (3 mg) ((½a D20
¼ ꢁ162:0 (c 0.1, CHCl3),
ꢀ
70% ee), and syn-2-benzylindan-1-ol 5 (traces). (b) Shaken culture.
(E)-2-Benzylideneindan-1-one 1 was dissolved in ethanol and then
distributed in 10 flasks (500 mL) in an orbital shaker after 2 days
growth. The fermentation was allowed to continue for 5 more days
in five of the flasks and 10 more days in the other five. Chromatog-
raphy of the extract fermented for 5 days gave (E)-2-benzyliden-
eindan-1-one 1 (22 mg), (R)-2-benzylindan-1-one (R)-4 (3.5 mg)
4.5.1. (R)-2-(p-Hydroxybenzyl)-7-hydroxyindan-1-one 26
Obtained as a yellow oil, (½a D20
¼ ꢁ6:5 (c 0.1, MeOH), 19% ee.
ꢀ
HPLC (n-hexane/i-PrOH 97:3, 0.5 mL/min): tR 30.1 min (R) and
50.9 min (S).
((½a 2D0
ꢀ
¼ ꢁ179:0 (c 0.1, CHCl3), 78% ee), and (1R,2R)-2-benzylin-
4.5.2. (S)-2-(p-Hydroxybenzyl)indan-1-one 3
dan-1-ol (1R,2R)-5 (3 mg) (½a D25
ꢀ
¼ ꢁ5:0ꢂ (c 0.1, CHCl3), 100% de,
Obtained as a yellow oil, (½a D20
¼ þ6:0 (c 0.1, MeOH), 36% ee. IR
ꢀ
99% ee). Chromatography of the extract fermented for 10 days gave
mmax (film): 3344, 1688. 1H NMR (400 MHz, CD3OD): d 2.70 (ddd,
1H, J = 2.0, 9.7, 13.8 Hz, H-10), 2.82 (dt, 1H, J = 3.2, 16.9 Hz, H-3),
2.99 (m, 1H, H-2), 3.09 (dd, 1H, J = 7.3, 16.9 Hz, H-3), 3.19 (dd, 1H,
(E)-2-benzylideneindan-1-one 1 (3 mg), (S)-2-benzylindan-1-one
(S)-4 (20 mg) ((½a D20
¼ þ37:1 (c 0.1, CHCl3), 16% ee), (1R,2R)-2-ben-
ꢀ
zylindan-1-ol (1R,2R)-5 (8 mg) ((½a D20
ꢀ
¼ ꢁ4:0 (c 0.1, CHCl3), 79%
´
´
J = 4.4, 13.8 Hz, H-10), 6.66 (d, 2H, J = 8.5 Hz, H-3, H-5), 6.67 (m,
ee), and (1S,2R)-2-benzylindan-1-ol (1S,2R)-5 (2 mg) ((½a D20
ꢀ
¼
1H, H-4), 7.02 (m, 1H, H-5), 7.03 (d, 2H, J = 8.5 Hz, H-2, H-6), 7.08
(dt, 1H, J = 3.2, 8.2 Hz, H-6), 7.27 (dd, 1H, J = 3.5, 8.2 Hz, H-7). 13C
NMR (100 MHz, CD3OD): d 32.1 (t, C-3), 37.2 (t, C-10), 51.2 (d, C-2),
´
´
ꢁ7:2 (c 0.1, CHCl3), 64% ee).
´
´
108.9 (d, C-5), 116.2 (d, C-3, C-5), 121.2 (d, C-4), 125.1 (d, C-6),
4.4.3. Biotransformation by Eutypa lata
´
´
´
(a) Surface culture. (E)-2-Benzylideneindan-1-one 1 was dis-
solved in ethanol and then distributed in 12 Roux bottles after
7 days growth. The fermentation was allowed to continue for 8
more days in six of the bottles and 15 more days in the other six.
Chromatography of the extract fermented for 8 days gave (E)-2-
128.5 (d, C-7), 130.9 (d, C-2, C-6), 131.5 (s, C-1), 146.9 (s, C-9),
+
´
156.9 (s, C-4), 158.5 (s, C-8), 210.7 (s, C-1). MS (m/z, %): 238 (M ,
0.3), 148 (33), 107 (100), 77 (15). HRMS (EI, 70 eV): calcd for
C
16H14O2: 238.09938 [M]+; found: 238.0971. HPLC (n-hexane/i-
PrOH 97:3, 0.5 mL/min): tR 21.9 min (R) and 33.9 min (S).
benzylideneindan-1-one
(traces) and anti-2-benzylindan-1,2-diol
1
(36.3 mg), 2-benzylindan-1-one
4
¼
9
(1.2 mg) ((½a 2D0
ꢀ
4.5.3. 2-Benzylindan-1-one 4
ꢁ14:0 (c 0.1, CHCl3), 100% de, 16% ee). Chromatography of the ex-
tract fermented for 15 days gave (E)-2-benzylideneindan-1-one 1
Obtained as a colourless oil. Product structure assignments
were done attending to the spectroscopic data reported in the lit-
erature.5 HPLC (n-hexane/i-PrOH 9:1, 0.4 mL/min): tR 17.0 min (R)
and 18.4 min (S).
(34.3 mg), (R)-2-benzylindan-1-one (R)-4 (3 mg) ((½a D20
¼ ꢁ48:6
ꢀ
(c 0.1, CHCl3), 21% ee), and anti-2-benzylindan-1-ol 5 (traces). (b)
Shaken culture. (E)-2-Benzylideneindan-1-one 1 was dissolved in
ethanol and then distributed in 10 flasks (500 mL) in an orbital
shaker after 7 days growth. The fermentation was allowed to con-
tinue for 8 more days in five of the flasks and 15 more days in the
other five. Chromatography of the extract fermented for 8 days
gave (E)-2-benzylideneindan-1-one 1 (23 mg), (R)-2-benzylindan-
4.5.4. 2-Benzylindan-1-ol 5
Obtained as a white solid. Product structure assignments were
done attending to the spectroscopic data reported in literature.7
HPLC (n-hexane/i-PrOH 9:1, 0.4 mL/min): tR (anti): 14 min (S,R)
and 30 min (R,S); tR (syn): 18.7 min (R,R) and 23.1 min (S,S).
1-one (R)-4 (15 mg) ((½a D20
¼ ꢁ166:3 (c 0.1, CHCl3), 72% ee),
ꢀ
(1S,2R)-2-benzylindan-1-ol (1S,2R)-5 (1.8 mg) ((½a D20
ꢀ
¼ ꢁ11:0 (c
4.5.5. syn-2-(Hydroxyphenylmethyl)indan-1-one 6
0.1, CHCl3), 100% de, 95% ee), syn-2-(hydroxylphenylmeth-
Obtained as a colourless oil, (½a D20
¼ þ88:0 (c 0.1, CHCl3), syn/
ꢀ
yl)indan-1-one 6 (3 mg) ((½a D20
ꢀ
¼ þ88:0 (c 0.1, CHCl3), syn/anti
anti 75:25, syn 33% ee, anti 42% ee as determined by 1H NMR spec-

C. Pinedo-Rivilla et al. / Tetrahedron: Asymmetry 22 (2011) 1653–1657
1657
troscopy. HPLC (n-hexane/i-PrOH 9:1, 0.6 mL/min): tR (anti):
36.3 min (minor), 41.0 min (major); tR (syn): 45.9 min (minor),
58.2 min (major).
153.4 (s, Carom), 204.8 (s, C-1). MS (m/z, %): 254 (M+, 45), 236
(17), 147 (100); HRMS (EI, 70 eV): calcd for C16H14O3: 254.0943
[M]+; found: 254.0974. HPLC (n-hexane/i-PrOH 9.8:0.2, 1 mL/
min): tR 20.0 min (minor) and 32.4 min (major).
4.5.6. syn-2-Benzyl-2,3-dihydroxyindan-1-one 7
Obtained as a colourless oil, (½a D20
ꢀ
¼ ꢁ17:0 (c 0.1, CHCl3), 26% ee,
4.5.10. 2-Hydroxy-2-(hydroxylphenylmethyl)indan-1-one 11
100% de as determined by 1H NMR spectroscopy. HPLC syn-isomer
(n-hexane/i-PrOH 95:5, 0.8 mL/min): tR 16.8 min (major) and
23.8 min (minor).
Obtained as a colourless oil, (½a D20
¼ ꢁ28:0 (c 0.1, CHCl3), 100%
ꢀ
de, 98% ee. IR mmax (film): 3417, 2925, 1631. 1H NMR (400 MHz,
CDCl3): d 2.63 (dd, 1H, J = 3.0 Hz, 18.8 Hz, H-3), 3.13 (dd, 1H,
J = 6.7 Hz, 18.8 Hz, H-30), 5.45 (dd, 1H, J = 3.0 Hz, 6.7 Hz, H-10),
7.49 (m, 4H, Harom), 7.70 (m, 4H, Harom), 7.75 (d, 1H, J = 7.6 Hz,
H-7). 13C NMR (100 MHz, CDCl3): d 47.2 (t, C-3), 68.6 (d, C-10),
123.3 (d, C-7), 125.8 (d, Carom), 126.8 (d, Carom), 129.1 (d, Carom),
129.5 (d, C-30, C-50), 130.1 (d, Carom), 134.4 (s, Carom), 135.3 (d, C-
20, C-60), 136.4 (s, Carom), 154.9 (s, Carom), 202.0 (s, C-1). MS (m/
z,%): 254 (M+, 40), 236 (100), 218 (18), 91 (43); HRMS (EI, 70 eV):
calcd for C16H14O3: 254.0943; found: 254.1086 [M]+. HPLC (n-hex-
ane/i-PrOH 9.5:0.5, 0.8 mL/min): tR 19.2 min (major) and 25.7 min
(minor).
4.5.7. anti-2-Benzyl-3-hydroxyindan-1-one 8
Obtained as a colourless oil, (½a D20
¼ ꢁ38:0 (c 0.1, CHCl3), 46% ee,
ꢀ
100% de as determined by 1H NMR spectroscopy. HPLC anti-isomer
(n-hexane/i-PrOH 9:1, 0.6 mL/min): tR 13.7 min (major) and
14.4 min (minor).
4.5.8. anti-2-Benzylindan-1,2-diol 99
Obtained as a white solid. Mp 120–121 °C. (½a D20
¼ ꢁ15:0 (c 0.1,
ꢀ
CHCl3), 100 de, 93% ee. IR mmax (film): 3373, 2359. 1H NMR
(400 MHz, CDCl3): d 2.58 (d, 1H, J = 16.1 Hz, H-3), 2.79 (d, 1H,
J = 13.5 Hz, H-10), 3.10 (d, 1H, J = 16.1 Hz, H-30), 3.11 (d, 1H,
J = 13.5 Hz, H-100), 4.69 (d, 1H, J = 5.3 Hz, H-1), 7.14 (m, 4H, Har-
om), 7.24 (m, 4H, Harom), 7.30 (d, 1H, J = 7.0 Hz, Harom). 13C
NMR (100 MHz, CDCl3): d 40.0 (t, C-10), 42.8 (t, C-3), 81.9 (d, C-
1), 83.7 (s, C-2), 125.0 (d, Carom), 125.4 (d, Carom), 126.7 (d, Car-
om), 127.2 (d, Carom), 128.5 (d, C-30, C-50), 129.0 (d, Carom), 130.5
(d, C-20, C-60), 137.1 (s, C-10), 141.0 (s, C-9), 143.0 (s, C-8). MS (m/z,
%): 240 (M+, 18), 222 (30), 148 (100), 91 (90); HRMS (EI, 70 eV):
calcd for C16H16O2: 240.1150 [M]+; found: 240.1149. HPLC (n-hex-
ane/i-PrOH 9.5:0.5, 1 mL/min): tR 16.9 min (minor) and 18.6 min
(major).
4.5.11. (E)-2-Benzylidene-3-hydroxyindan-1-one 1210
Obtained as a white solid. Mp 186 °C. (½a D20
¼ þ62:5 (c 0.1,
ꢀ
CHCl3), 95% ee. HPLC (n-hexane/i-PrOH 9.8:0.2, 0.8 mL/min): tR
23.6 min (minor) and 25.4 min (major).
References
1. Petrignet, J.; Roisnel, T.; Greé, R. Chem. Eur. J. 2007, 13, 7374–7384.
2. Dimmock, J. R.; Kandepu, N. M.; Nazarali, A. J.; Kowalchuk, T. P.; Motaganahalli,
N.; Quail, J. W.; Mykytiuk, P. A.; Audette, G. F.; Prasad, L.; Perjesi, P.; Allen, T. M.;
Santos, Ch. L.; Szydlowski, J.; De Clercq, E.; Balzarini, J. J. Med. Chem. 1999, 42,
1358–1366.
3. Basavaiah, D.; Reddy, R. M. Tetrahedron Lett. 2001, 42, 3025–3027.
4. Alcalde, M.; Ferrer, M.; Plou, F. J.; Ballesteros, A. Trends Biotechnol. 2006, 24,
281.
5. Martínez, A.; Fernández, M.; Estévez, J.; Estévez, R.; Castedo, L. Tetrahedron
2005, 61, 485–492.
6. Pinedo-Rivilla, C.; Aleu, J.; Grande Benito, M.; Collado, I. G. Org. Biomol. Chem.
2010, 8, 3784–3789.
7. Aleu, J.; Fronza, G.; Fuganti, V. P.; Serra, S. Tetrahedron: Asymmetry 1998, 9,
1589–1596.
8. Orito, Y.; Hashimoto, S.; Ishizuka, T.; Nakajima, M. Tetrahedron 2006, 62, 390–
400.
9. Cromwell, N. H.; Martin, J. L. J. Org. Chem. 1968, 33, 1890–1894.
10. Yoshizawa, K.; Shioiri, T. Tetrahedron 2007, 63, 6259–6286.
4.5.9. 3-Hydroxy-2-(hydroxylphenylmethyl)indan-1-one 10
Obtained as a yellow oil, (½a D20
¼ ꢁ50:6 (c 0.1, CHCl3), 100% de,
ꢀ
60% ee. IR mmax (film): 3388, 2927, 1693, 1051.1H NMR (400 MHz,
CDCl3): d 2.99 (dd, 1H, J = 4.1, 9.4 Hz, H-2), 4.99 (d, 1H, J = 4.1 Hz,
H-3), 5.03 (d, 1H, J = 9.4 Hz, H-10), 7.47 (m, 6H, Harom), 7.61 (d,
1H, J = 7.6 Hz, Harom), 7.68 (t, 1H, J = 7.3 Hz, Harom), 7.77 (d, 1H,
J = 7.6 Hz, Harom). 13C NMR (100 MHz, CDCl3): d 64.3 (d, C-2),
70.7 (d, C-3), 74.4 (d, C-10), 123.4 (d, Carom), 125.6 (d, Carom),
126.8 (d, C-20, C-60), 128.7 (d, Carom), 129.0 (d, C-30, C-50), 129.5
(d, Carom), 135.2 (s, Carom), 135.9 (d, Carom), 140.8 (s, C-10),