8640
E. Pini et al. / Tetrahedron 64 (2008) 8638–8641
100
4.2.5. Compound 2e
Reaction time: 5 h. Recrystallisation from ethyl acetate; yellow
9
8
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
0
ꢁ
solid; yield 60%; mp dec >200 C;
max (KBr): 3422, 2962, 2924, 2852, 1654, 1636, 1004, 964 cm
l
MeOH: 333.7, 350.5, 369.7 nm;
ꢂ1
n
; d
H
(
200 MHz, CDCl
3
): 6.27–6.12 (10H, m, CH), 5.78–5.73 (2H, m,
CHCH
.6 Hz, CH
2
OH, CHCH
), 1.35 (1H, s, OH exch. with D
H18O requires 202.
3
), 4.03 (2H, d, J 7.3 Hz, CH
2
OH), 1.76 (3H, d, J
þ
6
C
3
2
O); MS: MH , found 203.
14
4.2.6. Compound 2f
Reaction time: 5 h. Recrystallisation from ethyl acetate; dark
ꢁ
yellow solid; yield 40%; mp dec >200 C;
lMeOH: 354.9, 373.3,
3
1
5
1
94.9 nm;
098, 1018, 800 cm
.86–5.75 (2H, m, CHCH
.76 (3H, d, J 6.1 Hz, CH
found 229. C16
n
max (KBr): 3430, 2962, 2924, 2852, 1684, 1654, 1268,
ꢂ1
;
d
H
(200 MHz, CDCl
OH, CHCH ), 4.02 (2H, d, J 5.2 Hz, CH
), 1.31 (s, 1H, OH exch. with D
20O requires 228.
3
): 6.32–6.17 (12H, m, CH),
0
12
24
36
Time (h)
48
60
72
2
3
2
OH),
O); MS: MH ,
þ
3
2
H
Figure 2. Time-course of the biotransformation of 2,4,6,8,10-dodecapentaenol 2d
catalysed by A. aceti MIM2000/28. -, alcohol; :, acid.
4.3. General procedure to obtain acids 3a–f
were obtained by direct infusion of a sample solution in a mixture
MeOH/H O/AcOH 10:89:1 under ionisation, ESI positive.
2
Triethyl phosphonoacetate (4.52 mmol, 0.89 mL) was added
under nitrogen to stirred suspension of sodium hydride
4.82 mmol, 192.85 mg of a 1:1 w/w dispersion in mineral oil) in
a
FTIR spectra were collected by using a Perkin–Elmer (MA, USA)
(
FT-IR Spectrometer ‘Spectrum One’ in a spectral region between
ꢁ
anhydrous THF (20 mL) at 0 C. By maintaining this temperature
the appropriate aldehyde (4.098 mmol) was added and the reaction
ꢂ1
4
000 and 450 cm . Samples were mixed in a mortar with KBr
(
1:100) and pressed in a hydraulic press (14 tons) to small tablets,
ꢁ
mixture was allowed to stand overnight at 4 C. The mixture was
which were then analysed by transmittance technique with 32
then poured into ice water and the reaction product was extracted
with diethyl ethers or precipitated in the reaction medium, filtered
and washed with water. The ethyl esters were suspended in 5% KOH
in methanol (50 mL) and refluxed for about 30 min. After cooling,
the precipitate was filtered and washed with cold methanol. A
solution of 5% aqueous HCl was added to the potassium salt until
acidic pH was reached. Acids 3a–f were filtered and washed with
a little amount of water.
ꢂ1
scansions and 4 cm resolutions.
All reagents, solvents and spectroscopic solvent grade employed
for HPLC and MS analyses and DMSO-d for NMR were purchased
6
from Aldrich Chemical.
4
.2. General procedure to obtain alcohols 2a–f
To a stirred solution of aldehyde 1a–f (2.2 mmol) in absolute
ethanol (20 mL), NaBH (3.3 mmol) in absolute ethanol (5 mL)
4.3.1. Compound 3a27
ꢁ
4
White solid; yield 23%; mp 125–126 C.
was added under nitrogen. The reaction mixture was stirred at
room temperature for 1–5 h (monitored by TLC). After distilled
water (30 mL) addition, the aqueous layer was extracted with
diethyl ether (3ꢀ30 mL) and the organic layers were dried under
sodium sulfate, filtered and then evaporated under reduced
pressure leading to a residue, which was purified by recrystalli-
4.3.2. Compound 3b27
ꢁ
Pale yellow solid; yield 23%; mp 188–189 C;
l
MeOH: 297 nm;
n
max (KBr): 3017, 2921, 1682, 1637, 1611, 1419, 1375, 1300, 1154, 1002,
ꢂ1
967, 922 cm
with D
14.97, 10.69 Hz, CH]CHCH]CHCOOH), 6.3–6.0 (2H, m, CH), 5.9
(1H, dq, J 6.72, 13.13 Hz, CHCH ), 5.8 (1H, d, J 15.27 Hz, ]CHCOOH),
.7 (3H, d, J 6.72 Hz, CH ); (53 MHz, DMSO): 168.3, 145.1, 141.4,
H
; d (200 MHz, DMSO): 12.1 (1H, s, CHCOOH exch.
2
O), 7.15 (1H, dd, J 15.27, 10.99, CH]CHCOOH), 6.7 (1H, dd, J
13
sation. Low solubility of compounds 2e and 2f did not allow
C
analysis.
3
1
3
d
C
.2.1. Compound 2a23
135.5, 132.0, 128.4, 121.6, 19.0; MS: MH , found 139. C
þ
4
8 10 2
H O re-
Reaction time: 1 h. Colourless oil; yield 90%.
quires 138.
4
.2.2. Compound 2b24
Reaction time: 1.5 h. Recrystallisation from petroleum ether
4.3.3. Compound 3c28
Yellow solid; yield 51%; mp 258–260 C;
(KBr): 3015, 2918, 2849, 1682, 1618, 1594, 1422, 1384, 1309, 1276,
ꢁ
l
MeOH: 329 nm;
n
max
ꢁ
gave a white solid; yield 90%; mp 99–100 C.
ꢂ1
1
008, 923 cm
with D
14.66, 10.69 Hz, CH]CHCH]CHCOOH), 6.3–6.0 (4H, m, CH), 5.9
(1H, dq, J 6.72, 13.13 Hz, CHCH ), 5.8 (1H, d, J 15.27 Hz, ]CHCOOH),
.8 (3H, d, J 6.72 Hz, CH ); (53 MHz, DMSO): 168.4, 144.6, 141.2,
137.8, 133.4, 132.4, 130.4, 130.1, 122.2, 19.0; MS: MH , found 165.
requires 164.
H
; d (200 MHz, DMSO): 12 (1H, s, CHCOOH exch.
4
.2.3. Compound 2c25
2
O), 7.2 (1H, dd, J 15.27, 11.3 Hz, CH]CHCOOH), 6.7 (1H, dd, J
Reaction time: 2 h. Recrystallisation from ethanol; white solid;
ꢁ
yield 70%; mp 99–100 C.
9
3
1
3
d
C
.2.4. Compound 2d26
þ
4
Reaction time: 3 h. Recrystallisation from ethyl acetate; pale
10 12 2
C H O
ꢁ
yellow solid; yield 80%; mp 203–204 C;
3
lMeOH: 310.5, 324.1,
40.5 nm;
n
max (KBr): 3280, 3186, 3014, 2920, 2870, 1684, 1654,
4.3.4. Compound 3d21
ꢂ1
ꢁ
1378, 1004, 964 cm
;
d
H
(200 MHz, CDCl
OH, CHCH ), 4.25 (2H, d, J 5.8 Hz, CH
), 1.31 (1H, s, CH OH exch. with D O);
): 133.5, 133.1, 133.9, 131.8–130.3, 18.3; MS: MH ,
16O requires 176.
3
): 6.27–6.12 (8H, m, CH),
Dark yellow solid; yield 20%; mp 260–262 C.
5
.85–5.74 (2H, m, CHCH
.82 (3H, d, J 6.6 Hz, CH
53 MHz, CDCl
found 177. C12
2
3
2
OH),
1
(
3
2
2
d
C
4.3.5. Compound 3e29
Dark orange solid; yield 10%; mp dec >200 C;
nmax (KBr): 3012, 2924, 2852, 1712, 1621, 1589, 1447, 1384, 1368,
þ
ꢁ
3
lMeOH: 379 nm;
H