Supplementary Information
Synthesis of alcohols 1,2 and ketones 1,2
Alcohol 1 (1,2: 4,5-Di-O-isopropylidene-fructose):
The compound fructose (100 mmol, 18 g) was added into a 250 ml round-bottom
flask filled with 170 ml of dry acetone, then dropwise added slowly with 9 ml of
concentrated sulfuric acid at room temperature (or with 6.7 ml of perchloric acid at 0 °C)
while stirring. The resulting mixture was magnetically stirred at the given temperature for
18 h; subsequently，the pH of the solution was adjusted to 7-8 with appropriate amount of
ammonia water (NH3·H2O). After that, the solvent was evaporated off by a rotary
evaporator at 30 °C to receive a coarse product, then a coarse product was washed with
distilled water and n-hexane, which was further re-crystallized in a mixed solvent of
n-hexane and dichloromethane (volume ratio4:1) to obtain pure white acerose crystal
alcohol 1 with a yield of 80% (or 67.2%) (Table 1’).
Alcohol 1: M.p.: 114.97°C; IR (KBr) (cm1): 3462, v (OH); 10001300, v (C-O-C);
1
H-NMR (CDCl3) (600 MHz)): 4.22(dd, J=6.0, 1.8Hz, 1H), 4.19(d, J=9.0Hz, 1H), 4.14
(dd, J=7.2, 5.4Hz, 1H),
4.11(d, J=2.4Hz, 1H), 4.02(d, J=13.2Hz, 1H), 3.99(d, J=9.0Hz,
1H), 3.67(d, J=6.6Hz, 1H), 2.18(s, 1H), 1.54(s, 3H), 1.52(s, 3H), 1.45(s, 3H), 1.38(s, 3H);
13
C1H-NMR (CDCl3) (150 MHz): 111.942(C-10), 109.477(C-7), 104.732(C-5),
77.212(C-3), 73.508(C-6), 72.489(C-4), 70.502(C-1), 60.982(C-2), 27.995(C-11,C-12),
26.431(C-8), 26.027(C-9).
Alcohol 2 (1,2:4,5-Di-O-cyclohexylidene-fructose):
1
The compound fructose (100 mmol, 18 g) was added into a 100 ml round-bottom
flask filled with 50 ml of dry cyclohexanone, then dripped slowly with 5 ml of
concentrated sulfuric acid at room temperature (or with 6.7 ml of perchloric acid at 0 °C)
while stirring. The resulting mixture was magnetically stirred at the given temperature for
12 h; thereafter, the pH of the solution was adjusted to 7-8 with ammonia water
(NH3·H2O). A coarse product was recovered by filtration, followed by washing with
distilled water and n-hexane to receive white solid, which was finally re-crystallized in a
mixed solvent of n-hexane and dichloromethane (volume ratio4:1) to obtain pure white
acerose crystal alcohol 2 with a yield of 65.5% (or 40.1%) (Table1’).
Alcohol 2: M.p.: 150.97 °C; IR (KBr) (cm1): 3471, v (OH); 10001300, v (C-O-C);
1
H-NMR (CDCl3) (600 MHz)): 4.17(d J=8.4Hz, 1H), 4.16(d, J=9.0Hz, 1H), 4.14 (dd,
J=31.2Hz,18.6Hz, 1H),
4.05(d, J=36.0Hz, 1H), 4.00(dd, J=18.6Hz, J=31.2Hz, 1H),
3.96(d, J=8.4Hz, 1H), 3.64(d, J=6.6Hz, 1H), 2.17(s, 1H), 1.73-1.59(m,20H);
13
C1H-NMR(CDCl3)
72.646(C-2),71.891(C-3),
(150MHz):
112.75(C-13),
71.010(C-6),
69.087(C-4),
110.324(C-5),
104.439(C-7),
61.111(C-1),
36.058(C-18),
36.039(C-14), 36.009(C-8), 35.978(C-12), 25.199(C-16), 25.184(C-10), 24.131(C-17),
24.097(C-15), 24.074(C-11), 24.039(C-9).
Synthesis of ketone compounds 1 and 2
The preparation of PCC oxidant was carried out in the following procedure. One
hundred grams of CrO3 (1.0 mol) was slowly added into a stirred solution of 6 M HCl
(1.1 mol, 184 ml) in a 500 ml glass beaker under mechanical agitation. After being
2
vigorously agitated for 5 min, the solution was cooled down to 0 °C with a salt-ice bath,
followed by a slow addition of 79.10 g of pyridine (1.0 mol) over 10 min. A vast quantity
of orange precipitate appeared which then underwent a speedy filtration at 0 °C with
Buchner funnel. The recovered orange solid was treated by drying in vacuum at 40 °C for
72 h to obtain an orange solid product with a yield of 84.4%. IR (KBr) (cm1): 3223,
3159, 3062, 2978, 2856, 2025, 1907, 1631, 606, 1537, 1485, 1377, 1330, 1249, 1200,
1167, 1053, 894, 748, 675, 607, 439.
The oxidation from alcohols to ketones by thus-synthesized PCC was carried out in
the following procedure. Five grams of 3Å molecular sieve powder that had been
predried in a vacuum oven at 200 °C for 24 h was added into the solution consisting of
4.5 mmol of white acerose crystal alcohols (1.18 g of alcohol 1 or 1.55 g of alcohol 2)
and 300 ml of dichloromethane in a 500 ml three-necked flask under stirring. Then, 3.24
g of PCC dried in vacuum at 40 °C for 72 h was added in batches at room temperature
into the above mixture over 30 min, accompanied with a color change of the reaction
mixture from khaki to shadowy. The reaction was maintained for 5 h while stirring, then
added with 200 ml of ethyl ether, followed by a filtration with a core funnel. The residue
was scrubbed with 100 ml of ethyl ether and filtrated again. The combined filtrate
underwent a solvent evaporation on a rotary evaporator at 30 °C to receive a coarse
product, which was then dissolved into dichloromethane. The purification of the product
was conducted on a silica gel column, in which a mixture of n-hexane and ethyl ether
(volume ratio1:1) was used as the eluent. After the solvent in the effluent was
evaporated off to obtain leuco-hyalo-crystal (ketone 1) or white crystal (ketone 2), which
3
was further re-crystallized in the mixture of n-hexane and dichloromethane (volume
ratio4:1) to yield pure transparent sheet crystal ketone 1 with a yield of 92.0% or sheet
crystal ketone 2 with a yield of 88.0% (Table1’).
Ketone 1 (1,2:4,5-Di-O-isopropylidene-erythro-2,3-hexdiuro-2,6-pyranose): M.p.:
99.06°C; IR (KBr) (cm1): 1751, v (C=O); 1H-NMR (CDCl3) (600 MHz)): 4.73(d,
J=5.4Hz, 1H), 4.62(d, J=9.6Hz, 1H), 4.55(ddd, J=5.4, 0.6, 0.6Hz 1H),
4.39(ddd, J=11.4,
2.4, 1.8Hz, 1H), 4.12(d, J=13.8Hz, 1H), 3.99(d, J=9Hz, 1H), 1.55(s, 3H), 1.46(s, 3H),
1.40(s, 6H); 13C1H-NMR (CDCl3) (150 MHz): 196.90(C-4), 113.76(C-5), 110.57(C-10),
104.63(C-7), 77.87(C-2), 75.82(C-6), 69.93(C-3), 60.02(C-1), 27.10(C-11), 26.45(C-12),
26.00(C-8), 25.95(C-9).
Ketone 2 (1,2:4,5-Di-O-cyclohexylidene-erythro-2,3-hexdiuro-2,6-pyranose): M.p.:
152°C; IR (KBr) (cm1): 1748, v (C=O); 1H-NMR (CDCl3) (600 MHz)): 4.75(d, J=5.4Hz,
1H), 4.59(d, J=1.8Hz, 1H), 4.55(d, J=1.2Hz 1H), 4.39(dd, J=2.4, 1.8Hz, 1H), 4.14(d,
J=13.2Hz, 1H), 3.98(d, J=9.6Hz, 1H), 1.80(d, J=6Hz , 1H), 1.79(d, J=6.6Hz, 1H), 1.70(d,
J=5.4Hz, 1H), 1.69(d, J=7.8Hz, 1H), 1.69(d, J=2.4Hz, 1H), 1.67(d, J=5.4Hz, 1H), 1.67(d,
J=5.4Hz, 1H), 1.66(d, J=4.8Hz , 1H), 1.65(d, J=9.6Hz, 1H), 1.64(d, J=6.6Hz, 1H), 1.63(d,
J=3.6Hz 1H), 1.62(d, J=5.4Hz, 1H), 1.61(d, J=5.4Hz, 1H), 1.60(d, J=5.4Hz , 1H), 1.59(d,
J=5.4Hz, 1H), 1.57(d, J=10.8Hz, 1H), 1.56(d, J=9.0Hz 1H), 1.55(d, J=7.2Hz, 1H), 1.43(d,
J=5.4Hz, 1H), 1.41(d, J=4.8Hz, 1H); 13C1H-NMR (CDCl3)(150MHz): 197.517(C-4),
114.806(C-5), 111.530(C-13), 103.947(C-7), 77.788(C-2), 75.728(C-6), 69.793(C-3),
60.467(C-1), 36.940(C-18), 36.356(C-14), 35.654(C-12), 35.494(C-8), 25.111(C-16),
25.073(C-10), 24.158(C-17), 24.108(C-15), 23.955(C-11), 24.910(C-9).
4
Structural characterization of alcohols 1,2 and ketones 1,2
Figure 1’ shows the IR spectra of raw material fructose, alcohols 1, 2 and ketones 1,
2. For as-prepared alcohols 1 and 2, a sharp absorbance band, attributed to isolated –OH
groups, appears at 3462 cm-1 for alcohol 1 and at 3471 cm-1 for alcohol 2, respectively,
obviously different from broad band at 33003600 cm-1 for fructose assigned to
associated hydroxyls with different degrees of hydrogen bonding. Some new vibration
bands emerge at 10001300 cm-1 attributed to C–O–C bond and 29002991 cm-1 to
–CH3 and –CH2 bonds for alcohol 1, and at 11201300 cm-1 assigned to C–O–C bond
and 29392850 cm-1 to –CH2 bonds for alcohol 2, respectively.
For alcohol 1, one 1H NMR peak at 2.18 ppm is assigned to OH proton, with an
intensity much weaker than that of OH protons of raw material fructose. The signals at
1.381.54 ppm are attributed to the protons of CH3. And, we can also observe from 13C
NMR spectrum of alcohol 1 that some new peaks appear at 26.0227.99 ppm, different
from 13C NMR spectrum of fructose, due to the carbon signal of –CH3 groups. Similarly,
in the 1H NMR spectrum of alcohol 2, one peak appears at 2.17 ppm assigned to OH
proton, with intensity much weaker than that of OH protons of fructose. The peaks at
1.301.74 ppm are attributed to the protons of CH2. The
13
C NMR spectrum of alcohol
shows some new peaks at 24.03936.058 ppm, which cannot be found in that of Fructose,
assigned to the carbon signal of –CH2 groups. The above results indicate the occurrence
of the catalytic condensation reaction between fructose and either acetone or
cyclohexanone.
As illustrated in Scheme 1’, alcohols 1,2 were oxidized by PCC to ketones 1,2 is. Under
5
our experimental conditions, the yield of ketones 1 and 2 reached 92.0% and 88.0% (in Table
1), respectively. Figure 1’ shows the IR spectra of ketones 1 and 2, in which the strong band
emerging at 3462 cm1 assigned to the vibration of v (OH) of alcohol 1 (at 3471 cm1 for
alcohol 2) disappears totally, and a new strong band reappears at near 1750 cm1 attributed to
C=O vibration of ketone 1 (at 1748 cm1 for ketone 2). In the 1H NMR peak at 2.18 ppm
assigned to –OH proton of alcohol 1 disappears, and one new
13
C NMR peak reappears at
196.90 ppm assigned to the carbon signal of C=O. Similarly, the 1H NMR peak at 2.17 ppm
of alcohol 2 cannot be observed in the NMR spectra of ketone 2, and one new
13
C NMR
peak emerges at 197.52 ppm attributed to the carbon signal of C=O. The above results show
the efficient oxidation from =CH–OH to =C=O radical by PCC and the structure of ketones
as depicted in Scheme 1’.
6
Table 1’. Isolated yields of alcohols and ketones
Sample
1
1
2
2
Catalyst
HClO4
H2SO4
HClO4
H2SO4
Alcohol yield (%)
67.2
80.0
40.1
65.5
Ketone yield (%)
92
92
88
88
TRANSMISSION /T%
a
γ
b
c
d
e
3900
3400
2900 2400
1900 1400
WAVENUMBER /cm -1
900
400
Figure 1’. IR spectra of fructose, alcohols 1,2, and ketones 1,2: afructose, b alcohol 1,
calcohol 2, dketone 1, eketone 2.
7
OH
O
Acetone (a)
70％HClO4，0°C
1
5
2
OH
HO
O
12
OH
HO
fructose
10
11
Acetone (b)
H2SO4， r.t.
6
O
O
O
7
O
9
4
OH
3
8
alcohol 1
1
O
CH2Cl2, r.t.
12
O
4
10
O
3
O
7
5
2
PCC
6
O
8
9
O
11
ketone 1
Cyclohexanone(a)
OH
O
0°C
70％HClO4，
1
HO
HO
O
fructose
17
3
Cyclohexanone(b)
15
H2SO4，r.t.
14
O
17
4
3
O
13
15
11
O
7
5
18
16
10
12
6
O
2
CH2Cl2, r.t.
9
alcohol 2
1
PCC
8
O
OH
O
13
16
7
4
18
OH
O
5
2
OH
6
O
8
9
O
10
12
O
11
14
ketone 2
Scheme 1’. Synthetic routes of alcohols 1,2 and ketones 1,2
8