C. Han et al. / Tetrahedron 67 (2011) 9622e9626
9625
ethyl acetate (50 mLꢂ3). The combined organic extracts were dried
over anhydrous Na2SO4, and evaporated in vacuo. The residue was
subjected to column chromatography on silica-gel (CH2Cl2/
EtOAc¼2/1 as an eluent) to give 1,6-diphenyl-1,5-hexadiene-3,4-
0.004 mmol) and NaClO (16 mL, 0.04 mmol), and the mixture was
stirred for 4 h at room temperature in the dark. The reaction was
quenched with satd aqueous Na2SO3. The mixture was extracted
with CH2Cl2 (10 mLꢂ3). The combined organic extracts were dried
over anhydrous Na2SO4, and concentrated in vacuo. The residue
was subjected to column chromatography on silica-gel (eluent;
toluene) to give benzenepropenal 3 (2.2 mg, 84%) and benzene-
diol 2 (1.1 g, 83%) as a white solid. 1H NMR (CDCl3):
d 2.45 (br s,
2H), 4.26 (m, 2H), 6.25 (dd, J¼5.5, 15.8 Hz, 2H), 6.71 (d, J¼15.8 Hz),
7.23 (m, 2H), 7.29 (t, J¼7.6 Hz, 4H), 7.36 (J¼7.6 Hz, 4H). HRMS (ESI)
calcd for [MþNa]þ (C18H18O2Na) m/z 289.1204. Found 289.1210.
propanal 5 (2.1 mg, 78%); 1H NMR (CDCl3)
d 2.79 (m, 2H), 2.96 (m,
2H), 7.19 (m, 3H), 7.29 (m, 2H), 9.81 (br s, 1H). HR-ESIMS calcd for
3.3. Synthesis of 1,6-diphenyl-1-hexene-3, 4-diol (4)
[MþH]þ (C9H11O) m/z 135.081. Found 135.086.
1,6-Diphenyl-1,5-hexadiene-3,4-diol 2 (5.3 mg, 0.02 mmol) was
dissolved in MeOH (1.0 mL), and 0.4 mg of Rh/C (wt 5%) was added.
The solution was stirred under a hydrogen atmosphere (balloon) for
1 h at room temperature. The catalyst was removed through a filter
3.7. Methanolysis of symbiodinolide
To a stirred solution of symbiodinolide (4.4 mg, 1.5
mmol) in
MeOH (3.6 mL) was added Et3N (1.1 mL). After the reaction mixture
was stirred for 46 h at room temperature, it was concentrated under
reduced pressure to give the seco ester of symbiodinolide (4.5 mg,
100%) as a colorless solid that was sufficientlypure for the next stage.
HRMS (ESI) calcd for (Mþ2Na)2þ (C69H118N0.5Na1.5O29S0.5) m/z
1468.2481. Found 1468.2497.
(Minisart RC 4, 0.45 mm, Goettingen, Germany), and the filtrate was
evaporated and purified by HPLC [Develosil ODS-HG-5 (Ø
10ꢂ250 mm), 60% aqueous MeCN, flow rate 2 mL/min, RI detection]
to give monoallyl vic-diol 4 (3.2 mg, 60%, tR¼15.93e16.77 min) as
a white solid. 1H NMR (CDCl3):
d
1.71 (dddd, J¼5.2, 9.3, 9.8, 13.8 Hz,
1H), 1.86 (dddd, J¼3.4, 7.2, 10.3, 13.8 Hz, 1H), 2.66 (ddd, J¼7.2, 9.8,
13.6 Hz,1H), 2.84 (ddd, J¼5.2,10.3,13.6 Hz,1H), 3.53 (ddd, J¼3.4, 5.7,
9.3 Hz, 1H), 4.09 (dd, J¼5.7, 6.9 Hz, 1H), 6.26 (dd, J¼6.8, 15.8 Hz, 1H),
6.62 (d, J¼15.8 Hz, 1H), 7.12 (t, J¼7.3 Hz, 1H), 7.17e7.23 (m, 5H), 7.28
(t, J¼7.9 Hz, 2H), 7.38 (J¼7.9 Hz, 2H). HRMS (ESI) calcd for [MþNa]þ
(C18H20O2Na) m/z 291.1357. Found 291.1361.
3.8. Grubbs II complex-catalyzed cleavage of seco
symbiodinolide (6) using NaClO
A solution of seco symbiodinolide (6) (3.4 mg, 1.17
mmol) in
MeOH (0.3 mL) was degassed three times and then placed under an
argon atmosphere. To the above stirred solution was added the
second-generation Grubbs catalyst (29.4 mM in dichloromethane,
3.4. Stoichiometric oxidation of 1,6-diphenyl-1,5-hexadiene-
3,4-diol (2) to cinnamaldehyde (3)
4 mL, 0.12 mmol) and sodium hypochlorite solution (3 mL, 7.9 mmol),
and the mixture was stirred for 3 h at room temperature in the dark.
The reaction mixture was concentrated in vacuo, and the residue
was separated by RP-HPLC [Develosil ODS-HG-5, Ø 10ꢂ250 mm,
Nomura Chemical Co., Aichi, Japan, 20e50% aqueous MeCN, 60 min
A solution of 1,6-diphenyl-1,5-hexadiene-3,4-diol 2 (5.3 mg,
0.02 mmol) in anhydrous MeOH (0.8 mL) was degassed three times
and then placed under an argon atmosphere. To the above stirred
solution was added the ruthenium complex (0.02 mmol) in 0.2 mL
of DCM, and the mixture was stirred for 4 h at room temperature in
the dark. The reaction mixture was concentrated in vacuo, and the
residue was subjected to column chromatography on silica-gel
(eluent; toluene) to give trans-cinnamaldehyde 3: 3.4 mg (64%
yield by RuCl2(PPh3)3, 1.8 mg (34% yield by Grubbs I catalyst), trace
linear gradient, flow rate 2.0 mL/min, RI detection] to give ab
,
gd-
unsaturated aldehyde 7 (0.3 mg, 86%, tR¼9.13e10.07 min) and
a,b
-
unsaturated aldehyde 8 (2.3 mg, 76%, tR¼25.93e29.87 min).
3.8.1. ab,
gd-Unsaturated aldehyde 7 (C1eC13 fragment). 1H NMR
(CD3OD)
d
1.74 (m, 2H), 2.44 (dd, J¼8.7, 15.3 Hz, 1H), 2.47 and 2.52
(RuCl3), NR (RuO2). 1H NMR (CDCL3)
d
6.73 (dd, J¼7.6, 15.8 Hz, 1H),
(m, 2H), 2.56 (dd, J¼4.6,15.3 Hz,1H), 3.66 (m,1H), 3.67 (s, 3H, OMe),
3.81 (m, 1H), 3.89 (m, 1H), 4.23 (m, 1H), 6.09 (dd, J¼7.8, 15.2 Hz, 1H),
6.46 (m, 2H), 7.29 (dd, J¼10.1,15.2 Hz,1H), 9.49 (d, J¼7.8 Hz,1H); HR
ESI-TOF-MS m/z 325.1194 (MþNa)þ, calcd for C14H22O7Na:
325.1263.
7.44 (m, 3H), 7.49 (d, J¼15.8 Hz, 1H), 7.57 (m, 2H), 9.71 (d, J¼7.6 Hz,
1H). HR-ESIMS calcd for [MþH]þ (C9H9O) m/z 133.0656. Found
133.0653.
3.5. Typical procedure for screening of oxidants for the
catalytic cleavage of allyl vic-alcohol (2)
3.8.2.
a
,
b
-Unsaturated aldehyde 8 (C14ꢀC250 fragment). A colorless
solid; 1H NMR (CD3OD)
d
0.90 (t, J¼6.9 Hz, 3H, H250), 0.95 (d,
The solution of diallyl vic-diol
2
(5.3 mg, 0.02 mmol) in
J¼6.4 Hz, 3H, C70eMe), 1.01 (d, J¼6.5 Hz, 3H, C53eMe), 1.06 (d,
J¼6.9 Hz, 3H, C95eMe), 1.16 (m, 2H, H84a), 1.25 (m, 1H, H90a), 1.29
(m, 2H, H240), 1.30 (m, 2H, H230), 1.31 (m, 2H, H220), 1.33 (m, 2H,
H210), 1.42 (m, 2H, H190), 1.45 (m, 2H, H96), 1.45 (s, 3H, C30eMe),
1.37 and 1.45 (m, 2H, H52), 1.50 (m, 2H, H200), 1.51 (m, 2H, H80),
1.52 (m, 2H, H63), 1.53 (m, 2H, H78a, H92a), 1.38 and 1.58 (m, 4H,
H86, H88), 1.59 (m, 4H, H82, H84b, H90b), 1.30 and 1.60 (m, 2H,
H81), 1.62 (m, 1H, H74a), 1.66 (m, 2H, H45), 1.67 (m, 1H, H78b), 1.43
and 1.68 (m, 2H, H60), 1.70 (s, 6H, C38eMe, C90eMe), 1.70 (m, 2H,
H62a, H92b), 1.59 and 1.72 (m, 2H, H50), 1.64 and 1.72 (m, 2H, H70),
1.54 and 1.87 (m, 2H, H85), 1.49 and 1.89 (m, 2H, H31), 1.94 (m, 3H,
H62b, H89),1.49 and 1.95 (m, 2H, H100),1.49 and 1.97 (m, 2H, H160),
2.06 (m, 2H, H74b, H95), 2.17 and 2.21 (m, 2H, H39), 2.23 (m, 4H,
H43, H60), 2.17 and 2.26 (m, 2H, H35), 2.18 and 2.26 (m, 2H, H100),
2.28 and 2.37 (m, 2H, H25), 2.42 (m, 2H, H20), 2.43 (m, 1H, H53),
2.55 (m, 1H, H70), 2.33 and 2.63 (m, 2H, H68), 2.65 (d, J¼6.5 Hz, 1H,
H29), 2.93 (dd, J¼2.4, 6.2 Hz, 1H, H28), 2.98 (dd, J¼2.4, 4.5 Hz, 1H,
H27), 3.04 (t, J¼8.6 Hz, 1H, H72), 3.12 (dd, J¼1.7, 7.2 Hz, 1H, H94),
3.18 (m, 2H, H76, 98), 3.25 (m, 1H, H40), 3.37 (m, 1H, H180), 3.49 (m,
dichloromethane (0.9 mL) was degassed and then placed under an
argon atmosphere. To the above stirred solution was added the
second-generation catalyst (20 mM in dichloromethane, 0.1 mL,
0.002 mmol) and NaClO (16 mL, 0.04 mmol), and the mixture was
stirred for 4 h at room temperature in the dark. The reaction was
quenched with satd aqueous Na2SO3. The mixture was extracted
with CH2Cl2 (10 mLꢂ3). The combined organic extracts were dried
over anhydrous Na2SO4, concentrated in vacuo. The residue was
subjected to column chromatography on silica-gel (eluent; toluene)
to give trans-cinnamaldehyde 3 (4.8 mg, 90%) as a yellow liquid.
3.6. Catalytic cleavage of monoallyl vic-alcohol (4) to
benzenepropenal (3) and benzenepropanal (5)
The solution of monoallyl vic-diol 4 (5.4 mg, 0.02 mmol) in
dichloromethane (0.9 mL) was degassed and then placed under an
argon atmosphere. To the above stirred solution was added the
second-generation catalyst (40 mM in dichloromethane, 0.1 mL,