The Journal of Organic Chemistry
Article
NMR (100 MHz, CDCl3) δ 188.1 (C), 182.7 (C), 170.4 (C), 154.8
(C), 145.9 (C), 131.8 (CH), 128.8 (CH), 121.8 (CH), 112.9 (CH),
84.6 (C), 77.1 (CH), 26.9 (CH2), 22.5 (CH3), 21.6 (CH3), 21.0
(CH3), 18.6 (CH2), 15.6 (CH3), −1.8 (CH3 × 3); HRMS (ESI) calcd
for C20H33O5Si 381.2097 (M+ + H), found 381.2081.
was prepared from benzoate 4c (16.6 mg, 0.04 mmol); yellow oil. The
diastereomixture of 12c were partially separated with HPLC column
(Mightysil, 25% AcOEt−hexane, 10 mL/min). anti-Quinone 12c: IR
1
(neat) 3484, 2979, 1716, 1654 cm−1; H NMR (400 MHz, CDCl3) δ
8.04 (2H, d, J = 8.0 Hz), 7.58 (1H, t, J = 8.0 Hz), 7.45 (2H, t, J = 8.0
Hz), 6.51 (1H, s), 6.43 (1H, d, J = 1.6 Hz), 5.81 (1H, ddd, J = 17.2,
10.0, and 8.4 Hz), 5.17 (1H, d, J = 17.2 Hz), 5.16 (1H, d, J = 10.0 Hz),
5.20−5.10 (1H, m), 3.48 (1H, dt, J = 5.6 and 8.4 Hz), 2.12 (1H, ddd, J
= 14.0, 10.0, and 5.6 Hz), 2.01 (1H, ddd, J = 14.0, 8.4, and 1.6 Hz),
1.87 (3H, d, J = 1.6 Hz), 1.83 (1H, s, D2O exchangeable), 1.27 (3H,
s), 1.25 (3H, s); 13C NMR (100 MHz, CDCl3) δ 188.0 (C), 186.7
(C), 166.4 (C), 150.2 (C), 145.0 (C), 137.1 (CH), 133.6 (CH), 133.2
(CH), 132.3 (CH), 129.8 (CH × 2), 129.8 (C), 128.5 (CH × 2),
118.2 (CH2), 78.4 (CH), 72.6 (C), 40.4 (CH), 33.7 (CH2), 26.3
(CH3), 25.4 (CH3), 15.2 (CH3); HRMS (ESI) calcd for C22H25O5
369.1702 (M+ + H), found 369.1707. syn-Quinone 12c: IR (neat)
(Z)-2-Methyl-5-(2-methyl-3-(triisopropylsilyloxy)-7-
(trimethylsilyl)hept-5-en-2-yloxy)cyclohexa-2,5-diene-1,4-
dione (4e). By the same procedure described for (S)-4b, quinone 4e
(222 mg, 50%) was prepared from silyl ether 11e (472 mg, 0.90
1
mmol): yield 50%; yellow oil. IR (neat) 2946, 1599, 1385 cm−1; H
NMR (400 MHz, CDCl3) δ 6.51 (1H, d, J = 1.6 Hz), 6.15 (1H, s),
5.51−5.40 (2H, m), 4.08 (1H, t, J = 5.6 Hz), 2.53−2.46 (1H, m),
2.29−2.21 (1H, m), 2.04 (3H, d, J = 1.6 Hz), 1.54 (3H, s), 1.58−1.44
(2H, m), 1.44 (3H, s), 1.20−1.00 (21H, m), 0.00 (9H, s); 13C NMR
(100 MHz, CDCl3) δ 188.3 (C), 182.8 (C), 155.3 (C), 145.8 (C),
131.7 (CH), 126.9 (CH), 123.9 (CH), 112.0 (CH), 87.4 (C), 78.1
(CH), 31.1 (CH2), 23.0 (CH3), 20.1 (CH3), 18.6 (CH2), 18.3 (CH3 ×
6), 17.7 (CH3), 13.1 (CH × 3), −1.7 (CH3 × 3); HRMS (ESI) calcd
for C27H49O4Si2 493.3169 (M+ + H), found 493.3165.
1
3503, 2979, 1717, 1655 cm−1; H NMR (400 MHz, CDCl3) δ 7.98
(2H, d, J = 8.0 Hz), 7.58 (1H, t, J = 8.0 Hz), 7.45 (2H, t, J = 8.0 Hz),
6.52 (1H, q, J = 2.0 Hz), 6.49 (1H, s), 5.82 (1H, ddd, J = 17.2, 10.0,
and 8.0 Hz), 5.07 (1H, d, J = 17.2 Hz), 5.02 (1H, dd, J = 10.0 and 2.8
Hz), 5.01 (1H, d, J = 10.0 Hz), 3.58 (1H, dt, J = 5.6 and 8.0 Hz), 2.20
(1H, ddd, J = 14.8, 8.0, and 2.8 Hz), 2.12 (1H, ddd, J = 14.8, 10.0, and
5.6 Hz), 1.95 (3H, d, J = 2.0 Hz), 1.79 (1H, brs, D2O exchangeable),
1.26 (6H, s); 13C NMR (100 MHz, CDCl3) δ 188.0 (C), 186.8 (C),
166.2 (C), 149.5 (C), 145.2 (C), 138.0 (CH), 133.8 (CH), 133.1
(CH), 132.5 (CH), 129.9 (C), 129.7 (CH × 2), 128.4 (CH × 2),
116.7 (CH2), 77.6 (CH), 72.6 (C), 39.4 (CH), 33.0 (CH2), 26.1
(CH3), 25.6 (CH3), 15.3 (CH3); HRMS (ESI) calcd for C22H25O5
369.1702 (M+ + H), found 369.1713.
(3S,5R)-5-(2,5-Dihydroxy-4-methylphenyl)-2-hydroxy-2-
methylhept-6-en-3-yl Acetate (3S,5R)-25. To a stirred solution of
quinone (3S,5R)-12b (63.5 mg, 0.21 mmol) in THF (1 mL) was
added Na2S2O4 (108 mg, 0.62 mol) in H2O (0.1 mL) at 0 °C. After
stirring was continued for 2.5 h at rt, the reaction mixture was
quenched with saturated aqueous NH4Cl and extracted with AcOEt.
The combined extracts were washed with saturated aqueous NaCl.
The residue upon workup was chromatographed on silica gel with
hexane−AcOEt (1:1 v/v) as eluent to give hydroquinone (3S,5R)-25
(64.7 mg, 99%) as colorless crystals. Mp 192.2−193.6 °C (MeOH);
[α] −6.4 (c 0.29 CHCl3); IR (neat) 3379, 2979, 1712, 1418, 1384
cm−1; 1H NMR (400 MHz, CDCl3) δ 6.59 (1H, s), 6.56 (1H, s), 5.92
(1H, ddd, J = 17.4, 10.4, and 7.2 Hz), 5.15 (1H, dd, J = 10.4 and 1.2
Hz), 5.13 (1H, dd, J = 17.4 and 1.2 Hz), 4.93 (1H, dd, J = 9.6 and 2.4
Hz), 4.71 (1H, brs, D2O exchangeable), 4.57 (1H, brs, D2O
exchangeable), 3.52 (1H, dt, J = 7.2 and 5.6 Hz), 2.17 (3H, s),
2.12−2.02 (1H, m), 2.05−1.92 (1H, m), 1.97 (3H, s), 1.82 (1H, brs,
D2O exchangeable), 1.22 (3H, s), 1.20 (3H, s); 13C NMR (100 MHz,
CDCl3) δ 171.6 (C), 147.9 (C), 146.6 (C), 140.0 (CH), 128.0 (C),
123.0 (C), 118.9 (CH), 115.8 (CH2), 114.6 (CH), 78.3 (CH), 72.8
(C), 40.3 (CH), 33.8 (CH2), 26.3 (CH3), 25.2 (CH3), 20.9 (CH3),
15.4 (CH3); HRMS (ESI) calcd for C17H25O5 309.1702 (M+ + H),
found 309.1695.
(3S,5R)-2-Hydroxy-2-methyl-5-(4-methyl-3,6-dioxocyclo-
hexa-1,4-dienyl)hept-6-en-3-yl Acetate (12b). To a stirred
solution of quinone (S)-4b (103 mg, 0.27 mmol) in (CH3)2CHCN
(1 mL) was added dropwise TBSOTf (0.12 mL, 0.54 mol) at −10 °C.
After stirring was continued for 0.5 h at the same temperature, the
reaction mixture was quenched with saturated aqueous NaHCO3 and
extracted with AcOEt. The combined extracts were washed with
saturated aqueous NaCl. The residue upon workup was chromato-
graphed on silica gel with hexane−AcOEt (7:3 v/v) as eluent to give
quinone (3S,5R)-12b (55.4 mg, 67%, dr = 7:1) as a yellow oil. The
diastereomixture of (3S,5R)-12b were partially separated with HPLC
column (Mightysil, 20% AcOEt−hexane, 8 mL/min). anti-Quinone
(3S,5R)-12b: [α] −9.7 (c 0.49 CHCl3); IR (neat) 3471, 2979, 1731,
1656, 1376, 1242 cm−1; 1H NMR (400 MHz, CDCl3) δ 6.59 (1H, d, J
= 0.8 Hz), 6.54 (1H, s), 5.74 (1H, ddd, J = 17.2, 10.0, and 4.0 Hz),
5.20 (1H, d, J = 10.0 Hz), 5.16 (1H, d, J = 17.2 Hz), 4.88 (1H, dd, J =
10.4 and 2.0 Hz), 3.43 (1H, dt, J = 9.2 and 4.0 Hz), 2.14 (3H, s), 2.04
(3H, d, J = 0.8 Hz), 1.93−1.77 (2H, m), 1.75 (1H, s, D2O
exchangeable), 1.19 (3H, s), 1.18 (3H, s); 13C NMR (100 MHz,
CDCl3) δ 188.1 (C), 186.6 (C), 171.0 (C), 150.6 (C), 145.3 (C),
136.7 (CH), 133.7 (CH), 132.0 (CH), 118.6 (CH2), 77.4 (CH), 72.4
(C), 38.9 (CH), 33.6 (CH2), 26.4 (CH3), 25.2 (CH3), 21.0 (CH3),
15.3 (CH3); HRMS (ESI) calcd for C17H23O5 307.1545 (M+ + H),
found 307.1553. syn-Quinone (3S, 5S)-12b: IR (neat) 3427, 2978,
1732, 1656, 1385 cm−1; 1H NMR (400 MHz, CDCl3) δ 6.60 (1H, d, J
= 1.6 Hz), 6.49 (1H, s), 5.77 (1H, ddd, J = 17.2, 10.0, and 7.6 Hz),
5.08 (1H, d, J = 17.2 Hz), 5.06 (1H, d, J = 10.0 Hz), 4.73 (1H, dd, J =
9.6 and 3.6 Hz), 3.56 (1H, dt, J = 7.6 and 7.2 Hz), 2.06 (3H, s), 2.04
(3H, d, J = 1.6 Hz), 2.02−1.96 (2H, m), 1.62 (1H, s, D2O
exchangeable), 1.18 (3H, s), 1.17 (3H, s); 13C NMR (100 MHz,
CDCl3) δ 188.1 (C), 186.7 (C), 170.9 (C), 149.5 (C), 145.4 (C),
138.5 (CH), 133.8 (CH), 132.3 (CH), 116.3 (CH2), 77.2 (CH), 72.3
(C), 38.5 (CH), 32.8 (CH2), 26.4 (CH3), 25.2 (CH3), 21.0 (CH3),
15.4 (CH3); HRMS (ESI) calcd for C17H23O5 307.1545 (M+ + H),
found 307.1541.
(3S,5R)-2-(2,3-Dihydroxy-2-methylhept-6-en-5-yl)-5-methyl-
benzene-1,4-diol (3S,5R)-26. To a stirred solution of hydroquinone
(3S,5R)-25 (10.2 mg, 0.03 mmol) in THF (1 mL) was added dropwise
0.97 M solution of DIBAH in hexane (0.14 mL, 0.13 mmol) at 0 °C.
After stirring was continued for 1.5 h at the same temperature, the
reaction mixture was quenched with MeOH. After filtration through a
Celite pad, the resulting solution was extracted with AcOEt. The
combined extracts were washed with saturated aqueous NaCl. The
residue upon workup was chromatographed on silica gel with hexane−
AcOEt (35:65 v/v) as eluent to give tetraol (3S,5R)-26 (5.9 mg, 67%)
as a colorless oil. [α] −48.7 (c 0.66 acetone); IR (neat) 3388, 2976,
2-Methyl-2-(4-methyl-3,6-dioxocyclohexa-1,4-dienyloxy)-
hept-6-en-3-yl Acetate (13b). 13b (15.7 mg, 19%) was obtained as
yellow crystals; Mp 102.1−102.4 °C (hexane); IR (KBr) 2983, 1736,
1674, 1651, 1606 cm−1; 1H NMR (400 MHz, CDCl3) δ 6.52 (1H, q, J
= 1.6 Hz), 6.15 (1H, s), 5.80 (1H, ddt, J = 16.8, 10.0, and 6.8 Hz), 5.18
(1H, dd, J = 10.0 and 2.8 Hz), 5.04 (1H, dd, J = 16.8 and 1.6 Hz), 4.99
(1H, dd, J = 10.0 and 1.6 Hz), 2.11 (3H, s), 2.13−2.07 (2H, m), 2.04
(3H, d, J = 1.6 Hz), 1.85−1.68 (2H, m), 1.46 (6H, s); 13C NMR (100
MHz, CDCl3) δ 188.0 (C), 182.7 (C), 170.4 (C), 154.8 (C), 145.9
(C), 137.3 (CH), 131.8 (CH), 115.4 (CH2), 113.1 (CH), 84.7 (C),
76.7 (CH), 30.0 (CH2), 28.5 (CH2), 22.3 (CH3), 21.6 (CH3), 20.9
(CH3), 15.5 (CH3); HRMS (ESI) calcd for C17H22O5Na 329.1365
(M+ + Na), found 329.1381.
1
1415, 1384 cm−1; H NMR (400 MHz, CD3COCD3) δ 7.30 (1H, s,
D2O exchangeable), 7.19 (1H, s, D2O exchangeable), 6.47 (1H, s),
6.44 (1H, s), 5.85 (1H, ddd, J = 17.2, 10.4, and 8.4 Hz), 4.94 (1H, dd,
J = 17.2 and 2.0 Hz), 4.86 (1H, dd, J = 10.4 and 2.0 Hz), 3.76 (1H, td,
J = 8.4 and 3.6 Hz), 3.45 (1H, d, J = 5.2 Hz, D2O exchangeable), 3.30
(1H, ddd, J = 10.4, 5.2, and 2.0 Hz), 3.23 (1H, s, D2O exchangeable),
1.96 (3H, s), 1.95 (1H, ddd, J = 13.6, 8.4, and 2.0 Hz), 1.38 (1H, ddd,
2-Hydroxy-2-methyl-5-(4-methyl-3,6-dioxocyclohexa-1,4-
dienyl)hept-6-en-3-yl Benzoate (12c). By following the same
procedure described for (S)-12b, quinone 12c (9.4 mg, 68%, dr = 8:1)
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dx.doi.org/10.1021/jo3016055 | J. Org. Chem. 2012, 77, 8231−8243