The Journal of Organic Chemistry
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8.7 Hz), 9.55 (1H, s); HRESIMS m/z 523.2978 [M + H]+ (calcd for
C34H38N2O3 + H, 523.2961).
4,4′-((2R,3R,4R,5S)-3,4-Bis(4-methoxyphenyl)tetrahydrofuran-
2,5-diyl)bis(N,N-dimethylaniline) (14k). Yellowish oil, and subse-
quently, yellowish needles from hexanes/CH2Cl2; mp 175−178 °C;
1H NMR (CDCl3, 400 MHz) δ 2.87 (6H, s), 2.96 (6H, s), 3.53 (1H, t,
6.87 (1H, s), 7.08 (2H, d, J = 8.2 Hz), 7.19 (2H, d, J = 8.7 Hz), 7.29
(2H, d, J = 8.2 Hz); HRESIMS m/z 586.4035 [M + H]+ (calcd for
C42H51NO + H, 586.4049).
(4bR,5R,9bR,10R)-5,10-Bis(4-(tert-butyl)phenyl)-1,3,6,8-tetra-
methyl-4b,5,9b,10-tetrahydroindeno[2,1-a]indene (18p). Colorless
1
oil; H NMR (CDCl3, 400 MHz) δ 1.26 (18H, s), 1.94 (6H, s), 2.34
(6H, s), 4.00 (2H, s), 4.52 (2H, s), 6.76 (2H, s), 6.99 (4H, d, J = 8.7
Hz), 7.20 (2H, s), 7.23 (4H, d, J = 8.7 Hz); HRESIMS m/z 527.3687
[M + H]+ (calcd for C40H46 + H, 527.3678).
J = 9.9 Hz), 3.67 (3H, s), 3.74 (3H, s), 4.02 (1H, dd, J = 9.9, 8.5 Hz),
5.10 (1H, d, J = 9.9 Hz), 5.54 (1H, d, J = 8.5 Hz), 6.55 (4H, d, J = 8.3
Hz), 6.72 (2H, d, J = 8.7 Hz), 6.76 (2H, d, J = 8.3 Hz), 6.78 (2H, d, J
= 8.3 Hz), 7.01 (2H, d, J = 8.3 Hz), 7.10 (2H, d, J = 8.3 Hz), 7.30 (2H,
d, J = 8.7 Hz); HRESIMS m/z 561.2516 [M + K]+ (calcd for
C34H38N2O3+ K, 561.2520).
Anodic Oxidation of 17 in MeCN/0.2 M LiClO4. Controlled
potential electrolysis of 17 (+1.09 V) yielded a mixture, which on
centrifugal preparative TLC (SiO2, 4:1 hexanes/CH2Cl2 to 100%
CH2Cl2) gave 17c (6.5 mg, 15%) and a mixture of acetamides (17m
and 17n). Crystals were obtained from MeOH/CH2Cl2, which were
shown by X-ray analysis to be 1:1 cocrystals of the epimers. HPLC
(Chiralpak IA column, 10% i-PrOH/n-hexane, 0.5 mL/min) of the
acetamide mixture gave 17m (16.5 mg, 32%) and 17n (16.5 mg, 32%).
See Table 4, entry 1.
Anodic Oxidation of 21 in MeCN/0.2 M LiClO4. Controlled
potential electrolysis of 21 (+0.76 V) yielded a mixture, which on
centrifugal preparative TLC (SiO2, 1:2 hexanes/CH2Cl2 to 100%
CH2Cl2) gave a semipure fraction. This fraction was loaded onto a
Sephedex LH20 column and eluted with 20% MeCN/MeOH to give
21p (14.9 mg, 30%) and 21s (25.4 mg, 51%). See Table 5, entry 1.
(4bR,5R,9bR,10R)-2,3,7,8-Tetramethoxy-5,10-bis(4-methoxy-
phenyl)-4b,5,9b,10-tetrahydroindeno[2,1-a]indene (21p). Light yel-
lowish oil, and subsequently, colorless block crystals from hexanes/
Et2O; mp 181−183 °C; 1H NMR (CDCl3, 400 MHz) δ 3.73 (6H, s),
3.79 (6H, s), 3.92 (6H, s), 4.05 (2H, br s), 4.44 (2H, br s), 6.52 (2H,
s), 6.86 (4H, d, J = 8.6 Hz), 6.91 (2H, s), 7.09 (4H, d, J = 8.6 Hz);
HRESIMS m/z 539.2419 [M + H]+ (calcd for C34H34O6 + H,
539.2428).
(1R,2R)-7-Methyl-1,2,3-tri-p-tolyl-1,2-dihydronaphthalene (17c).
Light yellowish oil, and subsequently, colorless block crystals from
hexanes/Et2O; mp 134−139 °C; 1H NMR (CDCl3, 400 MHz) δ 2.24
(3H, s), 2.29 (9H, s), 4.22 (1H, s), 4.25 (1H, s), 6.84 (1H, s), 7.04
(1H, m), 7.05 (6H, m), 7.14 (2H, d, J = 8.2 Hz), 7.21 (1H, m), 7.24
(2H, d, J = 7.7 Hz), 7.25 (1H, d, J = 7.7 Hz), 7.32 (2H, d, J = 8.2 Hz);
HRESIMS m/z 415.2431 [M + H]+ (calcd for C32H30 + H, 415.2420).
N-((S)-((1R,2S,3R)-5-Methyl-2,3-di-p-tolyl-2,3-dihydro-1H-inden-
(5S,10S,11S,12R)-2,3,7,8-Tetramethoxy-11,12-bis(4-methoxy-
phenyl)-10,11-dihydro-5H-5,10-methanodibenzo[a,d][7]annulene
1
(21s). Light yellowish oil; H NMR (CDCl3, 400 MHz) δ 3.39 (1H,
s), 3.64 (3H, s), 3.67 (3H, s), 3.80 (4H, s), 3.83 (3H, s), 3.87 (3H, s),
3.92 (1H, s), 3.93 (3H, s), 4.23 (1H, s), 6.41 (1H, s), 6.65 (2H, d, J =
8.4 Hz), 6.74 (1H, s), 6.75 (1H, s), 6.85 (2H, d, J = 8.4 Hz), 6.87 (2H,
d, J = 8.6 Hz),7.00 (1H, s), 7.18 (2H, d, J = 8.6 Hz); HRESIMS m/z
539.2406 [M + H]+ (calcd for C34H34O6 + H, 539.2428).
Anodic Oxidation of 24 in MeCN/0.2 M LiClO4. Controlled
potential electrolysis of 24 (+0.75 V) yielded a mixture, which on
centrifugal preparative TLC (SiO2, 100% CH2Cl2 to 5% MeOH/
CH2Cl2), followed by HPLC (Luna Phenyl−Hexyl column, 60%
H2O/MeCN to 40% H2O/MeCN in 7 min, 15 mL/min), gave 24a
(3.1 mg, 6%), 24p (9.0 mg, 16%), and 24s (18.0 mg, 36%). See Table
5, entry 4.
4,4′-((2S,3R,4R,5S)-3,4-Bis(3,4-dimethoxyphenyl)-
tetrahydrofuran-2,5-diyl)diphenol (24a). Light yellowish oil; 1H
NMR (CDCl3, 400 MHz) δ 3.50 (2H, dd, J = 6.3, 2.7 Hz), 3.69 (6H,
s), 3.79 (6H, s), 5.24 (2H, dd, J = 6.3, 2.7 Hz), 5.32 (2H, br s), 6.47
(2H, d, J = 1.5 Hz), 6.64 (2H, dd, J = 8.4, 1.5 Hz), 6.69 (2H, d, J = 8.4
Hz), 6.74 (4H, d, J = 8.6 Hz), 7.17 (4H, d, J = 8.6 Hz); HRESIMS m/
z 529.2205 [M + H]+ (calcd for C32H32O7 + H, 529.2226).
4,4′-((4bR,5R,9bR,10R)-2,3,7,8-Tetramethoxy-4b,5,9b,10-
tetrahydroindeno[2,1-a]indene-5,10-diyl)diphenol (24p). Light yel-
lowish oil; 1H NMR (CDCl3, 400 MHz) δ 3.72 (6H, s), 3.90 (6H, s),
4.00 (2H, s), 4.39 (2H, s), 5.05 (2H, br s), 6.50 (2H, s), 6.77 (4H, d, J
= 8.6 Hz), 6.88 (2H, s), 7.00 (4H, d, J = 8.6 Hz); HRESIMS m/z
511.2121 [M + H]+ (calcd for C32H30O6 + H, 511.2115).
4,4′-((5S,10S,11S,12R)-2,3,7,8-Tetramethoxy-10,11-dihydro-5H-
5,10-methanodibenzo[a,d][7]annulene-11,12-diyl)diphenol (24s).
Light yellowish oil, and subsequently, light yellowish block crystals
from hexanes/acetone; mp 164−166 °C; 1H NMR (CDCl3, 400
MHz) δ 3.33 (1H, s), 3.61 (3H, s), 3.73 (1H, s), 3.79 (3H, s), 3.84
(3H, s), 3.87 (1H, s), 3.90 (3H, s), 4.18 (1H, s), 5.57 (1H, br s), 5.77
(1H, br s), 6.39 (1H, s), 6.56 (2H, d, J = 8.6 Hz), 6.72 (2H, s), 6.75
(2H, d, J = 8.6 Hz), 6.77 (2H, d, J = 8.6 Hz), 6.96 (1H, s), 7.07 (2H, d,
J = 8.6 Hz); HRESIMS m/z 511.2120 [M + H]+ (calcd for C32H30O6
+ H, 511.2115).
1
1-yl)(p-tolyl)methyl)acetamide (17m). Light yellowish oil; H NMR
(CDCl3, 400 MHz) δ 1.54 (3H, s), 2.23 (3H, s), 2.33 (6H, s), 2.38
(3H, s), 3.35 (1H, t, J = 9.3 Hz), 4.09 (1H, d, J = 9.3 Hz), 4.17 (1H, d,
J = 9.3 Hz), 5.31, (1H, t, J = 9.3 Hz), 5.44 (1H, br s), 6.34 (1H, d, J =
7.4 Hz), 6.71 (1H, s), 6.83 (2H, d, J = 7.4 Hz), 6.91 (2H, d, J = 7.7
Hz), 7.02 (2H, d, J = 8.2 Hz), 7.07 (4H, m), 7.17 (2H, d, J = 7.7 Hz),
7.28 (2H, d, J = 7.7 Hz); HRESIMS m/z 474.2784 [M + H]+ (calcd
for C34H35NO + H, 474.2791).
N-((R)-((1R,2S,3R)-5-Methyl-2,3-di-p-tolyl-2,3-dihydro-1H-inden-
1
1-yl)(p-tolyl)methyl)acetamide (17n). Light yellowish oil; H NMR
(CDCl3, 400 MHz) δ 1.94 (3H, s), 2.26 (3H, s), 2.30 (3H, s), 2.32
(6H, s), 3.25 (1H, t, J = 10.0 Hz), 4.00 (1H, br d, J = 9.0 Hz), 4.32
(1H, d, J = 10.0 Hz), 5.48 (1H, dd, J = 9.0, 2.3 Hz), 5.73 (1H, d, J =
2.3 Hz), 6.75 (1H, br s), 6.84 (2H, d, J = 7.9 Hz), 6.86 (1H, br d, J =
8.2 Hz), 6.96 (1H, d, J = 8.2 Hz), 7.03 (2H, d, J = 7.9 Hz), 7.12 (8H,
m); HRESIMS m/z 474.2786 [M + H]+ (calcd for C34H35NO + H,
474.2791).
Anodic Oxidation of 18 in MeCN/0.2 M LiClO4. Controlled
potential electrolysis of 18 (+1.18 V) yielded a mixture, which on
centrifugal preparative TLC (SiO2, 4:1 hexanes/CH2Cl2 to 100%
CH2Cl2) gave 18p (5.0 mg, 8%) and a mixture of acetamides (18m
and 18n). HPLC of the mixture (Chiralpak IB column, 2% EtOH/n-
hexane, 0.7 mL/min) gave 18m (20.0 mg, 34%) and 18n (20.0 mg,
34%). See Table 4, entry 2.
N-((S)-(4-(tert-Butyl)phenyl)((1R,2S,3R)-3-(4-(tert-butyl)phenyl)-2-
(3,5-dimethylphenyl)-4,6-dimethyl-2,3-dihydro-1H-inden-1-yl)-
methyl)acetamide (18m). Colorless oil; 1H NMR (CDCl3, 400 MHz)
δ 1.31 (18H, s), 1.66 (3H, s), 1.88 (3H, s), 2.18 (6H, s), 2.20 (3H, s),
3.15 (1H, t, J = 8.2 Hz), 3.68 (1H, t, J = 8.2 Hz), 4.34 (1H, d, J = 8.2
Hz), 5.29 (1H, t, J = 8.2 Hz), 5.42 (1H, d, J = 8.2 Hz), 6.31 (1H, s),
6.44 (2H, s), 6.78 (1H, s), 6.87 (1H, s), 6.88 (2H, d, J = 7.8 Hz), 7.09
(2H, d, J = 8.7 Hz), 7.26 (2H, d, J = 7.8 Hz), 7.30 (2H, d, J = 8.7 Hz);
HRESIMS m/z 586.4030 [M + H]+ (calcd for C42H51NO + H,
586.4049).
N-((R)-(4-(tert-Butyl)phenyl)((1R,2S,3R)-3-(4-(tert-butyl)phenyl)-2-
(3,5-dimethylphenyl)-4,6-dimethyl-2,3-dihydro-1H-inden-1-yl)-
methyl)acetamide (18n). Colorless oil; 1H NMR (CDCl3, 400 MHz)
δ 1.27 (9H, s), 1.30 (9H, s), 1.76 (3H, s), 1.80 (3H, s), 2.24 (3H, s),
2.26 (6H, s), 3.14 (1H, t, J = 6.0 Hz), 3.80 (1H, t, J = 6.0 Hz), 4.31
(1H, d, J = 8.0 Hz), 5.43 (1H, dd, J = 9.2, 6.0 Hz), 5.65 (1H, d, J = 9.2
Hz), 6.46 (1H, s), 6.73 (2H, s), 6.76 (2H, d, J = 8.7 Hz), 6.86 (1H, s),
ASSOCIATED CONTENT
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S
* Supporting Information
1H and 13C NMR (except 3d, 4d, and 5d) spectra for stilbenes
and electrochemical oxidation products. Experimental proce-
dure and compound characterization data for the synthesis and
anodic oxidation of stilbenes. Representative cyclic voltammo-
grams of selected stilbenes. X-ray structures and crystallo-
4541
dx.doi.org/10.1021/jo500559r | J. Org. Chem. 2014, 79, 4528−4543