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δ): 1.30 [d, J = 6.0 Hz, 6H, OCH(CH3)2], 2.36 (s, 3H, ArCH3), 3.81 (s, 3H,
OCH3), 4.49 [sept, J = 6.0 Hz, 1H, OCH(CH3)2], 6.32 (d, J = 2.7 Hz, 1H,
ArH), 6.41 (d, J = 2.7 Hz, 1H, ArH); 13C NMR (100 MHz, CDCl3, δ): 21.8,
23.3, 55.9, 69.8, 98.7, 104.5, 109.0, 139.4, 156.4, 157.3. Anal. calcd. for
C11H15BrO2: C 50.98, H 5.83, Br 30.83; found: C 50.94, H 5.45, Br 30.68.
chromatography with hexane–ethyl acetate (7:1) as an eluent to give ester
11 (4.96 g, 98%) as crystals, mp 84.8–86.5 °C; 1H NMR (400 MHz, CDCl3,
δ): 1.44 [d, J = 6.0 Hz, 6H, OCH(CH3)2], 4.10 (s, 3H, OCH3), 4.75 [sept, J =
6.0 Hz, 1H, OCH(CH3)2], 6.81 (d, J = 2.4 Hz, 1H, ArH), 6.90 (d, J = 2.4 Hz,
1H, ArH), 7.60 (s, 1H, ArH), 7.63 (ddd, J = 7.6, 7.1, 1.1 Hz, 1H, ArH), 7.70
(ddd, J = 8.3, 7.1, 1.5 Hz, 1H, ArH), 8.10 (dd, J = 8.3, 1.1 Hz, 1H, ArH), 9.60
(d, J = 7.6 Hz, 1H, ArH); 13C NMR (100 MHz, CDCl3, δ): 22.0, 55.8, 70.1,
101.8, 103.6, 114.7, 117.0, 117.7, 120.8, 124.4, 125.9, 127.9, 128.0, 132.2,
133.8, 145.1, 157.2, 159.9; IR (KBr): ν = 3651, 1610 cmÀ1. Anal. calcd. for
C19H17F3O5S: C 55.07, H 4.13; found: C 55.04, H 4.04.
2,6-Di-tert-butyl-4-methoxyphenyl 4’-isopropoxy-2’-methoxy-6’-
methyl-1,1’-biphenyl-2-carboxylate (9). Magnesium
turnings
(1.03 g, 42.4 mmol) was activated with 1,2-dibromoethane (30 μl) in
dry THF (10 ml) under ultrasonic irradiation (53 W, 41 kHz) for
10 min. To the suspension was added dropwise a mixed solution of
compound 7 (5.50 g, 21.2 mmol) and 1,2-dibromoethane (50 μl) in
dry THF (40 ml) over a period of 1 h, and the mixture was irradiated
for a further 1 h. The solvent was evaporated under reduced pres-
sure to leave a residue, which was dried in vacuo for 2 h and then
dissolved by the addition of dry benzene (50 ml) under ultrasonic ir-
radiation to give a Grignard solution of compound 7. The Grignard
solution was added dropwise to a solution of compound 8 (5.24 g,
14.2 mmol) in dry benzene (50 ml) over a period of 30 min, and the
mixture was refluxed for 2 h. After cooling, the mixture was
quenched with saturated aqueous NH4Cl, and the resulting mixture
was extracted with diethyl ether. The extract was washed succes-
sively with water and saturated aqueous NH4Cl, dried over MgSO4,
and evaporated. The residue was purified by column chromatogra-
phy with hexane–ethyl acetate (20:1) as an eluent to give biphenyl
9 (7.25 g, 99%) as a colorless powder, mp 154–155 °C; 1H NMR
(400 MHz, CDCl3, δ): 1.28 [s, 9H, C(CH3)3], 1.29 [s, 9H, C(CH3)3],
1.31 [d, J = 6.0 Hz, 3H, OCH(CH3)2], 1.32 [d, J = 6.0 Hz, 3H,
OCH(CH3)2], 1.86 (s, 3H, ArCH3), 3.52 (s, 3H, OCH3), 3.75 (s, 3H,
OCH3), 4.50[(sept, J = 6.0 Hz, 1H, OCH(CH3)2], 6.23 (d, J = 2.0 Hz,
1H, ArH), 6.30 (d, J = 2.0 Hz, 1H, ArH), 6.81 (d, J = 3.0 Hz, 1H,
ArH), 6.82 (d, J = 3.0 Hz, 1H, ArH), 7.23 (d, J = 7.5 Hz, 1H, ArH),
7.53 (t, J = 7.5 Hz, 1H, ArH), 7.65 (t, J = 7.5 Hz, 1H, ArH), 8.51 (d,
J = 7.5 Hz, 1H, ArH); 13C NMR (100 MHz, CDCl3, δ): 20.4, 22.3,
22.4, 31.4, 31.5, 35.6, 35.7, 55.3, 55.3, 69.4, 96.9, 107.2, 111.6,
111.7, 123.0, 127.5, 129.3, 131.6, 132.8, 133.0, 136.6, 141.8, 142.4,
143.6, 143.9, 156.2, 157.3, 157.8, 165.1; IR (KBr): ν = 2946,
1745 cmÀ1. Anal. calcd. for C33H42O5: C 76.42, H 8.16; found: C
76.17, H 8.06.
2-Isopropoxy-4-methoxyphenanthrene (12). A mixture of ester 11
(4.14 g, 9.98 mmol), palladium acetate (45.0 mg, 0.20 mmol),
triphenylphosphine (130 mg, 0.50 mmol), dry triethylamine (d 0.726;
4.17 ml, 29.9 mmol), and dry DMF (35 ml) was stirred at room tempera-
ture for 10 min. To it was added formic acid (d 1.22; 840 μl, 22.3 mmol),
and the mixture was stirred at 65 °C for 2 h. The mixture was quenched
with water and acidified by the addition of 2 M HCl. The resulting mixture
was extracted with ethyl acetate, and the extract was washed successively
with water and brine, dried over MgSO4, and evaporated. The residue
was purified by column chromatography with hexane–ethyl acetate
(20:1) as an eluent to give phenanthrene 12 (2.61 g, 98%) as crystals,
1
mp 64.5–65.8 °C; H NMR (400 MHz, CD2Cl2, δ): 1.43 [d, J = 6.0 Hz, 6H,
OCH(CH3)2], 4.09 (s, 3H, OCH3), 4.75 [sept, J = 6.0 Hz, 1H, OCH(CH3)2],
6.76 (d, J = 2.4 Hz, 1H, ArH), 6.89 (d, J = 2.4 Hz, 1H, ArH), 7.50 (ddd, J =
7.5, 7.4, 1.1 Hz, 1H, ArH), 7.58 (ddd, J = 8.0, 7.5, 1.5 Hz, 1H, ArH), 7.58
(d, J = 8.7 Hz, 1H, ArH), 7.70 (d, J = 8.7 Hz, 1H, ArH), 7.83 (dd, J = 8.0,
1.1 Hz, 1H, ArH), 9.52 (dd, J = 7.4 Hz, 1H, ArH); 13C NMR (100 MHz,
CDCl3, δ): 22.1, 55.7, 69.8, 100.6, 103.4, 115.4, 124.8, 126.4, 126.8, 127.6,
128.2, 128.3, 130.5, 131.7, 135.5, 156.4, 160.1; IR (KBr): ν = 1589 cmÀ1
.
Anal. calcd. for C18H18O2: C 81.17, H 6.81; found: C 81.15, H 6.91.
4-Methoxyphenanthren-2-ol (13). To an ice-cold solution of com-
pound 12 (120 mg, 0.45 mmol) in dry dichloromethane (5 ml) was added
dropwise BCl3 (1.0 M in heptane; 2.25 ml, 2.25 mmol), and the mixture
was stirred at room temperature for 4.5 h. The mixture was quenched
by slowly adding water in an ice-water bath and the resulting mixture
was extracted with ethyl acetate. The extract was washed successively
with water and brine, dried over MgSO4, and evaporated. The residue
was purified by column chromatography with hexane–ethyl acetate
(2:1) as an eluent to give phenanthrol 13 (82.4 mg, 81%) as crystals, mp
2-Isopropoxy-4-methoxyphenanthren-9-ol (10). To an ice-cold solu-
tion of diethylamine (d 0.707; 6.37 ml, 61.6 mmol) in dry THF (40 ml) was
added dropwise butyllithium (1.59 M in hexane; 35.4 ml, 56.0 mmol), and
the solution was stirred for 1 h. The solution was added dropwise over a
period of 40 min to an ice-cold solution of biphenyl 9 (7.24 g, 14.0 mmol)
in THF–HMPA (2:1 v/v; 60 ml). After stirring at 0 °C for 1 h, the mixture
was quenched with water and acidified by the addition of 2 M HCl. The
resulting mixture was extracted with diethyl ether, and the extract was
washed successively with water and brine, dried over MgSO4, and evap-
orated. The residue was purified by column chromatography with
hexane–ethyl acetate (4:1) as an eluent to give phenanthrol 10 as a foam
(3.29 g, 84%), 1H NMR (400 MHz, CDCl3, δ): 1.40 [d, J = 6.0 Hz, 6H,
OCH(CH3)2], 4.06 (s, 3H, OCH3), 4.69 [sept, J = 6.0 Hz, 1H, OCH(CH3)2],
5.86 (s, 1H, ArOH), 6.61 (d, J = 2.4 Hz, 1H, ArH), 6.67 (d, J = 2.4 Hz, 1H,
ArH), 6.85 (s, 1H, ArH), 7.52 (ddd, J = 8.1, 6.9, 1.2 Hz, 1H, ArH), 7.63
(ddd, J = 8.6, 6.9, 1.6 Hz, 1H, ArH), 8.29 (dd, J = 8.1, 1.6 Hz, 1H, ArH),
9.53 (dd, J = 8.6, 1.2 Hz, 1H, ArH); 13C NMR (100 MHz, CDCl3, δ): 22.2,
31.1, 55.7, 69.9, 98.5, 102.1, 106.5, 121.7, 124.7, 124.8, 127.2, 127.6, 131.9,
1
123.9–125.8 °C; H NMR (400 MHz, CDCl3, δ): 4.10 (s, 3H, OCH3), 5.03
(s, 1H, ArH), 6.75 (d, J = 2.0 Hz, 1H, ArH), 6.87 (d, J = 2.0 Hz, 1H, ArH),
7.51 (ddd, J = 6.3, 5.6, 0.9 Hz, 1H, ArH), 7.54 (d, J = 7.0 Hz, 1H, ArH),
7.60 (ddd, J = 6.9, 5.6, 1.3 Hz, 1H, ArH), 7.69 (d, J = 7.0 Hz, 1H, ArH),
7.83 (dd, J = 6.3, 1.3 Hz, 1H, ArH), 9.52 (d, J = 6.9 Hz, 1H, ArH); 13C
NMR (100 MHz, CDCl3, δ): 55.6, 98.8, 104.8, 115.3, 125.0, 126.3, 126.5,
127.5, 128.3, 128.6, 130.4, 131.6, 135.5, 154.0, 160.2; IR (KBr): ν = 3323,
1616 cmÀ1. Anal. calcd. for C15H12O2: C 80.34, H 5.39; found: C 80.14,
H 5.56.
4,4’-Dimethoxy-1,1’-biphenanthrene-2,2’-diol (3).
A mixture of
Cu(NO3)2 · 3H2O (620 mg, 2.57 mmol), 1-phenylethylamine (d 0.94;
1.19 ml, 9.23 mmol), and dry methanol (10 ml) was stirred at room temper-
ature for 1 h. To the mixture was added dropwise a solution of phenanthrol
13 (287 mg, 1.28 mmol) in dry methanol (10 ml) over a period of 30 min,
and the mixture was stirred for 4 h. After most of the methanol was evap-
orated under reduced pressure, the mixture was quenched with water in
an ice-water bath. The resulting mixture was extracted with ethyl acetate,
and the extract was washed successively with water and brine, dried over
MgSO4, and evaporated. The residue was purified by column chromatog-
raphy with hexane–ethyl acetate (4:1) as an eluent to give biphenanthrol 3
(285 mg, 99%) as crystals, α = 2.06, Rs = 2.20 [Daicel CHIRALPAK AD
(250 mm × 4.6 mm i.d.), hexane–ethanol (1:1)]; mp 326.0–327.8 °C; 1H
NMR (400 MHz, CDCl3, δ): 4.23 (s, 6H, OCH3), 5.15 (s, 2H, ArOH), 7.07
(s, 2H, ArH), 7.12 (d, J = 9.0 Hz, 2H, ArH), 7.54 (ddd, J = 9.3, 7.2, 1.1 Hz,
2H, ArH), 7.57 (d, J = 9.0 Hz, 2H, ArH), 7.66 (ddd, J = 9.2, 7.2, 1.5 Hz, 2H,
ArH), 7.80 (dd, J = 9.2, 1.1 Hz, 2H, ArH), 9.45 (d, J = 9.3 Hz, 2H, ArH); 13C
NMR (100 MHz, CDCl3, δ): 55.9, 98.4, 105.6, 116.4, 123.3, 125.4, 126.9,
136.2, 150.4, 156.6, 160.1; IR (KBr): ν = 3371, 1596 cmÀ1
.
2-Isopropoxy-4-methoxyphenanthren-9-yl trifluoromethanesulfonate
(11). To a mixed solution of phenanthrol 10 (3.29 g, 11.7 mmol) and dry
triethylamine (d 0.726; 4.87 ml, 35.1 mmol) in dry dichloromethane (50 ml)
was added dropwise trifluoromethanesulfonic anhydride (d = 1.677;
2.94 ml, 17.6 mmol) at –78 °C, and the mixture was stirred at this tempera-
ture for 3.5 h. The mixture was quenched with water, and acidified by the
addition of 2 M HCl. The resulting mixture was extracted with diethyl ether,
and the extract was washed successively with water and brine, dried over
MgSO4, and evaporated. The residue was purified by column
Chirality DOI 10.1002/chir