(ArCH), 125.9 (2 × ArCH), 126.9 (6-Ca), 127.2 [ArC(Ph)᎐
72%), 320 (17), 302 (50), 291 (100), 287 (13), 193 (62), 127 (30)
and 91 (7).
᎐
a
CHCH ], 128.3 (2 × ArCHa), 129.0 (1-C), 134.4 [ArC(Ph)᎐
᎐
3
CHCH3], 138.0 (ArCb), 141.6 (2-Cb), 144.3 (4-Cc), 158.4 (3-Cc)
and 191.7 (CHO); m/z 310 (Mϩ, 43%), 295 (20), 281 (10), 267
(33), 253 (100), 239 (59) and 149 (22).
(2Ј-Allyl-3Ј-isopropoxy-4Ј-methoxyphenyl)(3Љ,4Љ-dimethoxy-
phenyl)methanol. (72%) From 3,4-dimethoxyphenyllithium
8c (made in THF from bromoveratrole, n-butyllithium and
TMEDA) and aldehyde 6a (reaction time 15 min at Ϫ78 ЊC,
30 min at rt), as a clear oil (Found: Mϩ, 372.1935. C22-
H28O5 requires M, 372.1937); νmax(film)/cmϪ1 3598 (OH), 2838
General procedure for preparing diaryl ketones 9
(a) Preparation of diarylmethanols. Typically, lithium metal
(2.0 mmol) was added to dry diethyl ether (20 cm3) in a Schlenk
tube. The bromoarene (2.0 mmol) was added and the reaction
mixture was stirred under nitrogen for 18 h. The aryllithium 8
generated in this way was added dropwise through a cannula to
a stirred solution of aldehyde 6a (1.32 mmol) in dry diethyl
ether (10 cm3), and the reaction mixture was stirred at 0 ЊC for
the specified time. The mixture was allowed to warm to room
temperature and stirred for a further period under nitrogen.
The reaction mixture was diluted with water, the solution was
extracted into diethyl ether, and the organic layer was dried
with magnesium sulfate. Filtration, and evaporation of the
solvent under reduced pressure, afforded a brown residue, which
was subjected to chromatography (5–10% ethyl acetate–hexane)
to afford the intermediate methanols. The following compounds
were prepared by this method. (Yields are reported in Table 2.)
(2-Allyl-3-isopropoxy-4-methoxyphenyl)(phenyl)methanol.
(82%) From phenyllithium 8a and aldehyde 6a (reaction
time 30 min at 0 ЊC, 3 h at rt), as a clear oil (Found: Mϩ,
312.1718. C20H24O3 requires M, 312.1725); νmax(film)/cmϪ1
(OCH ), 1514 (ArC᎐C), 1439 (CH CH᎐CH ), 1267 and 1216
᎐ ᎐
3 2 2
(C–O) and 774 (Ar–H oop); δH (400 MHz; CDCl3; Me4Si) 1.25
and 1.27 [each 3H, d, J 6.3, CH(CH3)2], 2.13 (1H, br s, OH),
3.38 (1H, br dd, J 6.1 and 15.8, one of ArCH CH᎐CH ), 3.65
᎐
2
2
(1H, br dd, J 5.3 and 15.8, one of ArCH CH᎐CH ), 3.81, 3.82
᎐
2
2
and 3.86 (each 3H, s, OCH3), 4.54 [1H, sept, J 6.3, CH(CH3)2],
4.94 [1H, dd, J 1.5 and 17.2, (Z)-ArCH CH᎐CH ], 5.01 [1H,
᎐
2
2
dd, J 1.5 and 10.2, (E)-ArCH CH᎐CH ], 5.91–6.01 [2H, m,
᎐
2
2
ArCH CH᎐CH and ArCH(OH)Ar], 6.78–6.83 (2H, m, 5Љ- and
᎐
2
2
6Љ-H), 6.78 (1H, d, J 8.5, 5Ј-H), 6.87 (1H, s, 2Љ-H) and 7.04
(1H, d, J 8.5, 6Ј-H); δC (100.625 MHz; CDCl3) 22.5 and 22.7
[CH(CH ) ], 30.4 (ArCH CH᎐CH ), 55.5, 55.8 and 55.9 (each
᎐
3
2
2
2
OCH3), 72.1 [ArCH(OH)Ar], 74.5 [CH(CH3)2], 110.2 (2Љ-Ca),
110.8 (5Љ-Ca), 115.1 (5Ј-Ca and ArCH CH᎐CH ), 119.0 (6Љ-Cb),
᎐
2
2
122.4 (6Ј-Cb), 131.8 (2Ј-Cb), 135.2 (1Ј-Cb), 136.3 (1Љ-Cb), 137.5
b
(ArCH CH᎐CH ), 144.9 (4Љ-Cc), 148.2 (4Ј-Cc), 148.8 (3Љ-Cc)
᎐
2
2
and 152.2 (3Ј-Cc); m/z 372 (Mϩ, 100%), 355 (24), 330 (45), 313
(59), 312 (60), 301 (70), 271 (88), 193 (63), 192 (35), 165 (68),
151 (56) and 91 (14).
3422 (OH), 2836 (OCH ), 1636, 1598 and 1579 (ArC᎐C), 1437
(b) Oxidation of diarylmethanols to diaryl ketones. Typically,
a solution of the intermediate alcohol (0.48 mmol) in dry ben-
zene (5 cm3) was added to a suspension of manganese() oxide
(10 mass equiv.) in dry benzene (5 cm3), and the mixture was
stirred at room temperature for 90 min. The reaction mixture
was filtered through Celite, the solvent evaporated under
reduced pressure, and the residue purified by column chrom-
atography (20% ethyl acetate–hexane) to afford the desired
ketones 9. The following compounds were prepared by this
method. (Overall yields in two steps from aldehydes 6 are
reported in Table 2.)
᎐
3
(CH CH᎐CH ), 1272 (C–O) and 700 (Ar–H oop); δ (200
᎐
2
2
H
MHz; CDCl3; Me4Si) 1.24 and 1.27 [each 3H, d, J 6.2,
CH(CH3)2], 2.21 [1H, br s, ArCH(OH)], 3.40 (1H, tdd, J 1.7, 6.0
and 15.8, ArCH CH᎐CH ), 3.65 (1H, tdd, J 1.9, 5.4 and
᎐
2
2
15.8, ArCH CH᎐CH ), 3.80 (3H, s, OCH ), 4.52 [1H, sept,
᎐
2
2
3
J 6.2, CH(CH3)2], 4.94 [1H, tdd, J 1.7, 3.4 and 17.2, (Z)-
ArCH CH᎐CH ], 5.02 [1H, tdd, J 1.7, 3.4 and 10.2, (E)-
᎐
2
2
ArCH CH᎐CH ], 5.95 (1H, m, ArCH CH᎐CH ), 6.01 (1H, br
᎐
᎐
2
2
2
2
s, OH), 6.75 (1H, d, J 8.6, 5-H), 6.98 (1H, d, J 8.6, 6-H) and
7.22–7.31 (5H, m, ArH); δC (50.32 MHz; CDCl3) 22.5 and 22.6
[CH(CH3)2], 30.4 (ArCH CH᎐CH ), 55.5 (OCH3), 72.2
2Ј-Allyl-3Ј-isopropoxy-4Ј-methoxybenzophenone 9a. (97%)
Clear oil (Found: Mϩ, 310.1561. C20H22O3 requires M,
310.1569); νmax(film)/cmϪ1 2840 (OCH ), 1657 (C᎐O), 1589
᎐
2
2
[ArCH(OH)Ar], 74.5 [CH(CH3)2], 110.2 (5-C), 115.1 (ArCH2-
CH᎐CH ), 122.6 (6Ј-Ca), 126.7 (2 × ArCH), 127.1 (ArCHa),
᎐
᎐
2
3
128.2 (2 × ArCH), 131.9 (1Ј-C), 135.2 (ArC), 137.5 (ArCH2-
(ArC᎐C), 1428 (CH CH᎐CH ), 1274 (C–O) and 919 (Ar–H
᎐ ᎐
2 2
oop); δH (200 MHz; CDCl3; Me4Si) 0.91 [6H, d, J 6.2,
CH᎐CH ), 143.6 (2Ј-Cb), 144.9 (4Ј-Cb) and 152.1 (3Ј-Cb); m/z
᎐
2
312 (Mϩ, 47%), 294 (9), 270 (16), 252 (34), 237 (14), 193 (100),
105 (28), 91 (21) and 77 (32).
CH(CH ) ], 3.23–3.26 (2H, m, ArCH CH᎐CH ), 3.48 (3H, s,
᎐
3
2
2
2
OCH3), 4.16 [1H, sept, J 6.2, CH(CH3)2], 4.40–4.45 (2H, m,
ArCH CH᎐CH ), 5.39–5.46 (1H, m, ArCH CH᎐CH ), 6.37
(2Ј-Allyl-3Ј-isopropoxy-4Ј-methoxyphenyl)(1Љ-naphthyl)-
methanol. (77%) From 1-naphthyllithium 8b (30 min for
preparation) and aldehyde 6a (reaction time 2 h at rt), as a clear
oil (Found: Mϩ, 362.1891. C24H26O3 requires M, 362.1882);
νmax(CHCl3)/cmϪ1 3596 (OH), 2838 (OCH3), 1636, 1598 and
1579 (ArC᎐C), 1432 (CH CH᎐CH ) and 1211 (C–O); δ (400
᎐
᎐
2
2
2
2
(1H, d, J 8.5, 5Ј-H), 6.63 (1H, d, J 8.5, 6Ј-H), 7.00–7.04 (2H, m,
Ph), 7.12–7.16 (1H, m, Ph) and 7.34–7.36 (2H, m, Ph); δC (50.32
MHz; CDCl ) 22.6 [CH(CH ) ], 30.7 (ArCH CH᎐CH ), 55.6
᎐
3
3
2
2
2
(OCH ), 74.9 [CH(CH ) ], 108.6 (5Ј-C), 115.4 (ArCH CH᎐
᎐
3
3
2
2
CH2), 125.7 (ArCHa), 128.1 (2 × ArCH), 130.2 (2 × ArCH),
132.0 (2Ј-C), 132.6 (6Ј-Ca), 134.6 (ArCb), 136.8 (ArCH2-
CH᎐CH ), 138.5 (1Ј-Cb), 145.3 (4Ј-Cc), 154.8 (3Ј-Cc) and 197.7
᎐
᎐
2
2
H
MHz; CDCl3; Me4Si) 0.85 and 0.86 [each 3H, d, J 6.2,
CH(CH3)2], 1.96 [1H, br s, ArCH(OH)Ar], 3.01 (1H, tdd, J 1.6,
᎐
2
6.1 and 15.5, one of ArCH CH᎐CH ), 3.32 (3H, s, OCH ), 3.38
(CO); m/z 310 (Mϩ, 25%), 295 (4), 268 (33), 267 (18), 253 (100),
191 (17), 105 (32), 91 (5) and 77 (29).
᎐
2
2
3
(1H, tdd, J 1.7, 5.7 and 15.5, one of ArCH CH᎐CH ), 4.14
᎐
2
2
[1H, sept, J 6.2, CH(CH3)2], 4.58 [1H, tdd, J 1.7, 3.3 and 17.3,
2Ј-Allyl-3Ј-isopropoxy-4Ј-methoxyphenyl 1Љ-naphthyl ketone
9b. (100%) Clear oil (Found: Mϩ, 360.1720. C24H24O3 requires
M, 360.1725); νmax(film)/cmϪ1 2840 (OCH ), 1652 (C᎐O), 1588
(Z)-ArCH CH᎐CH ], 4.62 [1H, tdd, J 1.6, 3.3 and 10.3, (E)-
᎐
2
2
ArCH CH᎐CH ], 5.55–5.67 (1H, m, ArCH CH᎐CH ), 6.19
᎐
᎐
᎐
2
2
2
2
3
(1H, d, J 8.6, 5Ј-H), 6.26 [1H, br s, ArCH(OH)Ar], 6.36 (1H, d,
J 8.6, 6Ј-H), 6.92–6.97 (2H, m, 6Љ- and 7Љ-H), 6.99 (1H, dd, J 7.1
and 7.6, 3Љ-H), 7.10 (1H, d, J 7.1, 2Љ-H), 7.34 (1H, d, J 8.2, 5Љ-
Ha), 7.40 (1H, br d, J 7.6, 4Љ-H) and 7.41 (1H, br d, J 8.1, 8Љ-
Ha); δC (100.625 MHz; CDCl3) 22.6 and 22.5 [CH(CH3)2], 30.7
and 1568 (ArC᎐C), 1428 (CH CH᎐CH ), 1212 (C–O) and 786
᎐ ᎐
2 2
(Ar–H oop); δH (400 MHz; CDCl3; Me4Si) 0.88 [6H, d, J 6.2,
CH(CH3)2], 3.39 (3H, s, OCH3), 3.39–3.41 (2H, m, ArCH2-
CH᎐CH ), 4.13 [1H, sept, J 6.2, CH(CH ) ], 4.46–4.51 (2H, m,
᎐
2
3 2
ArCH CH᎐CH ), 5.51 (1H, tdd, J 6.3, 10.4 and 16.9, ArCH -
᎐
2
2
2
(ArCH CH᎐CH ), 55.3 (OCH ), 69.2 [ArCH(OH)Ar], 74.4
CH᎐CH ), 6.20 (1H, d, J 8.5, 5Ј-H), 6.60 (1H, d, J 8.5, 6Ј-H),
᎐
᎐
2
2
3
2
[CH(CH ) ], 109.9 (5-C), 115.2 (CH CH᎐CH ), 122.6 (ArCH),
123.9 (ArCH), 124.1 (ArCH), 125.2 (ArCH), 125.4 (ArCH),
125.9 (ArCH), 128.0 (ArCH), 128.5 (ArCH), 130.8 (ArC),
6.95 (1H, dd, J 7.1 and 8.2, 3Љ-H), 7.05–7.09 (2H, m, 6Љ- and
7Љ-H), 7.05 (1H, d, J 7.1, 2Љ-H), 7.43 (1H, m, 5Љ-Ha), 7.49 (1H,
d, J 8.2, 4Љ-H) and 7.95 (1H, m, 8Љ-Ha); δC (100.625 MHz;
᎐
3
2
2
2
132.0 (ArC), 133.6 (ArC), 134.4 (ArC), 137.5 (CH CH᎐CH ),
CDCl ) 22.5 [CH(CH ) ], 30.7 (ArCH CH᎐CH ), 55.5 (OCH ),
᎐
3 3 2 2 2 3
74.8 [CH(CH ) ], 108.5 (5Ј-C), 115.3 (ArCH CH᎐ CH ), 124.2
᎐
3 2 2 2
᎐
2
2
138.8 (2Ј-C), 144.9 (4Ј-Ca) and 152.2 (3Ј-Ca); m/z 362 (Mϩ,
792 J. Chem. Soc., Perkin Trans. 1, 2000, 787–797